Installation and Configuration

OpenShift Container Platform 3.7

OpenShift Container Platform 3.7 Installation and Configuration

Red Hat OpenShift Documentation Team

Abstract

OpenShift Installation and Configuration topics cover the basics of installing and configuring OpenShift in your environment. Use these topics for the one-time tasks required to get OpenShift up and running.

Chapter 1. Overview

OpenShift Container Platform Installation and Configuration topics cover the basics of installing and configuring OpenShift Container Platform in your environment. Configuration, management, and logging are also covered. Use these topics for the one-time tasks required to quickly set up your OpenShift Container Platform environment and configure it based on your organizational needs.

For day to day cluster administration tasks, see Cluster Administration.

Chapter 2. Installing a Cluster

2.1. Planning

2.1.1. Initial Planning

For production environments, several factors influence installation. Consider the following questions as you read through the documentation:

  • Which installation method do you want to use? The Installation Methods section provides some information about the quick and advanced installation methods.
  • How many hosts do you require in the cluster? The Environment Scenarios section provides multiple examples of Single Master and Multiple Master configurations.
  • How many pods are required in your cluster? The Sizing Considerations section provides limits for nodes and pods so you can calculate how large your environment needs to be.
  • Is high availability required? High availability is recommended for fault tolerance. In this situation, you might aim to use the Multiple Masters Using Native HA example as a basis for your environment.
  • Which installation type do you want to use: RPM or containerized? Both installations provide a working OpenShift Container Platform environment, but you might have a preference for a particular method of installing, managing, and updating your services.
  • Is my installation supported if integrating with other technologies? See the OpenShift Container Platform Tested Integrations for a list of tested integrations.

2.1.2. Installation Methods

Both the quick and advanced installation methods are supported for development and production environments. If you want to quickly get OpenShift Container Platform up and running to try out for the first time, use the quick installer and let the interactive CLI guide you through the configuration options relevant to your environment.

For the most control over your cluster’s configuration, you can use the advanced installation method. This method is particularly suited if you are already familiar with Ansible. However, following along with the OpenShift Container Platform documentation should equip you with enough information to reliably deploy your cluster and continue to manage its configuration post-deployment using the provided Ansible playbooks directly.

If you install initially using the quick installer, you can always further tweak your cluster’s configuration and adjust the number of hosts in the cluster using the same installer tool. If you wanted to later switch to using the advanced method, you can create an inventory file for your configuration and carry on that way.

2.1.3. Sizing Considerations

Determine how many nodes and pods you require for your OpenShift Container Platform cluster. Cluster scalability correlates to the number of pods in a cluster environment. That number influences the other numbers in your setup. See Cluster Limits for the latest limits for objects in OpenShift Container Platform.

2.1.4. Environment Scenarios

This section outlines different examples of scenarios for your OpenShift Container Platform environment. Use these scenarios as a basis for planning your own OpenShift Container Platform cluster, based on your sizing needs.

Note

Moving from a single master cluster to multiple masters after installation is not supported.

2.1.4.1. Single Master and Node on One System

OpenShift Container Platform can be installed on a single system for a development environment only. An all-in-one environment is not considered a production environment.

2.1.4.2. Single Master and Multiple Nodes

The following table describes an example environment for a single master (with embedded etcd) and two nodes:

Host NameInfrastructure Component to Install

master.example.com

Master and node

node1.example.com

Node

node2.example.com

2.1.4.3. Single Master, Multiple etcd, and Multiple Nodes

The following table describes an example environment for a single master, three etcd hosts, and two nodes:

Host NameInfrastructure Component to Install

master.example.com

Master and node

etcd1.example.com

etcd

etcd2.example.com

etcd3.example.com

node1.example.com

Node

node2.example.com

Note

When specifying multiple etcd hosts, external etcd is installed and configured. Clustering of OpenShift Container Platform’s embedded etcd is not supported.

2.1.4.4. Multiple Masters Using Native HA

The following describes an example environment for three masters, one HAProxy load balancer, three etcd hosts, and two nodes using the native HA method:

Host NameInfrastructure Component to Install

master1.example.com

Master (clustered using native HA) and node

master2.example.com

master3.example.com

lb.example.com

HAProxy to load balance API master endpoints

etcd1.example.com

etcd

etcd2.example.com

etcd3.example.com

node1.example.com

Node

node2.example.com

Note

When specifying multiple etcd hosts, external etcd is installed and configured. Clustering of OpenShift Container Platform’s embedded etcd is not supported.

2.1.4.5. Stand-alone Registry

You can also install OpenShift Container Platform to act as a stand-alone registry using the OpenShift Container Platform’s integrated registry. See Installing a Stand-alone Registry for details on this scenario.

2.1.5. RPM vs Containerized

An RPM installation installs all services through package management and configures services to run within the same user space, while a containerized installation installs services using container images and runs separate services in individual containers.

See the Installing on Containerized Hosts topic for more details on configuring your installation to use containerized services.

2.2. Prerequisites

2.2.1. System Requirements

The following sections identify the hardware specifications and system-level requirements of all hosts within your OpenShift Container Platform environment.

2.2.1.1. Red Hat Subscriptions

You must have an active OpenShift Container Platform subscription on your Red Hat account to proceed. If you do not, contact your sales representative for more information.

Important

OpenShift Container Platform 3.7 requires Docker 1.12.

2.2.1.2. Minimum Hardware Requirements

The system requirements vary per host type:

Masters

  • Physical or virtual system, or an instance running on a public or private IaaS.
  • Base OS: RHEL 7.3 or 7.4 with the "Minimal" installation option and the latest packages from the Extras channel, or RHEL Atomic Host 7.4.2 or later.
  • 2 vCPU.
  • Minimum 16 GB RAM.
  • Minimum 40 GB hard disk space for the file system containing /var/. redcircle 1
  • Minimum 1 GB hard disk space for the file system containing /usr/local/bin/.
  • Minimum 1 GB hard disk space for the file system containing the system’s temporary directory. redcircle 2

Nodes

  • Physical or virtual system, or an instance running on a public or private IaaS.
  • Base OS: RHEL 7.3 or 7.4 with "Minimal" installation option, or RHEL Atomic Host 7.4.2 or later.
  • NetworkManager 1.0 or later.
  • 1 vCPU.
  • Minimum 8 GB RAM.
  • Minimum 15 GB hard disk space for the file system containing /var/. redcircle 1
  • Minimum 1 GB hard disk space for the file system containing /usr/local/bin/.
  • Minimum 1 GB hard disk space for the file system containing the system’s temporary directory. redcircle 2
  • An additional minimum 15 GB unallocated space to be used for Docker’s storage back end; see Configuring Docker Storage.

External etcd Nodes

  • Minimum 20 GB hard disk space for etcd data.
  • Consult Hardware Recommendations to properly size your etcd nodes.
  • Currently, OpenShift Container Platform stores image, build, and deployment metadata in etcd. You must periodically prune old resources. If you are planning to leverage a large number of these resources, place etcd on machines with large amounts of memory and fast SSD drives.

redcircle 1 Meeting the /var/ file system sizing requirements in RHEL Atomic Host requires making changes to the default configuration. See Managing Storage in Red Hat Enterprise Linux Atomic Host for instructions on configuring this during or after installation.

redcircle 2 The system’s temporary directory is determined according to the rules defined in the tempfile module in Python’s standard library.

Important

OpenShift Container Platform only supports servers with the x86_64 architecture.

2.2.1.3. Production Level Hardware Requirements

Test or sample environments function with the minimum requirements. For production environments, the following recommendations apply:

Master Hosts
In a highly available OpenShift Container Platform cluster with external etcd, a master host should have, in addition to the minimum requirements in the table above, 1 CPU core and 1.5 GB of memory for each 1000 pods. Therefore, the recommended size of a master host in an OpenShift Container Platform cluster of 2000 pods would be the minimum requirements of 2 CPU cores and 16 GB of RAM, plus 2 CPU cores and 3 GB of RAM, totaling 4 CPU cores and 19 GB of RAM.

When planning an environment with multiple masters, a minimum of three etcd hosts and a load-balancer between the master hosts are required.

The OpenShift Container Platform master caches deserialized versions of resources aggressively to ease CPU load. However, in smaller clusters of less than 1000 pods, this cache can waste a lot of memory for negligible CPU load reduction. The default cache size is 50,000 entries, which, depending on the size of your resources, can grow to occupy 1 to 2 GB of memory. This cache size can be reduced using the following setting the in /etc/origin/master/master-config.yaml:

kubernetesMasterConfig:
  apiServerArguments:
    deserialization-cache-size:
    - "1000"
Node Hosts
The size of a node host depends on the expected size of its workload. As an OpenShift Container Platform cluster administrator, you will need to calculate the expected workload, then add about 10 percent for overhead. For production environments, allocate enough resources so that a node host failure does not affect your maximum capacity.

Use the above with the following table to plan the maximum loads for nodes and pods:

HostSizing Recommendation

Maximum nodes per cluster

2000

Maximum pods per cluster

120000

Maximum pods per nodes

250

Maximum pods per core

10

Important

Oversubscribing the physical resources on a node affects resource guarantees the Kubernetes scheduler makes during pod placement. Learn what measures you can take to avoid memory swapping.

2.2.1.4. Configuring Core Usage

By default, OpenShift Container Platform masters and nodes use all available cores in the system they run on. You can choose the number of cores you want OpenShift Container Platform to use by setting the GOMAXPROCS environment variable.

For example, run the following before starting the server to make OpenShift Container Platform only run on one core:

# export GOMAXPROCS=1

2.2.1.5. SELinux

Security-Enhanced Linux (SELinux) must be enabled on all of the servers before installing OpenShift Container Platform or the installer will fail. Also, configure SELINUXTYPE=targeted in the /etc/selinux/config file:

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these three values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected.
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted
Using OverlayFS

OverlayFS is a union file system that allows you to overlay one file system on top of another.

As of Red Hat Enterprise Linux 7.4, you have the option to configure your OpenShift Container Platform environment to use OverlayFS. The overlay2 graph driver is fully supported in addition to the older overlay driver. However, Red Hat recommends using overlay2 instead of overlay, because of its speed and simple implementation.

See the Overlay Graph Driver section of the Atomic Host documentation for instructions on how to to enable the overlay2 graph driver for the Docker service.

2.2.1.6. NTP

You must enable Network Time Protocol (NTP) to prevent masters and nodes in the cluster from going out of sync. Set openshift_clock_enabled to true in the Ansible playbook to enable NTP on masters and nodes in the cluster during Ansible installation.

# openshift_clock_enabled=true

2.2.1.7. Security Warning

OpenShift Container Platform runs containers on your hosts, and in some cases, such as build operations and the registry service, it does so using privileged containers. Furthermore, those containers access your host’s Docker daemon and perform docker build and docker push operations. As such, you should be aware of the inherent security risks associated with performing docker run operations on arbitrary images as they effectively have root access.

For more information, see these articles:

To address these risks, OpenShift Container Platform uses security context constraints that control the actions that pods can perform and what it has the ability to access.

2.2.2. Environment Requirements

The following section defines the requirements of the environment containing your OpenShift Container Platform configuration. This includes networking considerations and access to external services, such as Git repository access, storage, and cloud infrastructure providers.

2.2.2.1. DNS

OpenShift Container Platform requires a fully functional DNS server in the environment. This is ideally a separate host running DNS software and can provide name resolution to hosts and containers running on the platform.

Important

Adding entries into the /etc/hosts file on each host is not enough. This file is not copied into containers running on the platform.

Key components of OpenShift Container Platform run themselves inside of containers and use the following process for name resolution:

  1. By default, containers receive their DNS configuration file (/etc/resolv.conf) from their host.
  2. OpenShift Container Platform then inserts one DNS value into the pods (above the node’s nameserver values). That value is defined in the /etc/origin/node/node-config.yaml file by the dnsIP parameter, which by default is set to the address of the host node because the host is using dnsmasq.
  3. If the dnsIP parameter is omitted from the node-config.yaml file, then the value defaults to the kubernetes service IP, which is the first nameserver in the pod’s /etc/resolv.conf file.

As of OpenShift Container Platform 3.2, dnsmasq is automatically configured on all masters and nodes. The pods use the nodes as their DNS, and the nodes forward the requests. By default, dnsmasq is configured on the nodes to listen on port 53, therefore the nodes cannot run any other type of DNS application.

Note

NetworkManager is required on the nodes in order to populate dnsmasq with the DNS IP addresses.

DNSMSQ must be enabled (openshift_use_dnsmasq=true) or the installation will fail and critical features will not function.

The following is an example set of DNS records for the Single Master and Multiple Nodes scenario:

master    A   10.64.33.100
node1     A   10.64.33.101
node2     A   10.64.33.102

If you do not have a properly functioning DNS environment, you could experience failure with:

  • Product installation via the reference Ansible-based scripts
  • Deployment of the infrastructure containers (registry, routers)
  • Access to the OpenShift Container Platform web console, because it is not accessible via IP address alone
2.2.2.1.1. Configuring Hosts to Use DNS

Make sure each host in your environment is configured to resolve hostnames from your DNS server. The configuration for hosts' DNS resolution depend on whether DHCP is enabled. If DHCP is:

  • Disabled, then configure your network interface to be static, and add DNS nameservers to NetworkManager.
  • Enabled, then the NetworkManager dispatch script automatically configures DNS based on the DHCP configuration. Optionally, you can add a value to dnsIP in the node-config.yaml file to prepend the pod’s resolv.conf file. The second nameserver is then defined by the host’s first nameserver. By default, this will be the IP address of the node host.

    Note

    For most configurations, do not set the openshift_dns_ip option during the advanced installation of OpenShift Container Platform (using Ansible), because this option overrides the default IP address set by dnsIP.

    Instead, allow the installer to configure each node to use dnsmasq and forward requests to SkyDNS or the external DNS provider. If you do set the openshift_dns_ip option, then it should be set either with a DNS IP that queries SkyDNS first, or to the SkyDNS service or endpoint IP (the Kubernetes service IP).

To verify that hosts can be resolved by your DNS server:

  1. Check the contents of /etc/resolv.conf:

    $ cat /etc/resolv.conf
    # Generated by NetworkManager
    search example.com
    nameserver 10.64.33.1
    # nameserver updated by /etc/NetworkManager/dispatcher.d/99-origin-dns.sh

    In this example, 10.64.33.1 is the address of our DNS server.

  2. Test that the DNS servers listed in /etc/resolv.conf are able to resolve host names to the IP addresses of all masters and nodes in your OpenShift Container Platform environment:

    $ dig <node_hostname> @<IP_address> +short

    For example:

    $ dig master.example.com @10.64.33.1 +short
    10.64.33.100
    $ dig node1.example.com @10.64.33.1 +short
    10.64.33.101
2.2.2.1.2. Configuring a DNS Wildcard

Optionally, configure a wildcard for the router to use, so that you do not need to update your DNS configuration when new routes are added.

A wildcard for a DNS zone must ultimately resolve to the IP address of the OpenShift Container Platform router.

For example, create a wildcard DNS entry for cloudapps that has a low time-to-live value (TTL) and points to the public IP address of the host where the router will be deployed:

*.cloudapps.example.com. 300 IN  A 192.168.133.2

In almost all cases, when referencing VMs you must use host names, and the host names that you use must match the output of the hostname -f command on each node.

Warning

In your /etc/resolv.conf file on each node host, ensure that the DNS server that has the wildcard entry is not listed as a nameserver or that the wildcard domain is not listed in the search list. Otherwise, containers managed by OpenShift Container Platform may fail to resolve host names properly.

2.2.2.2. Network Access

A shared network must exist between the master and node hosts. If you plan to configure multiple masters for high-availability using the advanced installation method, you must also select an IP to be configured as your virtual IP (VIP) during the installation process. The IP that you select must be routable between all of your nodes, and if you configure using a FQDN it should resolve on all nodes.

2.2.2.2.1. NetworkManager

NetworkManager, a program for providing detection and configuration for systems to automatically connect to the network, is required.

2.2.2.2.2. Required Ports

The OpenShift Container Platform installation automatically creates a set of internal firewall rules on each host using iptables. However, if your network configuration uses an external firewall, such as a hardware-based firewall, you must ensure infrastructure components can communicate with each other through specific ports that act as communication endpoints for certain processes or services.

Ensure the following ports required by OpenShift Container Platform are open on your network and configured to allow access between hosts. Some ports are optional depending on your configuration and usage.

Table 2.1. Node to Node

4789

UDP

Required for SDN communication between pods on separate hosts.

Table 2.2. Nodes to Master

53 or 8053

TCP/UDP

Required for DNS resolution of cluster services (SkyDNS). Installations prior to 3.2 or environments upgraded to 3.2 use port 53. New installations will use 8053 by default so that dnsmasq may be configured.

4789

UDP

Required for SDN communication between pods on separate hosts.

443 or 8443

TCP

Required for node hosts to communicate to the master API, for the node hosts to post back status, to receive tasks, and so on.

Table 2.3. Master to Node

4789

UDP

Required for SDN communication between pods on separate hosts.

10250

TCP

The master proxies to node hosts via the Kubelet for oc commands.

Note

In the following table, (L) indicates the marked port is also used in loopback mode, enabling the master to communicate with itself.

In a single-master cluster:

  • Ports marked with (L) must be open.
  • Ports not marked with (L) need not be open.

In a multiple-master cluster, all the listed ports must be open.

Table 2.4. Master to Master

53 (L) or 8053 (L)

TCP/UDP

Required for DNS resolution of cluster services (SkyDNS). Installations prior to 3.2 or environments upgraded to 3.2 use port 53. New installations will use 8053 by default so that dnsmasq may be configured.

2049 (L)

TCP/UDP

Required when provisioning an NFS host as part of the installer.

2379

TCP

Used for standalone etcd (clustered) to accept changes in state.

2380

TCP

etcd requires this port be open between masters for leader election and peering connections when using standalone etcd (clustered).

4001 (L)

TCP

Used for embedded etcd (non-clustered) to accept changes in state.

4789 (L)

UDP

Required for SDN communication between pods on separate hosts.

Table 2.5. External to Load Balancer

9000

TCP

If you choose the native HA method, optional to allow access to the HAProxy statistics page.

Table 2.6. External to Master

443 or 8443

TCP

Required for node hosts to communicate to the master API, for node hosts to post back status, to receive tasks, and so on.

Table 2.7. IaaS Deployments

22

TCP

Required for SSH by the installer or system administrator.

53 or 8053

TCP/UDP

Required for DNS resolution of cluster services (SkyDNS). Installations prior to 3.2 or environments upgraded to 3.2 use port 53. New installations will use 8053 by default so that dnsmasq may be configured. Only required to be internally open on master hosts.

80 or 443

TCP

For HTTP/HTTPS use for the router. Required to be externally open on node hosts, especially on nodes running the router.

1936

TCP

For router statistics use. Required to be open when running the template router to access statistics, and can be open externally or internally to connections depending on if you want the statistics to be expressed publicly.

4001

TCP

For embedded etcd (non-clustered) use. Only required to be internally open on the master host. 4001 is for server-client connections.

2379 and 2380

TCP

For standalone etcd use. Only required to be internally open on the master host. 2379 is for server-client connections. 2380 is for server-server connections, and is only required if you have clustered etcd.

4789

UDP

For VxLAN use (OpenShift SDN). Required only internally on node hosts.

8443

TCP

For use by the OpenShift Container Platform web console, shared with the API server.

10250

TCP

For use by the Kubelet. Required to be externally open on nodes.

Notes

  • In the above examples, port 4789 is used for User Datagram Protocol (UDP).
  • When deployments are using the SDN, the pod network is accessed via a service proxy, unless it is accessing the registry from the same node the registry is deployed on.
  • OpenShift Container Platform internal DNS cannot be received over SDN. Depending on the detected values of openshift_facts, or if the openshift_ip and openshift_public_ip values are overridden, it will be the computed value of openshift_ip. For non-cloud deployments, this will default to the IP address associated with the default route on the master host. For cloud deployments, it will default to the IP address associated with the first internal interface as defined by the cloud metadata.
  • The master host uses port 10250 to reach the nodes and does not go over SDN. It depends on the target host of the deployment and uses the computed values of openshift_hostname and openshift_public_hostname.

Table 2.8. Aggregated Logging

9200

TCP

For Elasticsearch API use. Required to be internally open on any infrastructure nodes so Kibana is able to retrieve logs for display. It can be externally opened for direct access to Elasticsearch by means of a route. The route can be created using oc expose.

9300

TCP

For Elasticsearch inter-cluster use. Required to be internally open on any infrastructure node so the members of the Elasticsearch cluster may communicate with each other.

2.2.2.3. Persistent Storage

The Kubernetes persistent volume framework allows you to provision an OpenShift Container Platform cluster with persistent storage using networked storage available in your environment. This can be done after completing the initial OpenShift Container Platform installation depending on your application needs, giving users a way to request those resources without having any knowledge of the underlying infrastructure.

The Installation and Configuration Guide provides instructions for cluster administrators on provisioning an OpenShift Container Platform cluster with persistent storage using NFS, GlusterFS, Ceph RBD, OpenStack Cinder, AWS Elastic Block Store (EBS), GCE Persistent Disks, and iSCSI.

2.2.2.4. Cloud Provider Considerations

There are certain aspects to take into consideration if installing OpenShift Container Platform on a cloud provider.

2.2.2.4.1. Configuring a Security Group

When installing on AWS or OpenStack, ensure that you set up the appropriate security groups. These are some ports that you should have in your security groups, without which the installation will fail. You may need more depending on the cluster configuration you want to install. For more information and to adjust your security groups accordingly, see Required Ports for more information.

All OpenShift Container Platform Hosts

  • tcp/22 from host running the installer/Ansible

etcd Security Group

  • tcp/2379 from masters
  • tcp/2380 from etcd hosts

Master Security Group

  • tcp/8443 from 0.0.0.0/0
  • tcp/53 from all OpenShift Container Platform hosts for environments installed prior to or upgraded to 3.2
  • udp/53 from all OpenShift Container Platform hosts for environments installed prior to or upgraded to 3.2
  • tcp/8053 from all OpenShift Container Platform hosts for new environments installed with 3.2
  • udp/8053 from all OpenShift Container Platform hosts for new environments installed with 3.2

Node Security Group

  • tcp/10250 from masters
  • udp/4789 from nodes

Infrastructure Nodes (ones that can host the OpenShift Container Platform router)

  • tcp/443 from 0.0.0.0/0
  • tcp/80 from 0.0.0.0/0

If configuring ELBs for load balancing the masters and/or routers, you also need to configure Ingress and Egress security groups for the ELBs appropriately.

2.2.2.4.2. Overriding Detected IP Addresses and Host Names

Some deployments require that the user override the detected host names and IP addresses for the hosts. To see the default values, run the openshift_facts playbook:

# ansible-playbook  [-i /path/to/inventory] \
    /usr/share/ansible/openshift-ansible/roles/openshift_facts/library/openshift_facts.py

Now, verify the detected common settings. If they are not what you expect them to be, you can override them.

The Advanced Installation topic discusses the available Ansible variables in greater detail.

VariableUsage

hostname

  • Should resolve to the internal IP from the instances themselves.
  • openshift_hostname overrides.

ip

  • Should be the internal IP of the instance.
  • openshift_ip will overrides.

public_hostname

  • Should resolve to the external IP from hosts outside of the cloud.
  • Provider openshift_public_hostname overrides.

public_ip

  • Should be the externally accessible IP associated with the instance.
  • openshift_public_ip overrides.

use_openshift_sdn

  • Should be true unless the cloud is GCE.
  • openshift_use_openshift_sdn overrides.
Warning

If openshift_hostname is set to a value other than the metadata-provided private-dns-name value, the native cloud integration for those providers will no longer work.

In AWS, situations that require overriding the variables include:

VariableUsage

hostname

The user is installing in a VPC that is not configured for both DNS hostnames and DNS resolution.

ip

Possibly if they have multiple network interfaces configured and they want to use one other than the default. You must first set openshift_set_node_ip to True. Otherwise, the SDN would attempt to use the hostname setting or try to resolve the host name for the IP.

public_hostname

  • A master instance where the VPC subnet is not configured for Auto-assign Public IP. For external access to this master, you need to have an ELB or other load balancer configured that would provide the external access needed, or you need to connect over a VPN connection to the internal name of the host.
  • A master instance where metadata is disabled.
  • This value is not actually used by the nodes.

public_ip

  • A master instance where the VPC subnet is not configured for Auto-assign Public IP.
  • A master instance where metadata is disabled.
  • This value is not actually used by the nodes.

If setting openshift_hostname to something other than the metadata-provided private-dns-name value, the native cloud integration for those providers will no longer work.

For EC2 hosts in particular, they must be deployed in a VPC that has both DNS host names and DNS resolution enabled, and openshift_hostname should not be overridden.

2.2.2.4.3. Post-Installation Configuration for Cloud Providers

Following the installation process, you can configure OpenShift Container Platform for AWS, OpenStack, or GCE.

2.2.2.5. Containerized GlusterFS Considerations

If you choose to configure containerized GlusterFS persistent storage for your cluster, or if you choose to configure a containerized GlusterFS-backed OpenShift Container Registry, you must consider the following prerequisites.

2.2.2.5.1. Storage Nodes

To use containerized GlusterFS persistent storage:

  • A minimum of 3 storage nodes is required.
  • Each storage node must have at least 1 raw block device with least 100 GB available.

To run a containerized GlusterFS-backed OpenShift Container Registry:

  • A minimum of 3 storage nodes is required.
  • Each storage node must have at least 1 raw block device with at least 10 GB of free storage.
Important

While containerized GlusterFS persistent storage can be configured and deployed on the same OpenShift Container Platform cluster as a containerized GlusterFS-backed registry, their storage should be kept separate from each other and also requires additional storage nodes. For example, if both are configured, a total of 6 storage nodes would be needed: 3 for the registry and 3 for persistent storage. This limitation is imposed to avoid potential impacts on performance in I/O and volume creation.

2.2.2.5.2. Required Software Components

For any RHEL (non-Atomic) storage nodes, the following RPM respository must be enabled:

# subscription-manager repos --enable=rh-gluster-3-client-for-rhel-7-server-rpms

The mount.glusterfs command must be available on all nodes that will host pods that will use GlusterFS volumes. For RPM-based systems, the glusterfs-fuse package must be installed:

# yum install glusterfs-fuse

If GlusterFS is already installed on the nodes, ensure the latest version is installed:

# yum update glusterfs-fuse

2.3. Host Preparation

2.3.1. Operating System Requirements

A base installation of RHEL 7.3 or 7.4 (with the latest packages from the Extras channel) or RHEL Atomic Host 7.4.2 or later is required for master and node hosts. See the following documentation for the respective installation instructions, if required:

2.3.2. Host Registration

Each host must be registered using Red Hat Subscription Manager (RHSM) and have an active OpenShift Container Platform subscription attached to access the required packages.

  1. On each host, register with RHSM:

    # subscription-manager register --username=<user_name> --password=<password>
  2. Pull the latest subscription data from RHSM:

    # subscription-manager refresh
  3. List the available subscriptions:

    # subscription-manager list --available --matches '*OpenShift*'
  4. In the output for the previous command, find the pool ID for an OpenShift Container Platform subscription and attach it:

    # subscription-manager attach --pool=<pool_id>
  5. Disable all yum repositories:

    1. Disable all the enabled RHSM repositories:

      # subscription-manager repos --disable="*"
    2. List the remaining yum repositories and note their names under repo id, if any:

      # yum repolist
    3. Use yum-config-manager to disable the remaining yum repositories:

      # yum-config-manager --disable <repo_id>

      Alternatively, disable all repositories:

       yum-config-manager --disable \*

      Note that this could take a few minutes if you have a large number of available repositories

  6. Enable only the repositories required by OpenShift Container Platform 3.7:

    # subscription-manager repos \
        --enable="rhel-7-server-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-server-ose-3.7-rpms" \
        --enable="rhel-7-fast-datapath-rpms"

2.3.3. Installing Base Packages

For RHEL 7 systems:

  1. Install the following base packages:

    # yum install wget git net-tools bind-utils iptables-services bridge-utils bash-completion kexec-tools sos psacct
  2. Update the system to the latest packages:

    # yum update
  3. If you plan to use the RPM-based installer to run an advanced installation, you can skip this step. However, if you plan to use the containerized installer (currently a Technology Preview feature):

    1. Install the atomic package:

      # yum install atomic
    2. Skip to Installing Docker.
  4. Install the following package, which provides RPM-based OpenShift Container Platform installer utilities and pulls in other tools required by the quick and advanced installation methods, such as Ansible and related configuration files:

    # yum install atomic-openshift-utils

For RHEL Atomic Host 7 systems:

  1. Ensure the host is up to date by upgrading to the latest Atomic tree if one is available:

    # atomic host upgrade
  2. After the upgrade is completed and prepared for the next boot, reboot the host:

    # systemctl reboot

2.3.4. Installing Docker

At this point, you should install Docker on all master and node hosts. This allows you to configure your Docker storage options before installing OpenShift Container Platform.

For RHEL 7 systems, install Docker 1.12:

Note

On RHEL Atomic Host 7 systems, Docker should already be installed, configured, and running by default.

# yum install docker-1.12.6

After the package installation is complete, verify that version 1.12 was installed:

# rpm -V docker-1.12.6
# docker version
Note

The Advanced Installation method automatically changes /etc/sysconfig/docker.

The --insecure-registry option instructs the Docker daemon to trust any Docker registry on the indicated subnet, rather than requiring a certificate.

Important

172.30.0.0/16 is the default value of the servicesSubnet variable in the master-config.yaml file. If this has changed, then the --insecure-registry value in the above step should be adjusted to match, as it is indicating the subnet for the registry to use. Note that the openshift_master_portal_net variable can be set in the Ansible inventory file and used during the advanced installation method to modify the servicesSubnet variable.

Note

After the initial OpenShift Container Platform installation is complete, you can choose to secure the integrated Docker registry, which involves adjusting the --insecure-registry option accordingly.

2.3.5. Configuring Docker Storage

Containers and the images they are created from are stored in Docker’s storage back end. This storage is ephemeral and separate from any persistent storage allocated to meet the needs of your applications.

For RHEL Atomic Host

The default storage back end for Docker on RHEL Atomic Host is a thin pool logical volume, which is supported for production environments. You must ensure that enough space is allocated for this volume per the Docker storage requirements mentioned in System Requirements.

If you do not have enough allocated, see Managing Storage with Docker Formatted Containers for details on using docker-storage-setup and basic instructions on storage management in RHEL Atomic Host.

For RHEL

The default storage back end for Docker on RHEL 7 is a thin pool on loopback devices, which is not supported for production use and only appropriate for proof of concept environments. For production environments, you must create a thin pool logical volume and re-configure Docker to use that volume.

You can use the docker-storage-setup script included with Docker to create a thin pool device and configure Docker’s storage driver. This can be done after installing Docker and should be done before creating images or containers. The script reads configuration options from the /etc/sysconfig/docker-storage-setup file and supports three options for creating the logical volume:

  • Option A) Use an additional block device.
  • Option B) Use an existing, specified volume group.
  • Option C) Use the remaining free space from the volume group where your root file system is located.

Option A is the most robust option, however it requires adding an additional block device to your host before configuring Docker storage. Options B and C both require leaving free space available when provisioning your host. Option C is known to cause issues with some applications, for example Red Hat Mobile Application Platform (RHMAP).

  1. Create the docker-pool volume using one of the following three options:

    • Option A) Use an additional block device.

      In /etc/sysconfig/docker-storage-setup, set DEVS to the path of the block device you wish to use. Set VG to the volume group name you wish to create; docker-vg is a reasonable choice. For example:

      # cat <<EOF > /etc/sysconfig/docker-storage-setup
      DEVS=/dev/vdc
      VG=docker-vg
      EOF

      Then run docker-storage-setup and review the output to ensure the docker-pool volume was created:

      # docker-storage-setup                                                                                                                                                                                                                                [5/1868]
      0
      Checking that no-one is using this disk right now ...
      OK
      
      Disk /dev/vdc: 31207 cylinders, 16 heads, 63 sectors/track
      sfdisk:  /dev/vdc: unrecognized partition table type
      
      Old situation:
      sfdisk: No partitions found
      
      New situation:
      Units: sectors of 512 bytes, counting from 0
      
         Device Boot    Start       End   #sectors  Id  System
      /dev/vdc1          2048  31457279   31455232  8e  Linux LVM
      /dev/vdc2             0         -          0   0  Empty
      /dev/vdc3             0         -          0   0  Empty
      /dev/vdc4             0         -          0   0  Empty
      Warning: partition 1 does not start at a cylinder boundary
      Warning: partition 1 does not end at a cylinder boundary
      Warning: no primary partition is marked bootable (active)
      This does not matter for LILO, but the DOS MBR will not boot this disk.
      Successfully wrote the new partition table
      
      Re-reading the partition table ...
      
      If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
      to zero the first 512 bytes:  dd if=/dev/zero of=/dev/foo7 bs=512 count=1
      (See fdisk(8).)
        Physical volume "/dev/vdc1" successfully created
        Volume group "docker-vg" successfully created
        Rounding up size to full physical extent 16.00 MiB
        Logical volume "docker-poolmeta" created.
        Logical volume "docker-pool" created.
        WARNING: Converting logical volume docker-vg/docker-pool and docker-vg/docker-poolmeta to pool's data and metadata volumes.
        THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.)
        Converted docker-vg/docker-pool to thin pool.
        Logical volume "docker-pool" changed.
    • Option B) Use an existing, specified volume group.

      In /etc/sysconfig/docker-storage-setup, set VG to the desired volume group. For example:

      # cat <<EOF > /etc/sysconfig/docker-storage-setup
      VG=docker-vg
      EOF

      Then run docker-storage-setup and review the output to ensure the docker-pool volume was created:

      # docker-storage-setup
        Rounding up size to full physical extent 16.00 MiB
        Logical volume "docker-poolmeta" created.
        Logical volume "docker-pool" created.
        WARNING: Converting logical volume docker-vg/docker-pool and docker-vg/docker-poolmeta to pool's data and metadata volumes.
        THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.)
        Converted docker-vg/docker-pool to thin pool.
        Logical volume "docker-pool" changed.
    • Option C) Use the remaining free space from the volume group where your root file system is located.

      Verify that the volume group where your root file system resides has the desired free space, then run docker-storage-setup and review the output to ensure the docker-pool volume was created:

      # docker-storage-setup
        Rounding up size to full physical extent 32.00 MiB
        Logical volume "docker-poolmeta" created.
        Logical volume "docker-pool" created.
        WARNING: Converting logical volume rhel/docker-pool and rhel/docker-poolmeta to pool's data and metadata volumes.
        THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.)
        Converted rhel/docker-pool to thin pool.
        Logical volume "docker-pool" changed.
  2. Verify your configuration. You should have a dm.thinpooldev value in the /etc/sysconfig/docker-storage file and a docker-pool logical volume:

    # cat /etc/sysconfig/docker-storage
    DOCKER_STORAGE_OPTIONS=--storage-opt dm.fs=xfs --storage-opt
    dm.thinpooldev=/dev/mapper/docker--vg-docker--pool
    
    # lvs
      LV          VG   Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
      docker-pool rhel twi-a-t---  9.29g             0.00   0.12
    Important

    Before using Docker or OpenShift Container Platform, verify that the docker-pool logical volume is large enough to meet your needs. The docker-pool volume should be 60% of the available volume group and will grow to fill the volume group via LVM monitoring.

  3. Check if Docker is running:

    # systemctl is-active docker
  4. If Docker has not yet been started on the host, enable and start the service:

    # systemctl enable docker
    # systemctl start docker

    If Docker is already running, re-initialize Docker:

    Warning

    This will destroy any containers or images currently on the host.

    # systemctl stop docker
    # rm -rf /var/lib/docker/*
    # systemctl restart docker

    If there is any content in /var/lib/docker/, it must be deleted. Files will be present if Docker has been used prior to the installation of OpenShift Container Platform.

2.3.5.1. Reconfiguring Docker Storage

Should you need to reconfigure Docker storage after having created the docker-pool, you should first remove the docker-pool logical volume. If you are using a dedicated volume group, you should also remove the volume group and any associated physical volumes before reconfiguring docker-storage-setup according to the instructions above.

See Logical Volume Manager Administration for more detailed information on LVM management.

2.3.5.2. Enabling Image Signature Support

OpenShift Container Platform is capable of cryptographically verifying images are from trusted sources. The Container Security Guide provides a high-level description of how image signing works.

You can configure image signature verification using the atomic command line interface (CLI), version 1.12.5 or greater. The atomic CLI is pre-installed on RHEL Atomic Host systems.

Note

For more on the atomic CLI, see the Atomic CLI documentation.

Install the atomic package if it is not installed on the host system:

$ yum install atomic

The atomic trust sub-command manages trust configuration. The default configuration is to whitelist all registries. This means no signature verification is configured.

$ atomic trust show
* (default)                         accept

A reasonable configuration might be to whitelist a particular registry or namespace, blacklist (reject) untrusted registries, and require signature verification on a vendor registry. The following set of commands performs this example configuration:

Example Atomic Trust Configuration

$ atomic trust add --type insecureAcceptAnything 172.30.1.1:5000

$ atomic trust add --sigstoretype atomic \
  --pubkeys pub@example.com \
  172.30.1.1:5000/production

$ atomic trust add --sigstoretype atomic \
  --pubkeys /etc/pki/example.com.pub \
  172.30.1.1:5000/production

$ atomic trust add --sigstoretype web \
  --sigstore https://access.redhat.com/webassets/docker/content/sigstore \
  --pubkeys /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release \
  registry.access.redhat.com

$ sudo atomic trust show
* (default)                         accept
172.30.1.1:5000                     accept
172.30.1.1:5000/production          signed security@example.com
registry.access.redhat.com          signed security@redhat.com,security@redhat.com

When all the signed sources are verified, nodes may be further hardened with a global reject default:

$ atomic trust default reject

$ atomic trust show
* (default)                         reject
172.30.1.1:5000                     accept
172.30.1.1:5000/production          signed security@example.com
registry.access.redhat.com          signed security@redhat.com,security@redhat.com

Use the atomic man page man atomic-trust for additional examples.

The following files and directories comprise the trust configuration of a host:

  • /etc/containers/registries.d/*
  • /etc/containers/policy.json

The trust configuration may be managed directly on each node or the generated files managed on a separate host and distributed to the appropriate nodes using Ansible, for example. See this Red Hat Knowledgebase Article for an example of automating file distribution with Ansible.

2.3.5.3. Managing Container Logs

Sometimes a container’s log file (the /var/lib/docker/containers/<hash>/<hash>-json.log file on the node where the container is running) can increase to a problematic size. You can manage this by configuring Docker’s json-file logging driver to restrict the size and number of log files.

Important

Aggregated logging is only supported using the journald driver in Docker. See Updating Fluentd’s Log Source After a Docker Log Driver Update for more information.

OptionPurpose

--log-opt max-size

Sets the size at which a new log file is created.

--log-opt max-file

Sets the file on each host to configure the options.

For example, to set the maximum file size to 1MB and always keep the last three log files, edit the /etc/sysconfig/docker file to configure max-size=1M and max-file=3:

OPTIONS='--insecure-registry=172.30.0.0/16 --selinux-enabled --log-opt max-size=1M --log-opt max-file=3'

Next, restart the Docker service:

# systemctl restart docker

2.3.5.4. Viewing Available Container Logs

Container logs are stored in the /var/lib/docker/containers/<hash>/ directory on the node where the container is running. For example:

# ls -lh /var/lib/docker/containers/f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8/
total 2.6M
-rw-r--r--. 1 root root 5.6K Nov 24 00:12 config.json
-rw-r--r--. 1 root root 649K Nov 24 00:15 f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8-json.log
-rw-r--r--. 1 root root 977K Nov 24 00:15 f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8-json.log.1
-rw-r--r--. 1 root root 977K Nov 24 00:15 f088349cceac173305d3e2c2e4790051799efe363842fdab5732f51f5b001fd8-json.log.2
-rw-r--r--. 1 root root 1.3K Nov 24 00:12 hostconfig.json
drwx------. 2 root root    6 Nov 24 00:12 secrets

See Docker’s documentation for additional information on how to Configure Logging Drivers.

2.3.6. Ensuring Host Access

The quick and advanced installation methods require a user that has access to all hosts. If you want to run the installer as a non-root user, passwordless sudo rights must be configured on each destination host.

For example, you can generate an SSH key on the host where you will invoke the installation process:

# ssh-keygen

Do not use a password.

An easy way to distribute your SSH keys is by using a bash loop:

# for host in master.example.com \
    node1.example.com \
    node2.example.com; \
    do ssh-copy-id -i ~/.ssh/id_rsa.pub $host; \
    done

Modify the host names in the above command according to your configuration.

2.3.7. What’s Next?

If you are interested in installing OpenShift Container Platform using the containerized method (optional for RHEL but required for RHEL Atomic Host), see Installing on Containerized Hosts to prepare your hosts.

When you are ready to proceed, you can install OpenShift Container Platform using the quick installation or advanced installation method.

If you are installing a stand-alone registry, continue with Installing a Stand-alone Registry.

2.4. Installing on Containerized Hosts

2.4.1. Overview

An RPM installation installs all services through package management and configures services to run within the same user space, while a containerized installation installs services using container images and runs separate services in individual containers.

The default method for installing OpenShift Container Platform on Red Hat Enterprise Linux (RHEL) uses RPMs.

Important

When targeting a Red Hat Atomic Host system, the containerized method is the only available option, and is automatically selected for you based on the detection of the /run/ostree-booted file.

The following table outlines the differences between the RPM and Containerized methods:

 RPMContainerized

Installation Method

Packages via yum

Container images via docker

Service Management

systemd

docker and systemd units

Operating System

Red Hat Enterprise Linux

Red Hat Enterprise Linux or Red Hat Atomic Host

2.4.2. Install Methods for Containerized Hosts

As with the RPM installation, you can choose between the quick and advanced install methods for the containerized install.

For the quick installation method, you can choose between the RPM or containerized method on a per host basis during the interactive installation, or set the values manually in an installation configuration file.

For the advanced installation method, you can set the Ansible variable containerized=true in an inventory file on a cluster-wide or per host basis.

For the disconnected installation method, to install the etcd container, you can set the Ansible variable osm_etcd_image to be the fully qualified name of the etcd image on your local registry, for example, registry.example.com/rhel7/etcd.

2.4.3. Required Images

Containerized installations make use of the following images:

  • openshift3/ose
  • openshift3/node
  • openshift3/openvswitch
  • registry.access.redhat.com/rhel7/etcd

By default, all of the above images are pulled from the Red Hat Registry at registry.access.redhat.com.

If you need to use a private registry to pull these images during the installation, you can specify the registry information ahead of time. For the advanced installation method, you can set the following Ansible variables in your inventory file, as required:

openshift_docker_additional_registries=<registry_hostname>
openshift_docker_insecure_registries=<registry_hostname>
openshift_docker_blocked_registries=<registry_hostname>

For the quick installation method, you can export the following environment variables on each target host:

# export OO_INSTALL_ADDITIONAL_REGISTRIES=<registry_hostname>
# export OO_INSTALL_INSECURE_REGISTRIES=<registry_hostname>

Blocked Docker registries cannot currently be specified using the quick installation method.

The configuration of additional, insecure, and blocked Docker registries occurs at the beginning of the installation process to ensure that these settings are applied before attempting to pull any of the required images.

2.4.4. CLI Wrappers

When using containerized installations, a CLI wrapper script is deployed on each master at /usr/local/bin/openshift. The following set of symbolic links are also provided to ease administrative tasks:

Symbolic LinkUsage

/usr/local/bin/oc

Developer CLI

/usr/local/bin/oadm

Administrative CLI

/usr/local/bin/kubectl

Kubernetes CLI

The wrapper spawns a new container on each invocation, so you may notice it run slightly slower than native CLI operations.

The wrapper scripts mount a limited subset of paths:

  • ~/.kube
  • /etc/origin/
  • /tmp/

Be mindful of this when passing in files to be processed by the oc or oadm commands. You may find it easier to redirect the input, for example:

# oc create -f - < my-file.json
Note

The wrapper is intended only to be used to bootstrap an environment. You should install the CLI tools on another host after you have granted cluster-admin privileges to a user. See Managing Role Bindings and Get Started with the CLI for more information.

2.4.5. Starting and Stopping Containers

The installation process creates relevant systemd units which can be used to start, stop, and poll services using normal systemctl commands. For containerized installations, these unit names match those of an RPM installation, with the exception of the etcd service which is named etcd_container.

This change is necessary as currently RHEL Atomic Host ships with the etcd package installed as part of the operating system, so a containerized version is used for the OpenShift Container Platform installation instead. The installation process disables the default etcd service. The etcd package is slated to be removed from RHEL Atomic Host in the future.

2.4.6. File Paths

All OpenShift Container Platform configuration files are placed in the same locations during containerized installation as RPM based installations and will survive os-tree upgrades.

However, the default image stream and template files are installed at /etc/origin/examples/ for containerized installations rather than the standard /usr/share/openshift/examples/, because that directory is read-only on RHEL Atomic Host.

2.4.7. Storage Requirements

RHEL Atomic Host installations normally have a very small root file system. However, the etcd, master, and node containers persist data in the /var/lib/ directory. Ensure that you have enough space on the root file system before installing OpenShift Container Platform. See the System Requirements section for details.

2.4.8. Open vSwitch SDN Initialization

OpenShift SDN initialization requires that the Docker bridge be reconfigured and that Docker is restarted. This complicates the situation when the node is running within a container. When using the Open vSwitch (OVS) SDN, you will see the node start, reconfigure Docker, restart Docker (which restarts all containers), and finally start successfully.

In this case, the node service may fail to start and be restarted a few times, because the master services are also restarted along with Docker. The current implementation uses a workaround which relies on setting the Restart=always parameter in the Docker based systemd units.

2.5. Quick Installation

2.5.1. Overview

The quick installation method allows you to use an interactive CLI utility, the atomic-openshift-installer command, to install OpenShift Container Platform across a set of hosts. This installer can deploy OpenShift Container Platform components on targeted hosts by either installing RPMs or running containerized services.

Important

While RHEL Atomic Host is supported for running containerized OpenShift Container Platform services, the installer is provided by an RPM and not available by default in RHEL Atomic Host. Therefore, it must be run from a Red Hat Enterprise Linux 7 system. The host initiating the installation does not need to be intended for inclusion in the OpenShift Container Platform cluster, but it can be.

This installation method is provided to make the installation experience easier by interactively gathering the data needed to run on each host. The installer is a self-contained wrapper intended for usage on a Red Hat Enterprise Linux (RHEL) 7 system.

In addition to running interactive installations from scratch, the atomic-openshift-installer command can also be run or re-run using a predefined installation configuration file. This file can be used with the installer to:

Alternatively, you can use the advanced installation method for more complex environments.

Note

To install OpenShift Container Platform as a stand-alone registry, see Installing a Stand-alone Registry.

2.5.2. Before You Begin

The installer allows you to install OpenShift Container Platform master and node components on a defined set of hosts.

Note

By default, any hosts you designate as masters during the installation process are automatically also configured as nodes so that the masters are configured as part of the OpenShift Container Platform SDN. The node component on the masters, however, are marked unschedulable, which blocks pods from being scheduled on it. After the installation, you can mark them schedulable if you want.

Before installing OpenShift Container Platform, you must first satisfy the prerequisites on your hosts, which includes verifying system and environment requirements and properly installing and configuring Docker. You must also be prepared to provide or validate the following information for each of your targeted hosts during the course of the installation:

  • User name on the target host that should run the Ansible-based installation (can be root or non-root)
  • Host name
  • Whether to install components for master, node, or both
  • Whether to use the RPM or containerized method
  • Internal and external IP addresses
Important

If you are installing OpenShift Container Platform using the containerized method (optional for RHEL but required for RHEL Atomic Host), see the Installing on Containerized Hosts topic to ensure that you understand the differences between these methods, then return to this topic to continue.

After following the instructions in the Prerequisites topic and deciding between the RPM and containerized methods, you can continue to running an interactive or unattended installation.

2.5.3. Running an Interactive Installation

Note

Ensure you have read through Before You Begin.

You can start the interactive installation by running:

$ atomic-openshift-installer install

Then follow the on-screen instructions to install a new OpenShift Container Platform cluster.

After it has finished, ensure that you back up the ~/.config/openshift/installer.cfg.ymlinstallation configuration file that is created, as it is required if you later want to re-run the installation, add hosts to the cluster, or upgrade your cluster. Then, verify the installation.

2.5.4. Defining an Installation Configuration File

The installer can use a predefined installation configuration file, which contains information about your installation, individual hosts, and cluster. When running an interactive installation, an installation configuration file based on your answers is created for you in ~/.config/openshift/installer.cfg.yml. The file is created if you are instructed to exit the installation to manually modify the configuration or when the installation completes. You can also create the configuration file manually from scratch to perform an unattended installation.

Installation Configuration File Specification

version: v2 1
variant: openshift-enterprise 2
variant_version: 3.7 3
ansible_log_path: /tmp/ansible.log 4
deployment:
  ansible_ssh_user: root 5
  hosts: 6
  - ip: 10.0.0.1 7
    hostname: master-private.example.com 8
    public_ip: 24.222.0.1 9
    public_hostname: master.example.com 10
    roles: 11
      - master
      - node
    containerized: true 12
    connect_to: 24.222.0.1 13
  - ip: 10.0.0.2
    hostname: node1-private.example.com
    public_ip: 24.222.0.2
    public_hostname: node1.example.com
    node_labels: {'region': 'infra'} 14
    roles:
      - node
    connect_to: 10.0.0.2
  - ip: 10.0.0.3
    hostname: node2-private.example.com
    public_ip: 24.222.0.3
    public_hostname: node2.example.com
    roles:
      - node
    connect_to: 10.0.0.3
  roles: 15
    master:
      <variable_name1>: "<value1>" 16
      <variable_name2>: "<value2>"
    node:
      <variable_name1>: "<value1>" 17

1
The version of this installation configuration file. As of OpenShift Container Platform 3.3, the only valid version here is v2.
2
The OpenShift Container Platform variant to install. For OpenShift Container Platform, set this to openshift-enterprise.
3
A valid version of your selected variant: 3.7, 3.6, 3.5, 3.4, 3.3, 3.2, or 3.1. If not specified, this defaults to the latest version for the specified variant.
4
Defines where the Ansible logs are stored. By default, this is the /tmp/ansible.log file.
5
Defines which user Ansible uses to SSH in to remote systems for gathering facts and for the installation. By default, this is the root user, but you can set it to any user that has sudo privileges.
6
Defines a list of the hosts onto which you want to install the OpenShift Container Platform master and node components.
7 8
Required. Allows the installer to connect to the system and gather facts before proceeding with the install.
9 10
Required for unattended installations. If these details are not specified, then this information is pulled from the facts gathered by the installer, and you are asked to confirm the details. If undefined for an unattended installation, the installation fails.
11
Determines the type of services that are installed. Specified as a list.
12
If set to true, containerized OpenShift Container Platform services are run on target master and node hosts instead of installed using RPM packages. If set to false or unset, the default RPM method is used. RHEL Atomic Host requires the containerized method, and is automatically selected for you based on the detection of the /run/ostree-booted file. See Installing on Containerized Hosts for more details.
13
The IP address that Ansible attempts to connect to when installing, upgrading, or uninstalling the systems. If the configuration file was auto-generated, then this is the value you first enter for the host during that interactive install process.
14
Node labels can optionally be set per-host.
15
Defines a dictionary of roles across the deployment.
16 17
Any ansible variables that should only be applied to hosts assigned a role can be defined. For examples, see Configuring Ansible.

2.5.5. Running an Unattended Installation

Note

Ensure you have read through the Before You Begin.

Unattended installations allow you to define your hosts and cluster configuration in an installation configuration file before running the installer so that you do not have to go through all of the interactive installation questions and answers. It also allows you to resume an interactive installation you may have left unfinished, and quickly get back to where you left off.

To run an unattended installation, first define an installation configuration file at ~/.config/openshift/installer.cfg.yml. Then, run the installer with the -u flag:

$ atomic-openshift-installer -u install

By default in interactive or unattended mode, the installer uses the configuration file located at ~/.config/openshift/installer.cfg.yml if the file exists. If it does not exist, attempting to start an unattended installation fails.

Alternatively, you can specify a different location for the configuration file using the -c option, but doing so will require you to specify the file location every time you run the installation:

$ atomic-openshift-installer -u -c </path/to/file> install

After the unattended installation finishes, ensure that you back up the ~/.config/openshift/installer.cfg.yml file that was used, as it is required if you later want to re-run the installation, add hosts to the cluster, or upgrade your cluster. Then, verify the installation.

2.5.6. Verifying the Installation

  1. Verify that the master is started and nodes are registered and reporting in Ready status. On the master host, run the following as root:

    # oc get nodes
    
    NAME                        STATUS                     AGE
    master.example.com          Ready,SchedulingDisabled   165d
    node1.example.com           Ready                      165d
    node2.example.com           Ready                      165d
  2. To verify that the web console is installed correctly, use the master host name and the web console port number to access the web console with a web browser.

    For example, for a master host with a host name of master.openshift.com and using the default port of 8443, the web console would be found at https://master.openshift.com:8443/console.

  3. Then, see What’s Next for the next steps on configuring your OpenShift Container Platform cluster.

2.5.7. Uninstalling OpenShift Container Platform

You can uninstall OpenShift Container Platform from all hosts in your cluster using the installer’s uninstall command. By default, the installer uses the installation configuration file located at ~/.config/openshift/installer.cfg.yml if the file exists:

$ atomic-openshift-installer uninstall

Alternatively, you can specify a different location for the configuration file using the -c option:

$ atomic-openshift-installer -c </path/to/file> uninstall

See the advanced installation method for more options.

2.5.8. What’s Next?

Now that you have a working OpenShift Container Platform instance, you can:

2.6. Advanced Installation

2.6.1. Overview

A reference configuration implemented using Ansible playbooks is available as the advanced installation method for installing a OpenShift Container Platform cluster. Familiarity with Ansible is assumed, however you can use this configuration as a reference to create your own implementation using the configuration management tool of your choosing.

Important

While RHEL Atomic Host is supported for running containerized OpenShift Container Platform services, the advanced installation method utilizes Ansible, which is not available in RHEL Atomic Host, and must therefore be run from a RHEL 7 system. The host initiating the installation does not need to be intended for inclusion in the OpenShift Container Platform cluster, but it can be.

Alternatively, a containerized version of the installer is available as a system container, which is currently a Technology Preview feature.

Alternatively, you can use the quick installation method if you prefer an interactive installation experience.

Note

To install OpenShift Container Platform as a stand-alone registry, see Installing a Stand-alone Registry.

2.6.2. Before You Begin

Before installing OpenShift Container Platform, you must first see the Prerequisites and Host Preparation topics to prepare your hosts. This includes verifying system and environment requirements per component type and properly installing and configuring Docker. It also includes installing Ansible version 2.3 or later, as the advanced installation method is based on Ansible playbooks and as such requires directly invoking Ansible.

If you are interested in installing OpenShift Container Platform using the containerized method (optional for RHEL but required for RHEL Atomic Host), see Installing on Containerized Hosts to ensure that you understand the differences between these methods, then return to this topic to continue.

For large-scale installs, including suggestions for optimizing install time, see the Scaling and Performance Guide.

After following the instructions in the Prerequisites topic and deciding between the RPM and containerized methods, you can continue in this topic to Configuring Ansible Inventory Files.

2.6.3. Configuring Ansible Inventory Files

The /etc/ansible/hosts file is Ansible’s inventory file for the playbook used to install OpenShift Container Platform. The inventory file describes the configuration for your OpenShift Container Platform cluster. You must replace the default contents of the file with your desired configuration.

The following sections describe commonly-used variables to set in your inventory file during an advanced installation, followed by example inventory files you can use as a starting point for your installation.

Many of the Ansible variables described are optional. Accepting the default values should suffice for development environments, but for production environments it is recommended you read through and become familiar with the various options available.

The example inventories describe various environment topographies, including using multiple masters for high availability. You can choose an example that matches your requirements, modify it to match your own environment, and use it as your inventory file when running the advanced installation.

Image Version Policy

Images require a version number policy in order to maintain updates. See the Image Version Tag Policy section in the Architecture Guide for more information.

2.6.3.1. Configuring Cluster Variables

To assign environment variables during the Ansible install that apply more globally to your OpenShift Container Platform cluster overall, indicate the desired variables in the /etc/ansible/hosts file on separate, single lines within the [OSEv3:vars] section. For example:

[OSEv3:vars]

openshift_master_identity_providers=[{'name': 'htpasswd_auth',
'login': 'true', 'challenge': 'true',
'kind': 'HTPasswdPasswordIdentityProvider',
'filename': '/etc/origin/master/htpasswd'}]

openshift_master_default_subdomain=apps.test.example.com

The following table describes variables for use with the Ansible installer that can be assigned cluster-wide:

Table 2.9. Cluster Variables

VariablePurpose

ansible_ssh_user

This variable sets the SSH user for the installer to use and defaults to root. This user should allow SSH-based authentication without requiring a password. If using SSH key-based authentication, then the key should be managed by an SSH agent.

ansible_become

If ansible_ssh_user is not root, this variable must be set to true and the user must be configured for passwordless sudo.

debug_level

This variable sets which INFO messages are logged to the systemd-journald.service. Set one of the following:

  • 0 to log errors and warnings only
  • 2 to log normal information (This is the default level.)
  • 4 to log debugging-level information
  • 6 to log API-level debugging information (request / response)
  • 8 to log body-level API debugging information

For more information on debug log levels, see Configuring Logging Levels.

containerized

If set to true, containerized OpenShift Container Platform services are run on all target master and node hosts in the cluster instead of installed using RPM packages. If set to false or unset, the default RPM method is used. RHEL Atomic Host requires the containerized method, and is automatically selected for you based on the detection of the /run/ostree-booted file. See Installing on Containerized Hosts for more details. Containerized installations are supported starting in OpenShift Container Platform 3.1.1.

openshift_master_admission_plugin_config

This variable sets the parameter and arbitrary JSON values as per the requirement in your inventory hosts file.

openshift_master_audit_config

This variable enables API service auditing. See Audit Configuration for more information.

openshift_master_cluster_hostname

This variable overrides the host name for the cluster, which defaults to the host name of the master.

openshift_master_cluster_public_hostname

This variable overrides the public host name for the cluster, which defaults to the host name of the master.

openshift_master_cluster_method

Optional. This variable defines the HA method when deploying multiple masters. Supports the native method. See Multiple Masters for more information.

openshift_rolling_restart_mode

This variable enables rolling restarts of HA masters (i.e., masters are taken down one at a time) when running the upgrade playbook directly. It defaults to services, which allows rolling restarts of services on the masters. It can instead be set to system, which enables rolling, full system restarts and also works for single master clusters.

os_sdn_network_plugin_name

This variable configures which OpenShift SDN plug-in to use for the pod network, which defaults to redhat/openshift-ovs-subnet for the standard SDN plug-in. Set the variable to redhat/openshift-ovs-multitenant to use the multitenant plug-in.

openshift_master_identity_providers

This variable overrides the identity provider, which defaults to Deny All.

openshift_master_named_certificates

These variables are used to configure custom certificates which are deployed as part of the installation. See Configuring Custom Certificates for more information.

openshift_master_overwrite_named_certificates

openshift_hosted_registry_cert_expire_days

Validity of the auto-generated registry certificate in days. Defaults to 730 (2 years).

openshift_ca_cert_expire_days

Validity of the auto-generated CA certificate in days. Defaults to 1825 (5 years).

openshift_node_cert_expire_days

Validity of the auto-generated node certificate in days. Defaults to 730 (2 years).

openshift_master_cert_expire_days

Validity of the auto-generated master certificate in days. Defaults to 730 (2 years).

etcd_ca_default_days

Validity of the auto-generated external etcd certificates in days. Controls validity for etcd CA, peer, server and client certificates. Defaults to 1825 (5 years).

os_firewall_use_firewalld

Set to true to use firewalld instead of the default iptables. Not available on RHEL Atomic Host. See the Configuring the Firewall section for more information.

openshift_master_session_name

These variables override defaults for session options in the OAuth configuration. See Configuring Session Options for more information.

openshift_master_session_max_seconds

openshift_master_session_auth_secrets

openshift_master_session_encryption_secrets

openshift_portal_net

This variable configures the subnet in which services will be created within the OpenShift Container Platform SDN. This network block should be private and must not conflict with any existing network blocks in your infrastructure to which pods, nodes, or the master may require access to, or the installation will fail. Defaults to 172.30.0.0/16, and cannot be re-configured after deployment. If changing from the default, avoid 172.17.0.0/16, which the docker0 network bridge uses by default, or modify the docker0 network.

openshift_master_default_subdomain

This variable overrides the default subdomain to use for exposed routes.

openshift_node_proxy_mode

This variable specifies the service proxy mode to use: either iptables for the default, pure-iptables implementation, or userspace for the user space proxy.

osm_default_node_selector

This variable overrides the node selector that projects will use by default when placing pods.

osm_cluster_network_cidr

This variable overrides the SDN cluster network CIDR block. This is the network from which pod IPs are assigned. This network block should be a private block and must not conflict with existing network blocks in your infrastructure to which pods, nodes, or the master may require access. Defaults to 10.128.0.0/14 and cannot be arbitrarily re-configured after deployment, although certain changes to it can be made in the SDN master configuration.

osm_host_subnet_length

This variable specifies the size of the per host subnet allocated for pod IPs by OpenShift Container Platform SDN. Defaults to 9 which means that a subnet of size /23 is allocated to each host; for example, given the default 10.128.0.0/14 cluster network, this will allocate 10.128.0.0/23, 10.128.2.0/23, 10.128.4.0/23, and so on. This cannot be re-configured after deployment.

openshift_use_flannel

This variable enables flannel as an alternative networking layer instead of the default SDN. If enabling flannel, disable the default SDN with the openshift_use_openshift_sdn variable. For more information, see Using Flannel.

openshift_docker_additional_registries

OpenShift Container Platform adds the specified additional registry or registries to the docker configuration. These are the registries to search.

openshift_docker_insecure_registries

OpenShift Container Platform adds the specified additional insecure registry or registries to the docker configuration. For any of these registries, secure sockets layer (SSL) is not verified. Also, add these registries to openshift_docker_additional_registries.

openshift_docker_blocked_registries

OpenShift Container Platform adds the specified blocked registry or registries to the docker configuration. Block the listed registries. Setting this to all blocks everything not in the other variables.

openshift_metrics_hawkular_hostname

This variable sets the host name for integration with the metrics console by overriding metricsPublicURL in the master configuration for cluster metrics. If you alter this variable, ensure the host name is accessible via your router.

openshift_template_service_broker_namespaces

This variable enables the template service broker by specifying one of more namespaces whose templates will be served by the broker.

2.6.3.2. Configuring Deployment Type

Various defaults used throughout the playbooks and roles used by the installer are based on the deployment type configuration (usually defined in an Ansible inventory file).

Ensure the openshift_deployment_type parameter in your inventory file’s [OSEv3:vars] section is set to openshift-enterprise to install the OpenShift Container Platform variant:

[OSEv3:vars]
openshift_deployment_type=openshift-enterprise

2.6.3.3. Configuring Host Variables

To assign environment variables to hosts during the Ansible installation, indicate the desired variables in the /etc/ansible/hosts file after the host entry in the [masters] or [nodes] sections. For example:

[masters]
ec2-52-6-179-239.compute-1.amazonaws.com openshift_public_hostname=ose3-master.public.example.com

The following table describes variables for use with the Ansible installer that can be assigned to individual host entries:

Table 2.10. Host Variables

VariablePurpose

openshift_hostname

This variable overrides the internal cluster host name for the system. Use this when the system’s default IP address does not resolve to the system host name.

openshift_public_hostname

This variable overrides the system’s public host name. Use this for cloud installations, or for hosts on networks using a network address translation (NAT).

openshift_ip

This variable overrides the cluster internal IP address for the system. Use this when using an interface that is not configured with the default route.

openshift_public_ip

This variable overrides the system’s public IP address. Use this for cloud installations, or for hosts on networks using a network address translation (NAT).

containerized

If set to true, containerized OpenShift Container Platform services are run on the target master and node hosts instead of installed using RPM packages. If set to false or unset, the default RPM method is used. RHEL Atomic Host requires the containerized method, and is automatically selected for you based on the detection of the /run/ostree-booted file. See Installing on Containerized Hosts for more details. Containerized installations are supported starting in OpenShift Container Platform 3.1.1.

openshift_node_labels

This variable adds labels to nodes during installation. See Configuring Node Host Labels for more details.

openshift_node_kubelet_args

This variable is used to configure kubeletArguments on nodes, such as arguments used in container and image garbage collection, and to specify resources per node. kubeletArguments are key value pairs that are passed directly to the Kubelet that match the Kubelet’s command line arguments. kubeletArguments are not migrated or validated and may become invalid if used. These values override other settings in node configuration which may cause invalid configurations. Example usage: {'image-gc-high-threshold': ['90'],'image-gc-low-threshold': ['80']}.

openshift_hosted_router_selector

Default node selector for automatically deploying router pods. See Configuring Node Host Labels for details.

openshift_registry_selector

Default node selector for automatically deploying registry pods. See Configuring Node Host Labels for details.

openshift_docker_options

This variable configures additional docker options within /etc/sysconfig/docker, such as options used in Managing Container Logs. Example usage: "--log-driver json-file --log-opt max-size=1M --log-opt max-file=3". Do not use when running docker as a system container.

openshift_schedulable

This variable configures whether the host is marked as a schedulable node, meaning that it is available for placement of new pods. See Configuring Schedulability on Masters.

openshift_template_service_broker_namespaces

This variable enables the template service broker by specifying one of more namespaces whose templates will be served by the broker. openshift_template_service_broker_namespaces configurable

2.6.3.4. Configuring Master API and Console Ports

To configure the default ports used by the master API and web console, configure the following variables in the /etc/ansible/hosts file:

Table 2.11. Master API and Console Ports

VariablePurpose

openshift_master_api_port

This variable sets the port number to access the OpenShift Container Platform API.

openshift_master_console_port

This variable sets the console port number to access the OpenShift Container Platform console with a web browser.

For example:

openshift_master_api_port=3443
openshift_master_console_port=8756

2.6.3.5. Configuring Cluster Pre-install Checks

Pre-install checks are a set of diagnostic tasks that run as part of the openshift_health_checker Ansible role. They run prior to an Ansible installation of OpenShift Container Platform, ensure that required inventory values are set, and identify potential issues on a host that can prevent or interfere with a successful installation.

The following table describes available pre-install checks that will run before every Ansible installation of OpenShift Container Platform:

Table 2.12. Pre-install Checks

Check NamePurpose

memory_availability

This check ensures that a host has the recommended amount of memory for the specific deployment of OpenShift Container Platform. Default values have been derived from the latest installation documentation. A user-defined value for minimum memory requirements may be set by setting the openshift_check_min_host_memory_gb cluster variable in your inventory file.

disk_availability

This check only runs on etcd, master, and node hosts. It ensures that the mount path for an OpenShift Container Platform installation has sufficient disk space remaining. Recommended disk values are taken from the latest installation documentation. A user-defined value for minimum disk space requirements may be set by setting openshift_check_min_host_disk_gb cluster variable in your inventory file.

docker_storage

Only runs on hosts that depend on the docker daemon (nodes and containerized installations). Checks that docker's total usage does not exceed a user-defined limit. If no user-defined limit is set, docker's maximum usage threshold defaults to 90% of the total size available. The threshold limit for total percent usage can be set with a variable in your inventory file: max_thinpool_data_usage_percent=90. A user-defined limit for maximum thinpool usage may be set by setting the max_thinpool_data_usage_percent cluster variable in your inventory file.

docker_storage_driver

Ensures that the docker daemon is using a storage driver supported by OpenShift Container Platform. If the devicemapper storage driver is being used, the check additionally ensures that a loopback device is not being used.

docker_image_availability

Attempts to ensure that images required by an OpenShift Container Platform installation are available either locally or in at least one of the configured container image registries on the host machine.

package_version

Runs on yum-based systems determining if multiple releases of a required OpenShift Container Platform package are available. Having multiple releases of a package available during an enterprise installation of OpenShift suggests that there are multiple yum repositories enabled for different releases, which may lead to installation problems. This check is skipped if the openshift_release variable is not defined in the inventory file.

package_availability

Runs prior to non-containerized installations of OpenShift Container Platform. Ensures that RPM packages required for the current installation are available.

package_update

Checks whether a yum update or package installation will succeed, without actually performing it or running yum on the host.

To disable specific pre-install checks, include the variable openshift_disable_check with a comma-delimited list of check names in your inventory file. For example:

openshift_disable_check=memory_availability,disk_availability
Note

A similar set of health checks meant to run for diagnostics on existing clusters can be found in Ansible-based Health Checks. Another set of checks for checking certificate expiration can be found in Redeploying Certificates.

2.6.3.6. Configuring System Containers

Important

All system container components are Technology Preview features in OpenShift Container Platform 3.7. They must not be used in production and they are not supported for upgrades to OpenShift Container Platform 3.7. During this phase, they are only meant for use with new cluster installations in non-production environments.

System containers provide a way to containerize services that need to run before the docker daemon is running. They are Docker-formatted containers that use:

System containers are therefore stored and run outside of the traditional docker service. For more details on system container technology, see Running System Containers in the Red Hat Enterprise Linux Atomic Host: Managing Containers documentation.

You can configure your OpenShift Container Platform installation to run certain components as system containers instead of their RPM or standard containerized methods. Currently, the docker and etcd components can be run as system containers in OpenShift Container Platform.

Warning

System containers are currently OS-specific because they require specific versions of atomic and systemd. For example, different system containers are created for RHEL, Fedora, or CentOS. Ensure that the system containers you are using match the OS of the host they will run on. OpenShift Container Platform only supports RHEL and RHEL Atomic as the host OS, so by default system containers built for RHEL are used.

2.6.3.6.1. Running Docker as a System Container
Important

All system container components are Technology Preview features in OpenShift Container Platform 3.7. They must not be used in production and they are not supported for upgrades to OpenShift Container Platform 3.7. During this phase, they are only meant for use with new cluster installations in non-production environments.

The traditional method for using docker in an OpenShift Container Platform cluster is an RPM package installation. For Red Hat Enterprise Linux (RHEL) systems, it must be specifically installed; for RHEL Atomic Host systems, it is provided by default.

However, you can configure your OpenShift Container Platform installation to alternatively run docker on node hosts as a system container. When using the system container method, the container-engine container image and systemd service is used on the host instead of the docker package and service.

To run docker as a system container:

  1. Because the default storage back end for Docker on RHEL 7 is a thin pool on loopback devices, for any RHEL systems you must still configure a thin pool logical volume for docker to use before running the OpenShift Container Platform installation. You can skip these steps for any RHEL Atomic Host systems.

    For any RHEL systems, perform the steps described in the following sections:

    After completing the storage configuration steps, you can leave the RPM installed.

  2. Set the following cluster variable to True in your inventory file in the [OSEv3:vars] section:

    openshift_docker_use_system_container=True

When using the system container method, the following inventory variables for docker are ignored:

  • docker_version
  • docker_upgrade

Further, the following inventory variable must not be used:

  • openshift_docker_options

You can also force docker in the system container to use a specific container registry and repository when pulling the container-engine image instead of from the default registry.access.redhat.com/openshift3/. To do so, set the following cluster variable in your inventory file in the [OSEv3:vars] section:

openshift_docker_systemcontainer_image_override="<registry>/<user>/<image>:<tag>"
2.6.3.6.2. Running etcd as a System Container
Important

All system container components are Technology Preview features in OpenShift Container Platform 3.7. They must not be used in production and they are not supported for upgrades to OpenShift Container Platform 3.7. During this phase, they are only meant for use with new cluster installations in non-production environments.

When using the RPM-based installation method for OpenShift Container Platform, etcd is installed using RPM packages on any RHEL systems. When using the containerized installation method, the rhel7/etcd image is used instead for RHEL or RHEL Atomic Hosts.

However, you can configure your OpenShift Container Platform installation to alternatively run etcd as a system container. Whereas the standard containerized method uses a systemd service named etcd_container, the system container method uses the service name etcd, same as the RPM-based method. The data directory for etcd using this method is /var/lib/etcd.

To run etcd as a system container, set the following cluster variable in your inventory file in the [OSEv3:vars] section:

openshift_use_etcd_system_container=True

2.6.3.7. Configuring a Registry Location

If you are using an image registry other than the default at registry.access.redhat.com, specify the desired registry within the /etc/ansible/hosts file.

oreg_url=example.com/openshift3/ose-${component}:${version}
openshift_examples_modify_imagestreams=true

Table 2.13. Registry Variables

VariablePurpose

oreg_url

Set to the alternate image location. Necessary if you are not using the default registry at registry.access.redhat.com.

openshift_examples_modify_imagestreams

Set to true if pointing to a registry other than the default. Modifies the image stream location to the value of oreg_url.

2.6.3.7.1. Configuring Registry Storage

There are several options for enabling registry storage when using the advanced install:

Option A: NFS Host Group

When the following variables are set, an NFS volume is created during an advanced install with the path <nfs_directory>/<volume_name> on the host within the [nfs] host group. For example, the volume path using these options would be /exports/registry:

[OSEv3:vars]

openshift_hosted_registry_storage_kind=nfs
openshift_hosted_registry_storage_access_modes=['ReadWriteMany']
openshift_hosted_registry_storage_nfs_directory=/exports
openshift_hosted_registry_storage_nfs_options='*(rw,root_squash)'
openshift_hosted_registry_storage_volume_name=registry
openshift_hosted_registry_storage_volume_size=10Gi
Option B: External NFS Host

To use an external NFS volume, one must already exist with a path of <nfs_directory>/<volume_name> on the storage host. The remote volume path using the following options would be nfs.example.com:/exports/registry.

[OSEv3:vars]

openshift_hosted_registry_storage_kind=nfs
openshift_hosted_registry_storage_access_modes=['ReadWriteMany']
openshift_hosted_registry_storage_host=nfs.example.com
openshift_hosted_registry_storage_nfs_directory=/exports
openshift_hosted_registry_storage_volume_name=registry
openshift_hosted_registry_storage_volume_size=10Gi
Option C: OpenStack Platform

An OpenStack storage configuration must already exist.

openshift_hosted_registry_storage_kind=openstack
openshift_hosted_registry_storage_access_modes=['ReadWriteOnce']
openshift_hosted_registry_storage_openstack_filesystem=ext4
openshift_hosted_registry_storage_openstack_volumeID=3a650b4f-c8c5-4e0a-8ca5-eaee11f16c57
openshift_hosted_registry_storage_volume_size=10Gi
Option D: AWS or Another S3 Storage Solution

The simple storage solution (S3) bucket must already exist.

#openshift_hosted_registry_storage_kind=object
#openshift_hosted_registry_storage_provider=s3
#openshift_hosted_registry_storage_s3_accesskey=access_key_id
#openshift_hosted_registry_storage_s3_secretkey=secret_access_key
#openshift_hosted_registry_storage_s3_bucket=bucket_name
#openshift_hosted_registry_storage_s3_region=bucket_region
#openshift_hosted_registry_storage_s3_chunksize=26214400
#openshift_hosted_registry_storage_s3_rootdirectory=/registry
#openshift_hosted_registry_pullthrough=true
#openshift_hosted_registry_acceptschema2=true
#openshift_hosted_registry_enforcequota=true

If you are using a different S3 service, such as Minio or ExoScale, also add the region endpoint parameter:

openshift_hosted_registry_storage_s3_regionendpoint=https://myendpoint.example.com/

2.6.3.8. Configuring GlusterFS Persistent Storage

GlusterFS can be configured to provide peristent storage and dynamic provisioning for OpenShift Container Platform. It can be used both containerized within OpenShift Container Platform and non-containerized on its own nodes.

2.6.3.8.1. Configuring Containerized GlusterFS Persistent Storage

This option utilizes Red Hat Container Native Storage (CNS) for configuring containerized GlusterFS persistent storage in OpenShift Container Platform.

Important

See Containerized GlusterFS Considerations for specific host preparations and prerequisites.

  1. In your inventory file, add glusterfs in the [OSEv3:children] section to enable the [glusterfs] group:

    [OSEv3:children]
    masters
    nodes
    glusterfs
  2. (Optional) Include any of the following role variables in the [OSEv3:vars] section you wish to change:

    [OSEv3:vars]
    openshift_storage_glusterfs_namespace=glusterfs 1
    openshift_storage_glusterfs_name=storage 2
    1
    The project (namespace) to host the storage pods. Defaults to glusterfs.
    2
    A name to identify the GlusterFS cluster, which will be used in resource names. Defaults to storage.
  3. Add a [glusterfs] section with entries for each storage node that will host the GlusterFS storage and include the glusterfs_ip and glusterfs_devices parameters in the form:

    <hostname_or_ip> glusterfs_ip=<ip_address> glusterfs_devices='[ "</path/to/device1/>", "</path/to/device2>", ... ]'

    For example:

    [glusterfs]
    192.168.10.11 glusterfs_ip=192.168.10.11 glusterfs_devices='[ "/dev/xvdc", "/dev/xvdd" ]'
    192.168.10.12 glusterfs_ip=192.168.10.12 glusterfs_devices='[ "/dev/xvdc", "/dev/xvdd" ]'
    192.168.10.13 glusterfs_ip=192.168.10.13 glusterfs_devices='[ "/dev/xvdc", "/dev/xvdd" ]'

    Set glusterfs_devices to a list of raw block devices that will be completely managed as part of a GlusterFS cluster. There must be at least one device listed. Each device must be bare, with no partitions or LVM PVs. Set glusterfs_ip to the IP address that will be used by pods to communicate with the GlusterFS node.

  4. Add the hosts listed under [glusterfs] to the [nodes] group as well:

    [nodes]
    192.168.10.11
    192.168.10.12
    192.168.10.13
  5. After completing the cluster installation per Running the Advanced Installation, run the following from a master to verify the necessary objects were successfully created:

    1. Verfiy that the GlusterFS StorageClass was created:

      # oc get storageclass
      NAME                  TYPE
      glusterfs-storage     kubernetes.io/glusterfs
    2. Verify that the route was created:

      # oc get routes
      NAME            HOST/PORT                                     PATH           SERVICES   PORT   TERMINATION   WILDCARD
      heketi-glusterfs-route  heketi-glusterfs-default.cloudapps.example.com  heketi-glusterfs <all>             None
      Note

      The name for the route will be heketi-glusterfs-route unless the default glusterfs value was overridden using the openshift_glusterfs_storage_name variable in the inventory file.

    3. Use curl to verify the route works correctly:

      # curl http://heketi-glusterfs-default.cloudapps.example.com/hello
      Hello from Heketi.

After successful installation, see Operations on a Red Hat Gluster Storage Pod in an OpenShift Environment to check the status of the GlusterFS clusters.

Dynamic provisioning of GlusterFS volumes can occur by creating a PVC to request storage.

2.6.3.9. Configuring the OpenShift Container Registry

Additional configuration options are available at installation time for the OpenShift Container Registry.

If no registry storage options are used, the default OpenShift Container Platform registry is ephermal and all data will be lost if the pod no longer exists. OpenShift Container Platform also supports a single node NFS-backed registry, but this option lacks redundancy and reliability compared with the GlusterFS-backed option.

2.6.3.9.1. Configuring a Containerized GlusterFS-Backed Registry

Similar to configuring containerized GlusterFS for persistent storage, GlusterFS storage can be configured and deployed for an OpenShift Container Registry during the initial installation of the cluster to offer redundant and more reliable storage for the registry.

Important

See Containerized GlusterFS Considerations for specific host preparations and prerequisites.

Configuration of storage for an OpenShift Container Registry is very similar to configuration for GlusterFS persistent storage in that it can be either containerized or non-containerized. For this containerized method, the following exceptions and additions apply:

  1. In your inventory file, add glusterfs_registry in the [OSEv3:children] section to enable the [glusterfs_registry] group:

    [OSEv3:children]
    masters
    nodes
    glusterfs_registry
  2. Add the following role variable in the [OSEv3:vars] section to enable the GlusterFS-backed registry, provided that the glusterfs_registry group name and the [glusterfs_registry] group exist:

    [OSEv3:vars]
    openshift_hosted_registry_storage_kind=glusterfs
  3. It is recommended to have at least three registry pods, so set the following role variable in the [OSEv3:vars] section:

    openshift_hosted_registry_replicas=3
  4. If you want to specify the volume size for the GlusterFS-backed registry, set the following role variable in [OSEv3:vars] section:

    openshift_hosted_registry_storage_volume_size=10Gi

    If unspecified, the volume size defaults to 5Gi.

  5. The installer will deploy the OpenShift Container Registry pods and associated routers on nodes containing the region=infra label. Add this label on at least one node entry in the [nodes] section, otherwise the registry deployment will fail. For example:

    [nodes]
    192.168.10.14 openshift_schedulable=True openshift_node_labels="{'region': 'infra'}"
  6. Add a [glusterfs_registry] section with entries for each storage node that will host the GlusterFS-backed registry and include the glusterfs_ip and glusterfs_devices parameters in the form:

    <hostname_or_ip> glusterfs_ip=<ip_address> glusterfs_devices='[ "</path/to/device1/>", "</path/to/device2>", ... ]'

    For example:

    [glusterfs_registry]
    192.168.10.14 glusterfs_ip=192.168.10.14 glusterfs_devices='[ "/dev/xvdc", "/dev/xvdd" ]'
    192.168.10.15 glusterfs_ip=192.168.10.15 glusterfs_devices='[ "/dev/xvdc", "/dev/xvdd" ]'
    192.168.10.16 glusterfs_ip=192.168.10.16 glusterfs_devices='[ "/dev/xvdc", "/dev/xvdd" ]'

    Set glusterfs_devices to a list of raw block devices that will be completely managed as part of a GlusterFS cluster. There must be at least one device listed. Each device must be bare, with no partitions or LVM PVs. Set glusterfs_ip to the IP address that will be used by pods to communicate with the GlusterFS node.

  7. Add the hosts listed under [glusterfs_registry] to the [nodes] group as well:

    [nodes]
    192.168.10.14
    192.168.10.15
    192.168.10.16

After successful installation, see Operations on a Red Hat Gluster Storage Pod in an OpenShift Environment to check the status of the GlusterFS clusters.

2.6.3.10. Configuring Global Proxy Options

If your hosts require use of a HTTP or HTTPS proxy in order to connect to external hosts, there are many components that must be configured to use the proxy, including masters, Docker, and builds. Node services only connect to the master API requiring no external access and therefore do not need to be configured to use a proxy.

In order to simplify this configuration, the following Ansible variables can be specified at a cluster or host level to apply these settings uniformly across your environment.

Note

See Configuring Global Build Defaults and Overrides for more information on how the proxy environment is defined for builds.

Table 2.14. Cluster Proxy Variables

VariablePurpose

openshift_http_proxy

This variable specifies the HTTP_PROXY environment variable for masters and the Docker daemon.

openshift_https_proxy

This variable specifices the HTTPS_PROXY environment variable for masters and the Docker daemon.

openshift_no_proxy

This variable is used to set the NO_PROXY environment variable for masters and the Docker daemon. This value should be set to a comma separated list of host names or wildcard host names that should not use the defined proxy. This list will be augmented with the list of all defined OpenShift Container Platform host names by default.

openshift_generate_no_proxy_hosts

This boolean variable specifies whether or not the names of all defined OpenShift hosts and *.cluster.local should be automatically appended to the NO_PROXY list. Defaults to true; set it to false to override this option.

openshift_builddefaults_http_proxy

This variable defines the HTTP_PROXY environment variable inserted into builds using the BuildDefaults admission controller. If openshift_http_proxy is set, this variable will inherit that value; you only need to set this if you want your builds to use a different value.

openshift_builddefaults_https_proxy

This variable defines the HTTPS_PROXY environment variable inserted into builds using the BuildDefaults admission controller. If openshift_https_proxy is set, this variable will inherit that value; you only need to set this if you want your builds to use a different value.

openshift_builddefaults_no_proxy

This variable defines the NO_PROXY environment variable inserted into builds using the BuildDefaults admission controller. If openshift_no_proxy is set, this variable will inherit that value; you only need to set this if you want your builds to use a different value.

openshift_builddefaults_git_http_proxy

This variable defines the HTTP proxy used by git clone operations during a build, defined using the BuildDefaults admission controller. If openshift_builddefaults_http_proxy is set, this variable will inherit that value; you only need to set this if you want your git clone operations to use a different value.

openshift_builddefaults_git_https_proxy

This variable defines the HTTPS proxy used by git clone operations during a build, defined using the BuildDefaults admission controller. If openshift_builddefaults_https_proxy is set, this variable will inherit that value; you only need to set this if you want your git clone operations to use a different value.

2.6.3.11. Configuring the Firewall

Important

If you are changing the default firewall, ensure that each host in your cluster is using the same firewall type to prevent inconsistencies.

Note

While iptables is the default firewall, firewalld is recommended for new installations.

OpenShift Container Platform uses iptables as the default firewall, but you can configure your cluster to use firewalld during the install process.

Because iptables is the default firewall, OpenShift Container Platform is designed to have it configured automatically. However, iptables rules can break OpenShift Container Platform if not configured correctly. The advantages of firewalld include allowing multiple objects to safely share the firewall rules.

To use firewalld as the firewall for an OpenShift Container Platform installation, add the os_firewall_use_firewalld variable to the list of configuration variables in the Ansible host file at install:

[OSEv3:vars]
os_firewall_use_firewalld=True

2.6.3.12. Configuring Schedulability on Masters

Any hosts you designate as masters during the installation process should also be configured as nodes so that the masters are configured as part of the OpenShift SDN. You must do so by adding entries for these hosts to the [nodes] section:

[nodes]
master.example.com

In order to ensure that your masters are not burdened with running pods, they are automatically marked unschedulable by default by the installer, meaning that new pods cannot be placed on the hosts. This is the same as setting the openshift_schedulable=false host variable.

You can manually set a master host to schedulable during installation using the openshift_schedulable=true host variable, though this is not recommended in production environments:

[nodes]
master.example.com openshift_schedulable=true

If you want to change the schedulability of a host post-installation, see Marking Nodes as Unschedulable or Schedulable.

2.6.3.13. Configuring Node Host Labels

You can assign labels to node hosts during the Ansible install by configuring the /etc/ansible/hosts file. Labels are useful for determining the placement of pods onto nodes using the scheduler. Other than region=infra (discussed in Configuring Dedicated Infrastructure Nodes), the actual label names and values are arbitrary and can be assigned however you see fit per your cluster’s requirements.

To assign labels to a node host during an Ansible install, use the openshift_node_labels variable with the desired labels added to the desired node host entry in the [nodes] section. In the following example, labels are set for a region called primary and a zone called east:

[nodes]
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
2.6.3.13.1. Configuring Dedicated Infrastructure Nodes

The openshift_router_selector and openshift_registry_selector Ansible settings determine the label selectors used when placing registry and router pods. They are set to region=infra by default:

# default selectors for router and registry services
# openshift_router_selector='region=infra'
# openshift_registry_selector='region=infra'

The default router and registry will be automatically deployed during installation if nodes exist in the [nodes] section that match the selector settings. For example:

[nodes]
infra-node1.example.com openshift_node_labels="{'region': 'infra','zone': 'default'}"
Important

The registry and router are only able to run on node hosts with the region=infra label. Ensure that at least one node host in your OpenShift Container Platform environment has the region=infra label.

It is recommended for production environments that you maintain dedicated infrastructure nodes where the registry and router pods can run separately from pods used for user applications.

If you do not intend to use OpenShift Container Platform to manage the registry and router, configure the following Ansible settings:

openshift_hosted_manage_registry=false
openshift_hosted_manage_router=false

If you are using an image registry other than the default registry.access.redhat.com, you need to specify the desired registry in the /etc/ansible/hosts file.

As described in Configuring Schedulability on Masters, master hosts are marked unschedulable by default. If you label a master host with region=infra and have no other dedicated infrastructure nodes, you must also explicitly mark these master hosts as schedulable. Otherwise, the registry and router pods cannot be placed anywhere:

[nodes]
master.example.com openshift_node_labels="{'region': 'infra','zone': 'default'}" openshift_schedulable=true

2.6.3.14. Configuring Session Options

Session options in the OAuth configuration are configurable in the inventory file. By default, Ansible populates a sessionSecretsFile with generated authentication and encryption secrets so that sessions generated by one master can be decoded by the others. The default location is /etc/origin/master/session-secrets.yaml, and this file will only be re-created if deleted on all masters.

You can set the session name and maximum number of seconds with openshift_master_session_name and openshift_master_session_max_seconds:

openshift_master_session_name=ssn
openshift_master_session_max_seconds=3600

If provided, openshift_master_session_auth_secrets and openshift_master_encryption_secrets must be equal length.

For openshift_master_session_auth_secrets, used to authenticate sessions using HMAC, it is recommended to use secrets with 32 or 64 bytes:

openshift_master_session_auth_secrets=['DONT+USE+THIS+SECRET+b4NV+pmZNSO']

For openshift_master_encryption_secrets, used to encrypt sessions, secrets must be 16, 24, or 32 characters long, to select AES-128, AES-192, or AES-256:

openshift_master_session_encryption_secrets=['DONT+USE+THIS+SECRET+b4NV+pmZNSO']

2.6.3.15. Configuring Custom Certificates

Custom serving certificates for the public host names of the OpenShift Container Platform API and web console can be deployed during an advanced installation and are configurable in the inventory file.

Note

Custom certificates should only be configured for the host name associated with the publicMasterURL which can be set using openshift_master_cluster_public_hostname. Using a custom serving certificate for the host name associated with the masterURL (openshift_master_cluster_hostname) will result in TLS errors as infrastructure components will attempt to contact the master API using the internal masterURL host.

Certificate and key file paths can be configured using the openshift_master_named_certificates cluster variable:

openshift_master_named_certificates=[{"certfile": "/path/to/custom1.crt", "keyfile": "/path/to/custom1.key", "cafile": "/path/to/custom-ca1.crt"}]

File paths must be local to the system where Ansible will be run. Certificates are copied to master hosts and are deployed within the /etc/origin/master/named_certificates/ directory.

Ansible detects a certificate’s Common Name and Subject Alternative Names. Detected names can be overridden by providing the "names" key when setting openshift_master_named_certificates:

openshift_master_named_certificates=[{"certfile": "/path/to/custom1.crt", "keyfile": "/path/to/custom1.key", "names": ["public-master-host.com"], "cafile": "/path/to/custom-ca1.crt"}]

Certificates configured using openshift_master_named_certificates are cached on masters, meaning that each additional Ansible run with a different set of certificates results in all previously deployed certificates remaining in place on master hosts and within the master configuration file.

If you would like openshift_master_named_certificates to be overwritten with the provided value (or no value), specify the openshift_master_overwrite_named_certificates cluster variable:

openshift_master_overwrite_named_certificates=true

For a more complete example, consider the following cluster variables in an inventory file:

openshift_master_cluster_method=native
openshift_master_cluster_hostname=lb.openshift.com
openshift_master_cluster_public_hostname=custom.openshift.com

To overwrite the certificates on a subsequent Ansible run, you could set the following:

openshift_master_named_certificates=[{"certfile": "/root/STAR.openshift.com.crt", "keyfile": "/root/STAR.openshift.com.key", "names": ["custom.openshift.com"]}]
openshift_master_overwrite_named_certificates=true

2.6.3.16. Configuring Certificate Validity

By default, the certificates used to govern the etcd, master, and kubelet expire after two to five years. The validity (length in days until they expire) for the auto-generated registry, CA, node, and master certificates can be configured during installation using the following variables (default values shown):

[OSEv3:vars]

openshift_hosted_registry_cert_expire_days=730
openshift_ca_cert_expire_days=1825
openshift_node_cert_expire_days=730
openshift_master_cert_expire_days=730
etcd_ca_default_days=1825

These values are also used when redeploying certificates via Ansible post-installation.

2.6.3.17. Configuring Cluster Metrics

Starting with OpenShift Container Platform 3.7, cluster metrics are set to deploy automatically by default during installation:

Note

To disable automatic deployment, set the following cluster variable:

openshift_metrics_install_metrics=false

The OpenShift Container Platform web console uses the data coming from the Hawkular Metrics service to display its graphs. The metrics public URL can be set during cluster installation using the openshift_metrics_hawkular_hostname Ansible variable, which defaults to:

https://hawkular-metrics.{{openshift_master_default_subdomain}}/hawkular/metrics

If you alter this variable, ensure the host name is accessible via your router.

2.6.3.17.1. Configuring Metrics Storage

The openshift_metrics_cassandra_storage_type variable must be set in order to use persistent storage for metrics. If openshift_metrics_cassandra_storage_type is not set, then cluster metrics data is stored in an emptyDir volume, which will be deleted when the Cassandra pod terminates.

There are three options for enabling cluster metrics storage when using the advanced install:

Option A: NFS Host Group

When the following variables are set, an NFS volume is created during an advanced install with path <nfs_directory>/<volume_name> on the host within the [nfs] host group. For example, the volume path using these options would be /exports/metrics:

[OSEv3:vars]

openshift_metrics_storage_kind=nfs
openshift_metrics_storage_access_modes=['ReadWriteOnce']
openshift_metrics_storage_nfs_directory=/exports
openshift_metrics_storage_nfs_options='*(rw,root_squash)'
openshift_metrics_storage_volume_name=metrics
openshift_metrics_storage_volume_size=10Gi
Option B: External NFS Host

To use an external NFS volume, one must already exist with a path of <nfs_directory>/<volume_name> on the storage host.

[OSEv3:vars]

openshift_metrics_storage_kind=nfs
openshift_metrics_storage_access_modes=['ReadWriteOnce']
openshift_metrics_storage_host=nfs.example.com
openshift_metrics_storage_nfs_directory=/exports
openshift_metrics_storage_volume_name=metrics
openshift_metrics_storage_volume_size=10Gi

The remote volume path using the following options would be nfs.example.com:/exports/metrics.

Option C: Dynamic

Use the following variable if your OpenShift Container Platform environment supports dynamic volume provisioning for your cloud provider:

[OSEv3:vars]

openshift_metrics_cassandra_storage_type=dynamic

2.6.3.18. Configuring Cluster Logging

Starting with OpenShift Container Platform 3.7, cluster logging is set to deploy automatically by default during installation.

Note

To disable automatic deployment, set the following cluster variable:

openshift_metrics_install_logging=false
2.6.3.18.1. Configuring Logging Storage

The openshift_logging_storage_kind variable must be set in order to use persistent storage for logging. If openshift_logging_storage_kind is not set, then cluster logging data is stored in an emptyDir volume, which will be deleted when the Elasticsearch pod terminates.

There are three options for enabling cluster logging storage when using the advanced install:

Option A: NFS Host Group

When the following variables are set, an NFS volume is created during an advanced install with path <nfs_directory>/<volume_name> on the host within the [nfs] host group. For example, the volume path using these options would be /exports/logging:

[OSEv3:vars]

openshift_logging_storage_kind=nfs
openshift_logging_storage_access_modes=['ReadWriteOnce']
openshift_logging_storage_nfs_directory=/exports
openshift_logging_storage_nfs_options='*(rw,root_squash)'
openshift_logging_storage_volume_name=logging
openshift_logging_storage_volume_size=10Gi
Option B: External NFS Host

To use an external NFS volume, one must already exist with a path of <nfs_directory>/<volume_name> on the storage host.

[OSEv3:vars]

openshift_logging_storage_kind=nfs
openshift_logging_storage_access_modes=['ReadWriteOnce']
openshift_logging_storage_host=nfs.example.com
openshift_logging_storage_nfs_directory=/exports
openshift_logging_storage_volume_name=logging
openshift_logging_storage_volume_size=10Gi

The remote volume path using the following options would be nfs.example.com:/exports/logging.

Option C: Dynamic

Use the following variable if your OpenShift Container Platform environment supports dynamic volume provisioning for your cloud provider:

[OSEv3:vars]

openshift_logging_storage_kind=dynamic

2.6.3.19. Configuring the Service Catalog

Starting with OpenShift Container Platform 3.7, the service catalog is enabled by default during installation. Enabling the service broker allows service brokers to be registered with the catalog. The web console is also configured to enable an updated landing page for browsing the catalog.

Note

To disable automatic deployment, set the following cluster variables in your inventory file:

openshift_enable_service_catalog=false

When the service catalog is enabled, the web console shows the updated landing page. The OpenShift Ansible broker and template service broker are both enabled as well; see Configuring the OpenShift Ansible Broker and Configuring the Template Service Broker for more information.

2.6.3.20. Configuring the OpenShift Ansible Broker

Starting with OpenShift Container Platform 3.7, the OpenShift Ansible broker (OAB) is enabled by default.

The OAB deploys its own etcd instance separate from the etcd used by the rest of the OpenShift Container Platform cluster. The OAB’s etcd instance requires separate storage using persistent volumes (PVs) to function. If no PV is available, etcd will wait until the PV can be satisfied. The OAB application will enter a CrashLoop state until its etcd instance is available.

Note

The following example shows usage of an NFS host to provide the required PVs, but other persistent storage providers can be used instead.

Some Ansible playbook bundles (APBs) may also require a PV for their own usage. Two APBs are currently provided with OpenShift Container Platform 3.7: MediaWiki and PostgreSQL. Both of these require their own PV to deploy.

To configure the OAB:

  1. In your inventory file, add nfs to the [OSEv3:children] section to enable the [nfs] group:

    [OSEv3:children]
    masters
    nodes
    nfs
  2. Add a [nfs] group section and add the host name for the system that will be the NFS host:

    [nfs]
    master1.example.com
  3. Add the following in the [OSEv3:vars] section:

    openshift_hosted_etcd_storage_kind=nfs
    openshift_hosted_etcd_storage_nfs_options="*(rw,root_squash,sync,no_wdelay)"
    openshift_hosted_etcd_storage_nfs_directory=/opt/osev3-etcd 1
    openshift_hosted_etcd_storage_volume_name=etcd-vol2 2
    openshift_hosted_etcd_storage_access_modes=["ReadWriteOnce"]
    openshift_hosted_etcd_storage_volume_size=1G
    openshift_hosted_etcd_storage_labels={'storage': 'etcd'}
    1 2
    An NFS volume will be created with path <nfs_directory>/<volume_name> on the host within the [nfs] group. For example, the volume path using these options would be /opt/osev3-etcd/etcd-vol2.

    These settings create a persistent volume that is attached to the OAB’s etcd instance during cluster installation.

2.6.3.21. Configuring the Template Service Broker

Starting with OpenShift Container Platform 3.7, the template service broker (TSB) is enabled by default.

To configure the TSB, one or more projects must be defined as the broker’s source namespace(s) for loading templates and image streams into the service catalog. Set the desired projects by modifying the following in your inventory file’s [OSEv3:vars] section:

openshift_template_service_broker_namespaces=['openshift','myproject']

2.6.3.22. Configuring Web Console Customization

The following Ansible variables set master configuration options for customizing the web console. See Customizing the Web Console for more details on these customization options.

Table 2.15. Web Console Customization Variables

VariablePurpose

openshift_master_logout_url

Sets logoutURL in the master configuration. See Changing the Logout URL for details. Example value: http://example.com

openshift_master_extension_scripts

Sets extensionScripts in the master configuration. See Loading Extension Scripts and Stylesheets for details. Example value: ['/path/to/script1.js','/path/to/script2.js']

openshift_master_extension_stylesheets

Sets extensionStylesheets in the master configuration. See Loading Extension Scripts and Stylesheets for details. Example value: ['/path/to/stylesheet1.css','/path/to/stylesheet2.css']

openshift_master_extensions

Sets extensions in the master configuration. See Serving Static Files and Customizing the About Page for details. Example value: [{'name': 'images', 'sourceDirectory': '/path/to/my_images'}]

openshift_master_oauth_template

Sets the OAuth template in the master configuration. See Customizing the Login Page for details. Example value: ['/path/to/login-template.html']

openshift_master_metrics_public_url

Sets metricsPublicURL in the master configuration. See Setting the Metrics Public URL for details. Example value: https://hawkular-metrics.example.com/hawkular/metrics

openshift_master_logging_public_url

Sets loggingPublicURL in the master configuration. See Kibana for details. Example value: https://kibana.example.com

2.6.4. Example Inventory Files

2.6.4.1. Single Master Examples

You can configure an environment with a single master and multiple nodes, and either a single or multiple external etcd hosts.

Note

Moving from a single master cluster to multiple masters after installation is not supported.

Single Master, Single etcd, and Multiple Nodes

The following table describes an example environment for a single master (with a single etcd on the same host), two nodes for hosting user applications, and two nodes with the region=infra label for hosting dedicated infrastructure:

Host NameInfrastructure Component to Install

master.example.com

Master, etcd, and node

node1.example.com

Node

node2.example.com

infra-node1.example.com

Node (with region=infra label)

infra-node2.example.com

You can see these example hosts present in the [masters], [etcd], and [nodes] sections of the following example inventory file:

Single Master, Single etcd, and Multiple Nodes Inventory File

# Create an OSEv3 group that contains the masters, nodes, and etcd groups
[OSEv3:children]
masters
nodes
etcd

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
# SSH user, this user should allow ssh based auth without requiring a password
ansible_ssh_user=root

# If ansible_ssh_user is not root, ansible_become must be set to true
#ansible_become=true

openshift_deployment_type=openshift-enterprise

# uncomment the following to enable htpasswd authentication; defaults to DenyAllPasswordIdentityProvider
#openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider', 'filename': '/etc/origin/master/htpasswd'}]

# host group for masters
[masters]
master.example.com

# host group for etcd
[etcd]
master.example.com

# host group for nodes, includes region info
[nodes]
master.example.com
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
infra-node1.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
infra-node2.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"

To use this example, modify the file to match your environment and specifications, and save it as /etc/ansible/hosts.

Single Master, Multiple etcd, and Multiple Nodes

The following table describes an example environment for a single master, three etcd hosts, two nodes for hosting user applications, and two nodes with the region=infra label for hosting dedicated infrastructure:

Host NameInfrastructure Component to Install

master.example.com

Master and node

etcd1.example.com

etcd

etcd2.example.com

etcd3.example.com

node1.example.com

Node

node2.example.com

infra-node1.example.com

Node (with region=infra label)

infra-node2.example.com

You can see these example hosts present in the [masters], [nodes], and [etcd] sections of the following example inventory file:

Single Master, Multiple etcd, and Multiple Nodes Inventory File

# Create an OSEv3 group that contains the masters, nodes, and etcd groups
[OSEv3:children]
masters
nodes
etcd

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
ansible_ssh_user=root
openshift_deployment_type=openshift-enterprise

# uncomment the following to enable htpasswd authentication; defaults to DenyAllPasswordIdentityProvider
#openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider', 'filename': '/etc/origin/master/htpasswd'}]

# host group for masters
[masters]
master.example.com

# host group for etcd
[etcd]
etcd1.example.com
etcd2.example.com
etcd3.example.com

# host group for nodes, includes region info
[nodes]
master.example.com
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
infra-node1.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
infra-node2.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"

To use this example, modify the file to match your environment and specifications, and save it as /etc/ansible/hosts.

2.6.4.2. Multiple Masters Examples

You can configure an environment with multiple masters, multiple etcd hosts, and multiple nodes. Configuring multiple masters for high availability (HA) ensures that the cluster has no single point of failure.

Note

Moving from a single master cluster to multiple masters after installation is not supported.

When configuring multiple masters, the advanced installation supports the native high availability (HA) method. This method leverages the native HA master capabilities built into OpenShift Container Platform and can be combined with any load balancing solution.

If a host is defined in the [lb] section of the inventory file, Ansible installs and configures HAProxy automatically as the load balancing solution. If no host is defined, it is assumed you have pre-configured an external load balancing solution of your choice to balance the master API (port 8443) on all master hosts.

Note

This HAProxy load balancer is intended to demonstrate the API server’s HA mode and is not recommended for production environments. If you are deploying to a cloud provider, Red Hat recommends deploying a cloud-native TCP-based load balancer or take other steps to provide a highly available load balancer.

For an external load balancing solution, you must have:

  • A pre-created load balancer VIP configured for SSL passthrough.
  • A VIP listening on the port specified by the openshift_master_api_port and openshift_master_console_port values (8443 by default) and proxying back to all master hosts on that port.
  • A domain name for VIP registered in DNS.

    • The domain name will become the value of both openshift_master_cluster_public_hostname and openshift_master_cluster_hostname in the OpenShift Container Platform installer.

See External Load Balancer Integrations for more information. For more on the high availability master architecture, see Kubernetes Infrastructure.

Note

The advanced installation method does not currently support multiple HAProxy load balancers in an active-passive setup. See the Load Balancer Administration documentation for post-installation amendments.

To configure multiple masters, refer to the following section.

Multiple Masters with Multiple etcd

The following describes an example environment for three masters using the native HA method:, one HAProxy load balancer, three etcd hosts, two nodes for hosting user applications, and two nodes with the region=infra label for hosting dedicated infrastructure:

Host NameInfrastructure Component to Install

master1.example.com

Master (clustered using native HA) and node

master2.example.com

master3.example.com

lb.example.com

HAProxy to load balance API master endpoints

etcd1.example.com

etcd

etcd2.example.com

etcd3.example.com

node1.example.com

Node

node2.example.com

infra-node1.example.com

Node (with region=infra label)

infra-node2.example.com

You can see these example hosts present in the [masters], [etcd], [lb], and [nodes] sections of the following example inventory file:

Multiple Masters Using HAProxy Inventory File

# Create an OSEv3 group that contains the master, nodes, etcd, and lb groups.
# The lb group lets Ansible configure HAProxy as the load balancing solution.
# Comment lb out if your load balancer is pre-configured.
[OSEv3:children]
masters
nodes
etcd
lb

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
ansible_ssh_user=root
openshift_deployment_type=openshift-enterprise

# Uncomment the following to enable htpasswd authentication; defaults to
# DenyAllPasswordIdentityProvider.
#openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider', 'filename': '/etc/origin/master/htpasswd'}]

# Native high availbility cluster method with optional load balancer.
# If no lb group is defined installer assumes that a load balancer has
# been preconfigured. For installation the value of
# openshift_master_cluster_hostname must resolve to the load balancer
# or to one or all of the masters defined in the inventory if no load
# balancer is present.
openshift_master_cluster_method=native
openshift_master_cluster_hostname=openshift-cluster.example.com
openshift_master_cluster_public_hostname=openshift-cluster.example.com

# apply updated node defaults
openshift_node_kubelet_args={'pods-per-core': ['10'], 'max-pods': ['250'], 'image-gc-high-threshold': ['90'], 'image-gc-low-threshold': ['80']}

# enable ntp on masters to ensure proper failover
openshift_clock_enabled=true

# host group for masters
[masters]
master1.example.com
master2.example.com
master3.example.com

# host group for etcd
[etcd]
etcd1.example.com
etcd2.example.com
etcd3.example.com

# Specify load balancer host
[lb]
lb.example.com

# host group for nodes, includes region info
[nodes]
master[1:3].example.com
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
infra-node1.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
infra-node2.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"

To use this example, modify the file to match your environment and specifications, and save it as /etc/ansible/hosts.

Multiple Masters with Master and etcd on the Same Host

The following describes an example environment for three masters using the native HA method (with etcd on each host), one HAProxy load balancer, two nodes for hosting user applications, and two nodes with the region=infra label for hosting dedicated infrastructure:

Host NameInfrastructure Component to Install

master1.example.com

Master (clustered using native HA) and node with etcd on each host

master2.example.com

master3.example.com

lb.example.com

HAProxy to load balance API master endpoints

node1.example.com

Node

node2.example.com

infra-node1.example.com

Node (with region=infra label)

infra-node2.example.com

You can see these example hosts present in the [masters], [etcd], [lb], and [nodes] sections of the following example inventory file:

# Create an OSEv3 group that contains the master, nodes, etcd, and lb groups.
# The lb group lets Ansible configure HAProxy as the load balancing solution.
# Comment lb out if your load balancer is pre-configured.
[OSEv3:children]
masters
nodes
etcd
lb

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
ansible_ssh_user=root
openshift_deployment_type=openshift-enterprise

# Uncomment the following to enable htpasswd authentication; defaults to
# DenyAllPasswordIdentityProvider.
#openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider', 'filename': '/etc/origin/master/htpasswd'}]

# Native high availability cluster method with optional load balancer.
# If no lb group is defined installer assumes that a load balancer has
# been preconfigured. For installation the value of
# openshift_master_cluster_hostname must resolve to the load balancer
# or to one or all of the masters defined in the inventory if no load
# balancer is present.
openshift_master_cluster_method=native
openshift_master_cluster_hostname=openshift-cluster.example.com
openshift_master_cluster_public_hostname=openshift-cluster.example.com

# host group for masters
[masters]
master1.example.com
master2.example.com
master3.example.com

# host group for etcd
[etcd]
master1.example.com
master2.example.com
master3.example.com

# Specify load balancer host
[lb]
lb.example.com

# host group for nodes, includes region info
[nodes]
master[1:3].example.com
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
infra-node1.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
infra-node2.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"

To use this example, modify the file to match your environment and specifications, and save it as /etc/ansible/hosts.

2.6.5. Running the Advanced Installation

After you have configured Ansible by defining an inventory file in /etc/ansible/hosts, you run the advanced installation playbook via Ansible. OpenShift Container Platform installations are currently supported using the RPM-based installer, while the containerized installer is currently a Technology Preview feature.

The installer uses modularized playbooks allowing administrators to install specific components as needed. By breaking up the roles and playbooks, there is better targeting of ad hoc administration tasks. This results in an increased level of control during installations and results in time savings.

Note

The playbooks and their ordering are detailed below in Running Individual Component Playbooks.

2.6.5.1. Running the RPM-based Installer

The RPM-based installer uses Ansible installed via RPM packages to run playbooks and configuration files available on the local host. To run the installer, use the following command, specifying -i if your inventory file located somewhere other than /etc/ansible/hosts:

If you are using a proxy, you must add the IP address of the etcd endpoints to the openshift_no_proxy cluster variable in your inventory file.

Note

If you are not using a proxy, you can skip this step.

In OpenShift Container Platform:

# ansible-playbook  [-i /path/to/inventory] \
    /usr/share/ansible/openshift-ansible/playbooks/byo/config.yml

If for any reason the installation fails, before re-running the installer, see Known Issues to check for any specific instructions or workarounds.

2.6.5.2. Running the Containerized Installer

Important

All system container components are Technology Preview features in OpenShift Container Platform 3.7. They must not be used in production and they are not supported for upgrades to OpenShift Container Platform 3.7. During this phase, they are only meant for use with new cluster installations in non-production environments.

The openshift3/ose-ansible image is a containerized version of the OpenShift Container Platform installer that runs as a system container. System containers are stored and run outside of the traditional docker service. Functionally, using the containerized installer is the same as using the traditional RPM-based installer, except it is running in a containerized environment instead of directly on the host.

  1. Use the Docker CLI to pull the image locally:

    $ docker pull registry.access.redhat.com/openshift3/ose-ansible:v3.7
  2. The installer system container must be stored in OSTree instead of defaulting to docker daemon storage. Use the Atomic CLI to import the installer image from the local docker engine to OSTree storage:

    $ atomic pull --storage ostree \
        docker:registry.access.redhat.com/openshift3/ose-ansible:v3.7
  3. Install the system container so it is set up as a systemd service:

    $ atomic install --system \
        --storage=ostree \
        --name=openshift-installer \1
        --set INVENTORY_FILE=/path/to/inventory \2
        docker:registry.access.redhat.com/openshift3/ose-ansible:v3.7
    1
    Sets the name for the systemd service.
    2
    Specify the location for your inventory file on your local workstation.
  4. Use the systemctl command to start the installer service as you would any other systemd service. This command initiates the cluster installation:

    $ systemctl start openshift-installer

    If for any reason the installation fails, before re-running the installer, see Known Issues to check for any specific instructions or workarounds.

  5. After the installation completes, you can uninstall the system container if you want. However, if you need to run the installer again to run any other playbooks later, you would have to follow this procedure again.

    To uninstall the system container:

    $ atomic uninstall openshift-installer
2.6.5.2.1. Running Other Playbooks

After you have completed the cluster installation, if you want to later run any other playbooks using the containerized installer (for example, cluster upgrade playbooks), you can use the PLAYBOOK_FILE environment variable. The default value is playbooks/byo/config.yml, which is the main cluster installation playbook, but you can set it to the path of another playbook inside the container.

For example:

$ atomic install --system \
    --storage=ostree \
    --name=openshift-installer \
    --set INVENTORY_FILE=/etc/ansible/hosts \
    --set PLAYBOOK_FILE=playbooks/byo/openshift-cluster/upgrades/v3_7/upgrade.yml \1
    docker:registry.access.redhat.com/openshift3/ose-ansible:v3.7
1
Set PLAYBOOK_FILE to the relative path of the playbook starting at the playbooks/ directory. Playbooks mentioned elsewhere in OpenShift Container Platform documentation assume use of the RPM-based installer, so use this relative path instead when using the containerized installer.

2.6.5.3. Running Individual Component Playbooks

The main installation playbook /usr/share/ansible/openshift-ansible/playbooks/byo/config.yml runs a set of individual component playbooks in a specific order, and the installer reports back at the end what phases you have gone through. If the installation fails during a phase, you are notified on the screen along with the errors from the Ansible run.

After you resolve the issue, rather than run the entire installation over again, you can pick up from the failed phase. You must then run each of the remaining playbooks in order:

# ansible-playbook  [-i /path/to/inventory] <playbook_file_location>

The following table is sorted in order of when each individual component playbook is run:

Table 2.16. Individual Component Playbook Run Order

Playbook NameFile Location

Health Check

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-checks/pre-install.yml

etcd Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-etcd/config.yml

NFS Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-nfs/config.yml

Load Balancer Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-loadbalancer/config.yml

Master Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-master/config.yml

Master Additional Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-master/additional_config.yml

Node Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-node/config.yml

GlusterFS Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-glusterfs/config.yml

Hosted Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-hosted.yml

Metrics Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-metrics.yml

Logging Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-logging.yml

Prometheus Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-prometheus.yml

Service Catalog Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/service-catalog.yml

Management Install

/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-management/config.yml

2.6.6. Verifying the Installation

After the installation completes:

  1. Verify that the master is started and nodes are registered and reporting in Ready status. On the master host, run the following as root:

    # oc get nodes
    
    NAME                        STATUS                     AGE
    master.example.com          Ready,SchedulingDisabled   165d
    node1.example.com           Ready                      165d
    node2.example.com           Ready                      165d
  2. To verify that the web console is installed correctly, use the master host name and the web console port number to access the web console with a web browser.

    For example, for a master host with a host name of master.openshift.com and using the default port of 8443, the web console would be found at https://master.openshift.com:8443/console.

Note

The default port for the console is 8443. If this was changed during the installation, the port can be found at openshift_master_console_port in the /etc/ansible/hosts file.

Verifying Multiple etcd Hosts

If you installed multiple etcd hosts:

  1. First, verify that the etcd package, which provides the etcdctl command, is installed:

    # yum install etcd
  2. On a master host, verify the etcd cluster health, substituting for the FQDNs of your etcd hosts in the following:

    # etcdctl -C \
        https://etcd1.example.com:2379,https://etcd2.example.com:2379,https://etcd3.example.com:2379 \
        --ca-file=/etc/origin/master/master.etcd-ca.crt \
        --cert-file=/etc/origin/master/master.etcd-client.crt \
        --key-file=/etc/origin/master/master.etcd-client.key cluster-health
  3. Also verify the member list is correct:

    # etcdctl -C \
        https://etcd1.example.com:2379,https://etcd2.example.com:2379,https://etcd3.example.com:2379 \
        --ca-file=/etc/origin/master/master.etcd-ca.crt \
        --cert-file=/etc/origin/master/master.etcd-client.crt \
        --key-file=/etc/origin/master/master.etcd-client.key member list
Verifying Multiple Masters Using HAProxy

If you installed multiple masters using HAProxy as a load balancer, browse to the following URL according to your [lb] section definition and check HAProxy’s status:

http://<lb_hostname>:9000

You can verify your installation by consulting the HAProxy Configuration documentation.

2.6.7. Uninstalling OpenShift Container Platform

You can uninstall OpenShift Container Platform hosts in your cluster by running the uninstall.yml playbook. This playbook deletes OpenShift Container Platform content installed by Ansible, including:

  • Configuration
  • Containers
  • Default templates and image streams
  • Images
  • RPM packages

The playbook will delete content for any hosts defined in the inventory file that you specify when running the playbook. If you want to uninstall OpenShift Container Platform across all hosts in your cluster, run the playbook using the inventory file you used when installing OpenShift Container Platform initially or ran most recently:

# ansible-playbook [-i /path/to/file] \
    /usr/share/ansible/openshift-ansible/playbooks/adhoc/uninstall.yml

2.6.7.1. Uninstalling Nodes

You can also uninstall node components from specific hosts using the uninstall.yml playbook while leaving the remaining hosts and cluster alone:

Warning

This method should only be used when attempting to uninstall specific node hosts and not for specific masters or etcd hosts, which would require further configuration changes within the cluster.

  1. First follow the steps in Deleting Nodes to remove the node object from the cluster, then continue with the remaining steps in this procedure.
  2. Create a different inventory file that only references those hosts. For example, to only delete content from one node:

    [OSEv3:children]
    nodes 1
    
    [OSEv3:vars]
    ansible_ssh_user=root
    openshift_deployment_type=openshift-enterprise
    
    [nodes]
    node3.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}" 2
    1
    Only include the sections that pertain to the hosts you are interested in uninstalling.
    2
    Only include hosts that you want to uninstall.
  3. Specify that new inventory file using the -i option when running the uninstall.yml playbook:

    # ansible-playbook -i /path/to/new/file \
        /usr/share/ansible/openshift-ansible/playbooks/adhoc/uninstall.yml

When the playbook completes, all OpenShift Container Platform content should be removed from any specified hosts.

2.6.8. Known Issues

  • On failover in multiple master clusters, it is possible for the controller manager to overcorrect, which causes the system to run more pods than what was intended. However, this is a transient event and the system does correct itself over time. See https://github.com/kubernetes/kubernetes/issues/10030 for details.
  • On failure of the Ansible installer, you must start from a clean operating system installation. If you are using virtual machines, start from a fresh image. If you are using bare metal machines, see Uninstalling OpenShift Container Platform for instructions.

2.6.9. What’s Next?

Now that you have a working OpenShift Container Platform instance, you can:

2.7. Disconnected Installation

2.7.1. Overview

Frequently, portions of a datacenter may not have access to the Internet, even via proxy servers. Installing OpenShift Container Platform in these environments is considered a disconnected installation.

An OpenShift Container Platform disconnected installation differs from a regular installation in two primary ways:

  • The OpenShift Container Platform software channels and repositories are not available via Red Hat’s content distribution network.
  • OpenShift Container Platform uses several containerized components. Normally, these images are pulled directly from Red Hat’s Docker registry. In a disconnected environment, this is not possible.

A disconnected installation ensures the OpenShift Container Platform software is made available to the relevant servers, then follows the same installation process as a standard connected installation. This topic additionally details how to manually download the container images and transport them onto the relevant servers.

Once installed, in order to use OpenShift Container Platform, you will need source code in a source control repository (for example, Git). This topic assumes that an internal Git repository is available that can host source code and this repository is accessible from the OpenShift Container Platform nodes. Installing the source control repository is outside the scope of this document.

Also, when building applications in OpenShift Container Platform, your build may have some external dependencies, such as a Maven Repository or Gem files for Ruby applications. For this reason, and because they might require certain tags, many of the Quickstart templates offered by OpenShift Container Platform may not work on a disconnected environment. However, while Red Hat container images try to reach out to external repositories by default, you can configure OpenShift Container Platform to use your own internal repositories. For the purposes of this document, we assume that such internal repositories already exist and are accessible from the OpenShift Container Platform nodes hosts. Installing such repositories is outside the scope of this document.

Note

You can also have a Red Hat Satellite server that provides access to Red Hat content via an intranet or LAN. For environments with Satellite, you can synchronize the OpenShift Container Platform software onto the Satellite for use with the OpenShift Container Platform servers.

Red Hat Satellite 6.1 also introduces the ability to act as a Docker registry, and it can be used to host the OpenShift Container Platform containerized components. Doing so is outside of the scope of this document.

2.7.2. Prerequisites

This document assumes that you understand OpenShift Container Platform’s overall architecture and that you have already planned out what the topology of your environment will look like.

2.7.3. Required Software and Components

In order to pull down the required software repositories and container images, you will need a Red Hat Enterprise Linux (RHEL) 7 server with access to the Internet and at least 100GB of additional free space. All steps in this section should be performed on the Internet-connected server as the root system user.

2.7.3.1. Syncing Repositories

Before you sync with the required repositories, you may need to import the appropriate GPG key:

# rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

If the key is not imported, the indicated package is deleted after syncing the repository.

To sync the required repositories:

  1. Register the server with the Red Hat Customer Portal. You must use the login and password associated with the account that has access to the OpenShift Container Platform subscriptions:

    # subscription-manager register
  2. Pull the latest subscription data from RHSM:

    # subscription-manager refresh
  3. Attach to a subscription that provides OpenShift Container Platform channels. You can find the list of available subscriptions using:

    # subscription-manager list --available --matches '*OpenShift*'

    Then, find the pool ID for the subscription that provides OpenShift Container Platform, and attach it:

    # subscription-manager attach --pool=<pool_id>
    # subscription-manager repos --disable="*"
    # subscription-manager repos \
        --enable="rhel-7-server-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-fast-datapath-rpms" \
        --enable="rhel-7-server-ose-3.7-rpms"
  4. The yum-utils command provides the reposync utility, which lets you mirror yum repositories, and createrepo can create a usable yum repository from a directory:

    # yum -y install yum-utils createrepo docker git

    You will need up to 110GB of free space in order to sync the software. Depending on how restrictive your organization’s policies are, you could re-connect this server to the disconnected LAN and use it as the repository server. You could use USB-connected storage and transport the software to another server that will act as the repository server. This topic covers these options.

  5. Make a path to where you want to sync the software (either locally or on your USB or other device):

    # mkdir -p </path/to/repos>
  6. Sync the packages and create the repository for each of them. You will need to modify the command for the appropriate path you created above:

    # for repo in \
    rhel-7-server-rpms \
    rhel-7-server-extras-rpms \
    rhel-7-fast-datapath-rpms \
    rhel-7-server-ose-3.7-rpms
    do
      reposync --gpgcheck -lm --repoid=${repo} --download_path=/path/to/repos
      createrepo -v </path/to/repos/>${repo} -o </path/to/repos/>${repo}
    done

2.7.3.2. Syncing Images

To sync the container images:

  1. Start the Docker daemon:

    # systemctl start docker
  2. Pull all of the required OpenShift Container Platform containerized components. Replace <tag> with v3.7.9 for the latest version.

    # docker pull registry.access.redhat.com/openshift3/ose-ansible:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-cluster-capacity:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-deployer:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-docker-builder:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-docker-registry:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-egress-http-proxy:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-egress-router:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-f5-router:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-federation:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-haproxy-router:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-keepalived-ipfailover:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-pod:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-sti-builder:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose:<tag>
    # docker pull registry.access.redhat.com/openshift3/container-engine:<tag>
    # docker pull registry.access.redhat.com/openshift3/efs-provisioner:<tag>
    # docker pull registry.access.redhat.com/openshift3/node:<tag>
    # docker pull registry.access.redhat.com/openshift3/openvswitch:<tag>
    Note

    If you are using NFS, you need the ose-recycler image. Otherwise, the volumes will not recycle, potentially causing errors.

  3. Pull all of the required OpenShift Container Platform containerized components for the additional centralized log aggregation and metrics aggregation components. Replace <tag> with v3.7.9 for the latest version.

    # docker pull registry.access.redhat.com/openshift3/logging-auth-proxy:<tag>
    # docker pull registry.access.redhat.com/openshift3/logging-curator:<tag>
    # docker pull registry.access.redhat.com/openshift3/logging-deployer:<tag>
    # docker pull registry.access.redhat.com/openshift3/logging-elasticsearch:<tag>
    # docker pull registry.access.redhat.com/openshift3/logging-fluentd:<tag>
    # docker pull registry.access.redhat.com/openshift3/logging-kibana:<tag>
    # docker pull registry.access.redhat.com/openshift3/metrics-cassandra:<tag>
    # docker pull registry.access.redhat.com/openshift3/metrics-deployer:<tag>
    # docker pull registry.access.redhat.com/openshift3/metrics-hawkular-metrics:<tag>
    # docker pull registry.access.redhat.com/openshift3/metrics-hawkular-openshift-agent:<tag>
    # docker pull registry.access.redhat.com/openshift3/metrics-heapster:<tag>
  4. For the service catalog, OpenShift Asnible broker, and template service broker features (as described in Advanced Installation), pull the following images. Replace <tag> with v3.7.9 for the latest version.

    # docker pull registry.access.redhat.com/openshift3/ose-service-catalog:<tag>
    # docker pull registry.access.redhat.com/openshift3/ose-ansible-service-broker:<tag>
    # docker pull registry.access.redhat.com/openshift3/mediawiki-apb:<tag>
    # docker pull registry.access.redhat.com/openshift3/postgresql-apb:<tag>
  5. Pull the Red Hat-certified Source-to-Image (S2I) builder images that you intend to use in your OpenShift environment. You can pull the following images:

    • jboss-eap70-openshift
    • jboss-amq-62
    • jboss-datagrid65-openshift
    • jboss-decisionserver62-openshift
    • jboss-eap64-openshift
    • jboss-eap70-openshift
    • jboss-webserver30-tomcat7-openshift
    • jboss-webserver30-tomcat8-openshift
    • jenkins-1-rhel7
    • jenkins-2-rhel7
    • jenkins-slave-base-rhel7
    • jenkins-slave-maven-rhel7
    • jenkins-slave-nodejs-rhel7
    • mongodb
    • mysql
    • nodejs
    • perl
    • php
    • postgresql
    • python
    • redhat-sso70-openshift
    • ruby

      Make sure to indicate the correct tag specifying the desired version number. For example, to pull both the previous and latest version of the Tomcat image:

      # docker pull \
      registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:latest
      # docker pull \
      registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:1.1
  6. If you are using a stand-alone registry or plan to enable the registry console with the integrated registry, you must pull the registry-console image.

    Replace <tag> with v3.7.9 for the latest version.

    # docker pull registry.access.redhat.com/openshift3/registry-console:<tag>

2.7.3.3. Preparing Images for Export

Container images can be exported from a system by first saving them to a tarball and then transporting them:

  1. Make and change into a repository home directory:

    # mkdir </path/to/repos/images>
    # cd </path/to/repos/images>
  2. Export the OpenShift Container Platform containerized components:

    # docker save -o ose3-images.tar \
        registry.access.redhat.com/openshift3/ose-ansible \
        registry.access.redhat.com/openshift3/ose-cluster-capacity \
        registry.access.redhat.com/openshift3/ose-deployer \
        registry.access.redhat.com/openshift3/ose-docker-builder \
        registry.access.redhat.com/openshift3/ose-docker-registry \
        registry.access.redhat.com/openshift3/ose-egress-http-proxy \
        registry.access.redhat.com/openshift3/ose-egress-router \
        registry.access.redhat.com/openshift3/ose-f5-router \
        registry.access.redhat.com/openshift3/ose-federation \
        registry.access.redhat.com/openshift3/ose-haproxy-router \
        registry.access.redhat.com/openshift3/ose-keepalived-ipfailover \
        registry.access.redhat.com/openshift3/ose-pod \
        registry.access.redhat.com/openshift3/ose-sti-builder \
        registry.access.redhat.com/openshift3/ose \
        registry.access.redhat.com/openshift3/container-engine \
        registry.access.redhat.com/openshift3/efs-provisioner \
        registry.access.redhat.com/openshift3/node \
        registry.access.redhat.com/openshift3/openvswitch
  3. If you synchronized the metrics and log aggregation images, export:

    # docker save -o ose3-logging-metrics-images.tar \
        registry.access.redhat.com/openshift3/logging-auth-proxy \
        registry.access.redhat.com/openshift3/logging-curator \
        registry.access.redhat.com/openshift3/logging-deployer \
        registry.access.redhat.com/openshift3/logging-elasticsearch \
        registry.access.redhat.com/openshift3/logging-fluentd \
        registry.access.redhat.com/openshift3/logging-kibana \
        registry.access.redhat.com/openshift3/metrics-cassandra \
        registry.access.redhat.com/openshift3/metrics-deployer \
        registry.access.redhat.com/openshift3/metrics-hawkular-metrics \
        registry.access.redhat.com/openshift3/metrics-hawkular-openshift-agent \
        registry.access.redhat.com/openshift3/metrics-heapster
  4. Export the S2I builder images that you synced in the previous section. For example, if you synced only the Jenkins and Tomcat images:

    # docker save -o ose3-builder-images.tar \
        registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:latest \
        registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:1.1 \
        registry.access.redhat.com/openshift3/jenkins-1-rhel7 \
        registry.access.redhat.com/openshift3/jenkins-2-rhel7 \
        registry.access.redhat.com/openshift3/jenkins-slave-base-rhel7 \
        registry.access.redhat.com/openshift3/jenkins-slave-maven-rhel7 \
        registry.access.redhat.com/openshift3/jenkins-slave-nodejs-rhel7

2.7.4. Repository Server

During the installation (and for later updates, should you so choose), you will need a webserver to host the repositories. RHEL 7 can provide the Apache webserver.

Option 1: Re-configuring as a Web server

If you can re-connect the server where you synchronized the software and images to your LAN, then you can simply install Apache on the server:

# yum install httpd

Skip to Placing the Software.

Option 2: Building a Repository Server

If you need to build a separate server to act as the repository server, install a new RHEL 7 system with at least 110GB of space. On this repository server during the installation, make sure you select the Basic Web Server option.

2.7.4.1. Placing the Software

  1. If necessary, attach the external storage, and then copy the repository files into Apache’s root folder. Note that the below copy step (cp -a) should be substituted with move (mv) if you are repurposing the server you used to sync:

    # cp -a /path/to/repos /var/www/html/
    # chmod -R +r /var/www/html/repos
    # restorecon -vR /var/www/html
  2. Add the firewall rules:

    # firewall-cmd --permanent --add-service=http
    # firewall-cmd --reload
  3. Enable and start Apache for the changes to take effect:

    # systemctl enable httpd
    # systemctl start httpd

2.7.5. OpenShift Container Platform Systems

2.7.5.1. Building Your Hosts

At this point you can perform the initial creation of the hosts that will be part of the OpenShift Container Platform environment. It is recommended to use the latest version of RHEL 7 and to perform a minimal installation. You will also want to pay attention to the other OpenShift Container Platform-specific prerequisites.

Once the hosts are initially built, the repositories can be set up.

2.7.5.2. Connecting the Repositories

On all of the relevant systems that will need OpenShift Container Platform software components, create the required repository definitions. Place the following text in the /etc/yum.repos.d/ose.repo file, replacing <server_IP> with the IP or host name of the Apache server hosting the software repositories:

[rhel-7-server-rpms]
name=rhel-7-server-rpms
baseurl=http://<server_IP>/repos/rhel-7-server-rpms
enabled=1
gpgcheck=0
[rhel-7-server-extras-rpms]
name=rhel-7-server-extras-rpms
baseurl=http://<server_IP>/repos/rhel-7-server-extras-rpms
enabled=1
gpgcheck=0
[rhel-7-fast-datapath-rpms]
name=rhel-7-fast-datapath-rpms
baseurl=http://<server_IP>/repos/rhel-7-fast-datapath-rpms
enabled=1
gpgcheck=0
[rhel-7-server-ose-3.7-rpms]
name=rhel-7-server-ose-3.7-rpms
baseurl=http://<server_IP>/repos/rhel-7-server-ose-3.7-rpms
enabled=1
gpgcheck=0

2.7.5.3. Host Preparation

At this point, the systems are ready to continue to be prepared following the OpenShift Container Platform documentation.

Skip the section titled Host Registration and start with Installing Base Packages.

2.7.6. Installing OpenShift Container Platform

2.7.6.1. Importing OpenShift Container Platform Containerized Components

To import the relevant components, securely copy the images from the connected host to the individual OpenShift Container Platform hosts:

# scp /var/www/html/repos/images/ose3-images.tar root@<openshift_host_name>:
# ssh root@<openshift_host_name> "docker load -i ose3-images.tar"

If you prefer, you could use wget on each OpenShift Container Platform host to fetch the tar file, and then perform the Docker import command locally. Perform the same steps for the metrics and logging images, if you synchronized them.

On the host that will act as an OpenShift Container Platform master, copy and import the builder images:

# scp /var/www/html/images/ose3-builder-images.tar root@<openshift_master_host_name>:
# ssh root@<openshift_master_host_name> "docker load -i ose3-builder-images.tar"

2.7.6.2. Running the OpenShift Container Platform Installer

You can now choose to follow the quick or advanced OpenShift Container Platform installation instructions in the documentation.

2.7.6.3. Creating the Internal Docker Registry

You now need to create the internal Docker registry.

If you want to install a stand-alone registry, you must pull the registry-console container image and set deployment_subtype=registry in the inventory file.

2.7.7. Post-Installation Changes

In one of the previous steps, the S2I images were imported into the Docker daemon running on one of the OpenShift Container Platform master hosts. In a connected installation, these images would be pulled from Red Hat’s registry on demand. Since the Internet is not available to do this, the images must be made available in another Docker registry.

OpenShift Container Platform provides an internal registry for storing the images that are built as a result of the S2I process, but it can also be used to hold the S2I builder images. The following steps assume you did not customize the service IP subnet (172.30.0.0/16) or the Docker registry port (5000).

2.7.7.1. Re-tagging S2I Builder Images

  1. On the master host where you imported the S2I builder images, obtain the service address of your Docker registry that you installed on the master:

    # export REGISTRY=$(oc get service docker-registry -t '{{.spec.clusterIP}}{{"\n"}}')
  2. Next, tag all of the builder images that you synced and exported before pushing them into the OpenShift Container Platform Docker registry. For example, if you synced and exported only the Tomcat image:

    # docker tag \
    registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:1.1 \
    $REGISTRY:5000/openshift/webserver30-tomcat7-openshift:1.1
    # docker tag \
    registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:latest \
    $REGISTRY:5000/openshift/webserver30-tomcat7-openshift:1.2
    # docker tag \
    registry.access.redhat.com/jboss-webserver-3/webserver30-tomcat7-openshift:latest \
    $REGISTRY:5000/openshift/webserver30-tomcat7-openshift:latest

2.7.7.2. Configuring a Registry Location

If you are using an image registry other than the default at registry.access.redhat.com, specify the desired registry within the /etc/ansible/hosts file.

oreg_url=example.com/openshift3/ose-${component}:${version}
openshift_examples_modify_imagestreams=true

Depending on your registry, you may need to configure:

openshift_docker_additional_registries=example.com
oopenshift_docker_insecure_registries=example.com

Table 2.17. Registry Variables

VariablePurpose

oreg_url

Set to the alternate image location. Necessary if you are not using the default registry at registry.access.redhat.com.

openshift_examples_modify_imagestreams

Set to true if pointing to a registry other than the default. Modifies the image stream location to the value of oreg_url.

openshift_docker_additional_registries

Set openshift_docker_additional_registries to add its value in the add_registry line in /etc/sysconfig/docker. With add_registry, you can add your own registry to be used for Docker search and Docker pull. Use the add_registry option to list a set of registries, each prepended with --add-registry flag. The first registry added will be the first registry searched. For example, add_registry=--add-registry registry.access.redhat.com --add-registry example.com.

openshift_docker_insecure_registries

Set openshift_docker_insecure_registries to add its value in the insecure_registry line in /etc/sysconfig/docker. If you have a registry secured with HTTPS but do not have proper certificates distributed, you can tell Docker not to look for full authorization by adding the registry to the insecure_registry line and uncommenting it. For example, insecure_registry—​insecure-registry example.com.

2.7.7.3. Creating an Administrative User

Pushing the container images into OpenShift Container Platform’s Docker registry requires a user with cluster-admin privileges. Because the default OpenShift Container Platform system administrator does not have a standard authorization token, they cannot be used to log in to the Docker registry.

To create an administrative user:

  1. Create a new user account in the authentication system you are using with OpenShift Container Platform. For example, if you are using local htpasswd-based authentication:

    # htpasswd -b /etc/openshift/openshift-passwd <admin_username> <password>
  2. The external authentication system now has a user account, but a user must log in to OpenShift Container Platform before an account is created in the internal database. Log in to OpenShift Container Platform for this account to be created. This assumes you are using the self-signed certificates generated by OpenShift Container Platform during the installation:

    # oc login --certificate-authority=/etc/origin/master/ca.crt \
        -u <admin_username> https://<openshift_master_host>:8443
  3. Get the user’s authentication token:

    # MYTOKEN=$(oc whoami -t)
    # echo $MYTOKEN
    iwo7hc4XilD2KOLL4V1O55ExH2VlPmLD-W2-JOd6Fko

2.7.7.4. Modifying the Security Policies

  1. Using oc login switches to the new user. Switch back to the OpenShift Container Platform system administrator in order to make policy changes:

    # oc login -u system:admin
  2. In order to push images into the OpenShift Container Platform Docker registry, an account must have the image-builder security role. Add this to your OpenShift Container Platform administrative user:

    # oadm policy add-role-to-user system:image-builder <admin_username>
  3. Next, add the administrative role to the user in the openshift project. This allows the administrative user to edit the openshift project, and, in this case, push the container images:

    # oadm policy add-role-to-user admin <admin_username> -n openshift

2.7.7.5. Editing the Image Stream Definitions

The openshift project is where all of the image streams for builder images are created by the installer. They are loaded by the installer from the /usr/share/openshift/examples directory. Change all of the definitions by deleting the image streams which had been loaded into OpenShift Container Platform’s database, then re-create them:

  1. Delete the existing image streams:

    # oc delete is -n openshift --all
  2. Make a backup of the files in /usr/share/openshift/examples/ if you desire. Next, edit the file image-streams-rhel7.json in the /usr/share/openshift/examples/image-streams folder. You will find an image stream section for each of the builder images. Edit the spec stanza to point to your internal Docker registry.

    For example, change:

    "spec": {
      "dockerImageRepository": "registry.access.redhat.com/rhscl/mongodb-26-rhel7",

    to:

    "spec": {
      "dockerImageRepository": "172.30.69.44:5000/openshift/mongodb-26-rhel7",

    In the above, the repository name was changed from rhscl to openshift. You will need to ensure the change, regardless of whether the repository is rhscl, openshift3, or another directory. Every definition should have the following format:

    <registry_ip>:5000/openshift/<image_name>

    Repeat this change for every image stream in the file. Ensure you use the correct IP address that you determined earlier. When you are finished, save and exit. Repeat the same process for the JBoss image streams in the /usr/share/openshift/examples/xpaas-streams/jboss-image-streams.json file.

  3. Load the updated image stream definitions:

    # oc create -f /usr/share/openshift/examples/image-streams/image-streams-rhel7.json -n openshift
    # oc create -f /usr/share/openshift/examples/xpaas-streams/jboss-image-streams.json -n openshift

2.7.7.6. Loading the Container Images

At this point the system is ready to load the container images.

  1. Log in to the Docker registry using the token and registry service IP obtained earlier:

    # docker login -u adminuser -e mailto:adminuser@abc.com \
       -p $MYTOKEN $REGISTRY:5000
  2. Push the Docker images:

    # docker push $REGISTRY:5000/openshift/webserver30-tomcat7-openshift:1.1
    # docker push $REGISTRY:5000/openshift/webserver30-tomcat7-openshift:1.2
    # docker push $REGISTRY:5000/openshift/webserver30-tomcat7-openshift:latest
  3. Verify that all the image streams now have the tags populated:

    # oc get imagestreams -n openshift
    NAME                                 DOCKER REPO                                                      TAGS                                     UPDATED
    jboss-webserver30-tomcat7-openshift  $REGISTRY/jboss-webserver-3/webserver30-jboss-tomcat7-openshift  1.1,1.1-2,1.1-6 + 2 more...              2 weeks ago
    ...

2.7.8. Installing a Router

At this point, the OpenShift Container Platform environment is almost ready for use. It is likely that you will want to install and configure a router.

2.8. Installing a Stand-alone Deployment of OpenShift Container Registry

2.8.1. About OpenShift Container Registry

OpenShift Container Platform is a fully-featured platform-as-a-service (PaaS) enterprise solution that includes an integrated container registry called OpenShift Container Registry (OCR). Alternatively, instead of deploying OpenShift Container Platform as a full PaaS environment for developers, you can install OCR as a stand-alone container registry to run on-premise or in the cloud.

When installing a stand-alone deployment of OCR, a cluster of masters and nodes is still installed, similar to a typical OpenShift Container Platform installation. Then, the container registry is deployed to run on the cluster. This stand-alone deployment option is useful for administrators that want a container registry, but do not require the full OpenShift Container Platform environment that includes the developer-focused web console and application build and deployment tools.

Note

OCR should not be confused with the upstream project Atomic Registry, which is a different implementation using a non-Kubernetes deployment method that leverages systemd and local configuration files to manage services.

OCR provides the following capabilities:

Administrators may want to deploy a stand-alone OCR to manage a registry separately that supports multiple OpenShift Container Platform clusters. A stand-alone OCR also enables administrators to separate their registry to satisfy their own security or compliance requirements.

2.8.2. Minimum Hardware Requirements

Installing a stand-alone OCR has the following hardware requirements:

  • Physical or virtual system, or an instance running on a public or private IaaS.
  • Base OS: RHEL 7.3 or 7.4 with the "Minimal" installation option and the latest packages from the RHEL 7 Extras channel, or RHEL Atomic Host 7.4.2 or later.
  • NetworkManager 1.0 or later
  • 2 vCPU.
  • Minimum 16 GB RAM.
  • Minimum 15 GB hard disk space for the file system containing /var/.
  • An additional minimum 15 GB unallocated space to be used for Docker’s storage back end; see Configuring Docker Storage for details.
Important

OpenShift Container Platform only supports servers with x86_64 architecture.

Note

Meeting the /var/ file system sizing requirements in RHEL Atomic Host requires making changes to the default configuration. See Managing Storage in Red Hat Enterprise Linux Atomic Host for instructions on configuring this during or after installation.

2.8.3. Supported System Topologies

The following system topologies are supported for stand-alone OCR:

All-in-one

A single host that includes the master, node, etcd, and registry components.

Multiple Masters (Highly-Available)

Three hosts with all components included on each (master, node, etcd, and registry), with the masters configured for native high-availability.

2.8.4. Host Preparation

Before installing stand-alone OCR, all of the same steps detailed in the Host Preparation topic for installing a full OpenShift Container Platform PaaS must be performed. This includes registering and subscribing the host(s) to the proper repositories, installing or updating certain packages, and setting up Docker and its storage requirements.

Follow the steps in the Host Preparation topic, then continue to Installation Methods.

2.8.5. Installation Methods

To install a stand-alone registry, use either of the standard installation methods (quick or advanced) used to install any variant of OpenShift Container Platform.

2.8.5.1. Quick Installation for Stand-alone OpenShift Container Registry

When using the quick installation method to install stand-alone OCR, start the interactive installation by running:

$ atomic-openshift-installer install

Then follow the on-screen instructions to install a new registry. The installation questions will be largely the same as if you were installing a full OpenShift Container Platform PaaS, but when you reach the following screen:

Which variant would you like to install?


(1) OpenShift Container Platform
(2) Registry

Be sure to choose 2 to follow the registry installation path.

Note

For further usage details on the quick installer in general, see the full topic at Quick Installation.

2.8.5.2. Advanced Installation for Stand-alone OpenShift Container Registry

When using the advanced installation method to install stand-alone OCR, use the same steps for installing a full OpenShift Container Platform PaaS using Ansible described in the full Advanced Installation topic. The main difference is that you must set deployment_subtype=registry in the inventory file within the [OSEv3:vars] section for the playbooks to follow the registry installation path.

See the following example inventory files for the different supported system topologies:

All-in-one Stand-alone OpenShift Container Registry Inventory File

# Create an OSEv3 group that contains the masters and nodes groups
[OSEv3:children]
masters
nodes

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
# SSH user, this user should allow ssh based auth without requiring a password
ansible_ssh_user=root

openshift_master_default_subdomain=apps.test.example.com

# If ansible_ssh_user is not root, ansible_become must be set to true
#ansible_become=true

openshift_deployment_type=openshift-enterprise
deployment_subtype=registry 1

# uncomment the following to enable htpasswd authentication; defaults to DenyAllPasswordIdentityProvider
#openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider', 'filename': '/etc/origin/master/htpasswd'}]

# host group for masters
[masters]
registry.example.com

# host group for nodes, includes region info
[nodes]
registry.example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}" openshift_schedulable=true 2

1
Set deployment_subtype=registry to ensure installation of stand-alone OCR and not a full OpenShift Container Platform environment.
2
Set openshift_schedulable=true on the node entry to make the single node schedulable for pod placement.

Multiple Masters (Highly-Available) Stand-alone OpenShift Container Registry Inventory File

# Create an OSEv3 group that contains the master, nodes, etcd, and lb groups.
# The lb group lets Ansible configure HAProxy as the load balancing solution.
# Comment lb out if your load balancer is pre-configured.
[OSEv3:children]
masters
nodes
etcd
lb

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
ansible_ssh_user=root
openshift_deployment_type=openshift-enterprise
deployment_subtype=registry 1

openshift_master_default_subdomain=apps.test.example.com

# Uncomment the following to enable htpasswd authentication; defaults to
# DenyAllPasswordIdentityProvider.
#openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider', 'filename': '/etc/origin/master/htpasswd'}]

# Native high availability cluster method with optional load balancer.
# If no lb group is defined installer assumes that a load balancer has
# been preconfigured. For installation the value of
# openshift_master_cluster_hostname must resolve to the load balancer
# or to one or all of the masters defined in the inventory if no load
# balancer is present.
openshift_master_cluster_method=native
openshift_master_cluster_hostname=openshift-cluster.example.com
openshift_master_cluster_public_hostname=openshift-cluster.example.com

# apply updated node defaults
openshift_node_kubelet_args={'pods-per-core': ['10'], 'max-pods': ['250'], 'image-gc-high-threshold': ['90'], 'image-gc-low-threshold': ['80']}

# override the default controller lease ttl
#osm_controller_lease_ttl=30

# enable ntp on masters to ensure proper failover
openshift_clock_enabled=true

# host group for masters
[masters]
master1.example.com
master2.example.com
master3.example.com

# host group for etcd
[etcd]
etcd1.example.com
etcd2.example.com
etcd3.example.com

# Specify load balancer host
[lb]
lb.example.com

# host group for nodes, includes region info
[nodes]
master[1:3].example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}" openshift_schedulable=true
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"

1
Set deployment_subtype=registry to ensure installation of stand-alone OCR and not a full OpenShift Container Platform environment.

After you have configured Ansible by defining an inventory file in /etc/ansible/hosts, you can run the advanced installation using the following playbook:

# ansible-playbook /usr/share/ansible/openshift-ansible/playbooks/byo/config.yml
Note

For more detailed usage information on the advanced installation method, including a comprehensive list of available Ansible variables, see the full topic at Advanced Installation.

Chapter 3. Setting up the Registry

3.1. Registry Overview

3.1.1. About the Registry

OpenShift Container Platform can build container images from your source code, deploy them, and manage their lifecycle. To enable this, OpenShift Container Platform provides an internal, integrated Docker registry that can be deployed in your OpenShift Container Platform environment to locally manage images.

3.1.2. Integrated or Stand-alone Registries

During an initial installation of a full OpenShift Container Platform cluster, it is likely that the registry was deployed automatically during the installation process. If it was not, or if you want to further customize the configuration of your registry, see Deploying a Registry on Existing Clusters.

While it can be deployed to run as an integrated part of your full OpenShift Container Platform cluster, the OpenShift Container Platform registry can alternatively be installed separately as a stand-alone container image registry.

To install a stand-alone registry, follow Installing a Stand-alone Registry. This installation path deploys an all-in-one cluster running a registry and specialized web console.

3.2. Deploying a Registry on Existing Clusters

3.2.1. Overview

If the integrated registry was not previously deployed automatically during the initial installation of your OpenShift Container Platform cluster, or if it is no longer running successfully and you need to redeploy it on your existing cluster, see the following sections for options on deploying a new registry.

Note

This topic is not required if you installed a stand-alone registry.

3.2.2. Deploying the Registry

To deploy the integrated Docker registry, use the oadm registry command as a user with cluster administrator privileges. For example:

$ oadm registry --config=/etc/origin/master/admin.kubeconfig \1
    --service-account=registry \2
    --images='registry.access.redhat.com/openshift3/ose-${component}:${version}' 3
1
--config is the path to the CLI configuration file for the cluster administrator.
2
--service-account is the service account used to run the registry’s pod.
3
Required to pull the correct image for OpenShift Container Platform.

This creates a service and a deployment configuration, both called docker-registry. Once deployed successfully, a pod is created with a name similar to docker-registry-1-cpty9.

To see a full list of options that you can specify when creating the registry:

$ oadm registry --help

3.2.3. Deploying the Registry as a DaemonSet

Use the oadm registry command to deploy the registry as a DaemonSet with the --daemonset option.

Daemonsets ensure that when nodes are created, they contain copies of a specified pod. When the nodes are removed, the pods are garbage collected.

For more information on DaemonSets, see Using Daemonsets.

3.2.4. Registry Compute Resources

By default, the registry is created with no settings for compute resource requests or limits. For production, it is highly recommended that the deployment configuration for the registry be updated to set resource requests and limits for the registry pod. Otherwise, the registry pod will be considered a BestEffort pod.

See Compute Resources for more information on configuring requests and limits.

3.2.5. Storage for the Registry

The registry stores container images and metadata. If you simply deploy a pod with the registry, it uses an ephemeral volume that is destroyed if the pod exits. Any images anyone has built or pushed into the registry would disappear.

This section lists the supported registry storage drivers.

The following list includes storage drivers that need to be configured in the registry’s configuration file:

General registry storage configuration options are supported.

The following storage options need to be configured through the filesystem driver:

Note

For more information on supported persistent storage drivers, see Configuring Persistent Storage and Persistent Storage Examples.

3.2.5.1. Production Use

For production use, attach a remote volume or define and use the persistent storage method of your choice.

For example, to use an existing persistent volume claim:

$ oc volume deploymentconfigs/docker-registry --add --name=registry-storage -t pvc \
     --claim-name=<pvc_name> --overwrite
Note

See Known Issues if using a scaled registry with a shared NFS volume.

3.2.5.1.1. Use Amazon S3 as a Storage Back-end

There is also an option to use Amazon Simple Storage Service storage with the internal Docker registry. It is a secure cloud storage manageable through AWS Management Console. To use it, the registry’s configuration file must be manually edited and mounted to the registry pod. However, before you start with the configuration, look at upstream’s recommended steps.

Take a default YAML configuration file as a base and replace the filesystem entry in the storage section with s3 entry such as below. The resulting storage section may look like this:

storage:
  cache:
    layerinfo: inmemory
  delete:
    enabled: true
  s3:
    accesskey: awsaccesskey 1
    secretkey: awssecretkey 2
    region: us-west-1
    regionendpoint: http://myobjects.local
    bucket: bucketname
    encrypt: true
    keyid: mykeyid
    secure: true
    v4auth: false
    chunksize: 5242880
    rootdirectory: /s3/object/name/prefix
1
Replace with your Amazon access key.
2
Replace with your Amazon secret key.

All of the s3 configuration options are documented in upstream’s driver reference documentation.

Overriding the registry configuration will take you through the additional steps on mounting the configuration file into pod.

Warning

When the registry runs on the S3 storage back-end, there are reported issues.

3.2.5.2. Non-Production Use

For non-production use, you can use the --mount-host=<path> option to specify a directory for the registry to use for persistent storage. The registry volume is then created as a host-mount at the specified <path>.

Important

The --mount-host option mounts a directory from the node on which the registry container lives. If you scale up the docker-registry deployment configuration, it is possible that your registry pods and containers will run on different nodes, which can result in two or more registry containers, each with its own local storage. This will lead to unpredictable behavior, as subsequent requests to pull the same image repeatedly may not always succeed, depending on which container the request ultimately goes to.

The --mount-host option requires that the registry container run in privileged mode. This is automatically enabled when you specify --mount-host. However, not all pods are allowed to run privileged containers by default. If you still want to use this option, create the registry and specify that it use the registry service account that was created during installation:

$ oadm registry --service-account=registry \
    --config=/etc/origin/master/admin.kubeconfig \
    --images='registry.access.redhat.com/openshift3/ose-${component}:${version}' \
    --mount-host=<path>
Important

The Docker registry pod runs as user 1001. This user must be able to write to the host directory. You may need to change directory ownership to user ID 1001 with this command:

$ sudo chown 1001:root <path>

3.2.6. Enabling the Registry Console

OpenShift Container Platform provides a web-based interface to the integrated registry. This registry console is an optional component for browsing and managing images. It is deployed as a stateless service running as a pod.

Note

If you installed OpenShift Container Platform as a stand-alone registry, the registry console is already deployed and secured automatically during installation.

Important

If Cockpit is already running, you’ll need to shut it down before proceeding in order to avoid a port conflict (9090 by default) with the registry console.

3.2.6.1. Deploying the Registry Console

Important

You must first have exposed the registry.

  1. Create a passthrough route in the default project. You will need this when creating the registry console application in the next step.

    $ oc create route passthrough --service registry-console \
        --port registry-console \
        -n default
  2. Deploy the registry console application. Replace <openshift_oauth_url> with the URL of the OpenShift Container Platform OAuth provider, which is typically the master.

    $ oc new-app -n default --template=registry-console \
        -p OPENSHIFT_OAUTH_PROVIDER_URL="https://<openshift_oauth_url>:8443" \
        -p REGISTRY_HOST=$(oc get route docker-registry -n default --template='{{ .spec.host }}') \
        -p COCKPIT_KUBE_URL=$(oc get route registry-console -n default --template='https://{{ .spec.host }}')
Note

If the redirection URL is wrong when you are trying to log in to the registry console, check your OAuth client with oc get oauthclients.

  1. Finally, use a web browser to view the console using the route URI.

3.2.6.2. Securing the Registry Console

By default, the registry console generates self-signed TLS certificates if deployed manually per the steps in Deploying the Registry Console. See Troubleshooting the Registry Console for more information.

Use the following steps to add your organization’s signed certificates as a secret volume. This assumes your certificates are available on the the oc client host.

  1. Create a .cert file containing the certificate and key. Format the file with:

    • One or more BEGIN CERTIFICATE blocks for the server certificate and the intermediate certificate authorities
    • A block containing a BEGIN PRIVATE KEY or similar for the key. The key must not be encrypted

      For example:

      -----BEGIN CERTIFICATE-----
      MIIDUzCCAjugAwIBAgIJAPXW+CuNYS6QMA0GCSqGSIb3DQEBCwUAMD8xKTAnBgNV
      BAoMIGI0OGE2NGNkNmMwNTQ1YThhZTgxOTEzZDE5YmJjMmRjMRIwEAYDVQQDDAls
      ...
      -----END CERTIFICATE-----
      -----BEGIN CERTIFICATE-----
      MIIDUzCCAjugAwIBAgIJAPXW+CuNYS6QMA0GCSqGSIb3DQEBCwUAMD8xKTAnBgNV
      BAoMIGI0OGE2NGNkNmMwNTQ1YThhZTgxOTEzZDE5YmJjMmRjMRIwEAYDVQQDDAls
      ...
      -----END CERTIFICATE-----
      -----BEGIN PRIVATE KEY-----
      MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCyOJ5garOYw0sm
      8TBCDSqQ/H1awGMzDYdB11xuHHsxYS2VepPMzMzryHR137I4dGFLhvdTvJUH8lUS
      ...
      -----END PRIVATE KEY-----

      The registry console loads a certificate from the /etc/cockpit/ws-certs.d directory. It uses the last file with a .cert extension in alphabetical order. Therefore, the .cert file should contain at least two PEM blocks formatted in the OpenSSL style.

      If no certificate is found, a self-signed certificate is created using the openssl command and stored in the 0-self-signed.cert file.

  2. Create the secret:

    $ oc secrets new console-secret \
        /path/to/console.cert
  3. Add the secrets to the registry-console deployment configuration:

    $ oc volume dc/registry-console --add --type=secret \
        --secret-name=console-secret -m /etc/cockpit/ws-certs.d

    This triggers a new deployment of the registry console to include your signed certificates.

3.2.6.3. Troubleshooting the Registry Console

3.2.6.3.1. Debug Mode

The registry console debug mode is enabled using an environment variable. The following command redeploys the registry console in debug mode:

$ oc set env dc registry-console G_MESSAGES_DEBUG=cockpit-ws,cockpit-wrapper

Enabling debug mode allows more verbose logging to appear in the registry console’s pod logs.

3.2.6.3.2. Display SSL Certificate Path

To check which certificate the registry console is using, a command can be run from inside the console pod.

  1. List the pods in the default project and find the registry console’s pod name:

    $ oc get pods -n default
    NAME                       READY     STATUS    RESTARTS   AGE
    registry-console-1-rssrw   1/1       Running   0          1d
  2. Using the pod name from the previous command, get the certificate path that the cockpit-ws process is using. This example shows the console using the auto-generated certificate:

    $ oc exec registry-console-1-rssrw remotectl certificate
    certificate: /etc/cockpit/ws-certs.d/0-self-signed.cert

3.3. Accessing the Registry

3.3.1. Viewing Logs

To view the logs for the Docker registry, use the oc logs command with the deployment configuration:

$ oc logs dc/docker-registry
2015-05-01T19:48:36.300593110Z time="2015-05-01T19:48:36Z" level=info msg="version=v2.0.0+unknown"
2015-05-01T19:48:36.303294724Z time="2015-05-01T19:48:36Z" level=info msg="redis not configured" instance.id=9ed6c43d-23ee-453f-9a4b-031fea646002
2015-05-01T19:48:36.303422845Z time="2015-05-01T19:48:36Z" level=info msg="using inmemory layerinfo cache" instance.id=9ed6c43d-23ee-453f-9a4b-031fea646002
2015-05-01T19:48:36.303433991Z time="2015-05-01T19:48:36Z" level=info msg="Using OpenShift Auth handler"
2015-05-01T19:48:36.303439084Z time="2015-05-01T19:48:36Z" level=info msg="listening on :5000" instance.id=9ed6c43d-23ee-453f-9a4b-031fea646002

3.3.2. File Storage

Tag and image metadata is stored in OpenShift Container Platform, but the registry stores layer and signature data in a volume that is mounted into the registry container at /registry. As oc exec does not work on privileged containers, to view a registry’s contents you must manually SSH into the node housing the registry pod’s container, then run docker exec on the container itself:

  1. List the current pods to find the pod name of your Docker registry:

    # oc get pods

    Then, use oc describe to find the host name for the node running the container:

    # oc describe pod <pod_name>
  2. Log into the desired node:

    # ssh node.example.com
  3. List the running containers from the default project on the node host and identify the container ID for the Docker registry:

    # docker ps --filter=name=registry_docker-registry.*_default_
  4. List the registry contents using the oc rsh command:

    # oc rsh dc/docker-registry find /registry
    /registry/docker
    /registry/docker/registry
    /registry/docker/registry/v2
    /registry/docker/registry/v2/blobs 1
    /registry/docker/registry/v2/blobs/sha256
    /registry/docker/registry/v2/blobs/sha256/ed
    /registry/docker/registry/v2/blobs/sha256/ed/ede17b139a271d6b1331ca3d83c648c24f92cece5f89d95ac6c34ce751111810
    /registry/docker/registry/v2/blobs/sha256/ed/ede17b139a271d6b1331ca3d83c648c24f92cece5f89d95ac6c34ce751111810/data 2
    /registry/docker/registry/v2/blobs/sha256/a3
    /registry/docker/registry/v2/blobs/sha256/a3/a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4
    /registry/docker/registry/v2/blobs/sha256/a3/a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4/data
    /registry/docker/registry/v2/blobs/sha256/f7
    /registry/docker/registry/v2/blobs/sha256/f7/f72a00a23f01987b42cb26f259582bb33502bdb0fcf5011e03c60577c4284845
    /registry/docker/registry/v2/blobs/sha256/f7/f72a00a23f01987b42cb26f259582bb33502bdb0fcf5011e03c60577c4284845/data
    /registry/docker/registry/v2/repositories 3
    /registry/docker/registry/v2/repositories/p1
    /registry/docker/registry/v2/repositories/p1/pause 4
    /registry/docker/registry/v2/repositories/p1/pause/_manifests
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions/sha256
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions/sha256/e9a2ac6418981897b399d3709f1b4a6d2723cd38a4909215ce2752a5c068b1cf
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions/sha256/e9a2ac6418981897b399d3709f1b4a6d2723cd38a4909215ce2752a5c068b1cf/signatures 5
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions/sha256/e9a2ac6418981897b399d3709f1b4a6d2723cd38a4909215ce2752a5c068b1cf/signatures/sha256
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions/sha256/e9a2ac6418981897b399d3709f1b4a6d2723cd38a4909215ce2752a5c068b1cf/signatures/sha256/ede17b139a271d6b1331ca3d83c648c24f92cece5f89d95ac6c34ce751111810
    /registry/docker/registry/v2/repositories/p1/pause/_manifests/revisions/sha256/e9a2ac6418981897b399d3709f1b4a6d2723cd38a4909215ce2752a5c068b1cf/signatures/sha256/ede17b139a271d6b1331ca3d83c648c24f92cece5f89d95ac6c34ce751111810/link 6
    /registry/docker/registry/v2/repositories/p1/pause/_uploads 7
    /registry/docker/registry/v2/repositories/p1/pause/_layers 8
    /registry/docker/registry/v2/repositories/p1/pause/_layers/sha256
    /registry/docker/registry/v2/repositories/p1/pause/_layers/sha256/a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4
    /registry/docker/registry/v2/repositories/p1/pause/_layers/sha256/a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4/link 9
    /registry/docker/registry/v2/repositories/p1/pause/_layers/sha256/f72a00a23f01987b42cb26f259582bb33502bdb0fcf5011e03c60577c4284845
    /registry/docker/registry/v2/repositories/p1/pause/_layers/sha256/f72a00a23f01987b42cb26f259582bb33502bdb0fcf5011e03c60577c4284845/link
    1
    This directory stores all layers and signatures as blobs.
    2
    This file contains the blob’s contents.
    3
    This directory stores all the image repositories.
    4
    This directory is for a single image repository p1/pause.
    5
    This directory contains signatures for a particular image manifest revision.
    6
    This file contains a reference back to a blob (which contains the signature data).
    7
    This directory contains any layers that are currently being uploaded and staged for the given repository.
    8
    This directory contains links to all the layers this repository references.
    9
    This file contains a reference to a specific layer that has been linked into this repository via an image.

3.3.3. Accessing the Registry Directly

For advanced usage, you can access the registry directly to invoke docker commands. This allows you to push images to or pull them from the integrated registry directly using operations like docker push or docker pull. To do so, you must be logged in to the registry using the docker login command. The operations you can perform depend on your user permissions, as described in the following sections.

3.3.3.1. User Prerequisites

To access the registry directly, the user that you use must satisfy the following, depending on your intended usage:

  • For any direct access, you must have a regular user, if one does not already exist, for your preferred identity provider. A regular user can generate an access token required for logging in to the registry. System users, such as system:admin, cannot obtain access tokens and, therefore, cannot access the registry directly.

    For example, if you are using HTPASSWD authentication, you can create one using the following command:

    # htpasswd /etc/origin/openshift-htpasswd <user_name>
  • The user must have the system:registry role. To add this role:

    # oadm policy add-role-to-user system:registry <user_name>
  • Have the admin role for the project associated with the Docker operation. For example, if accessing images in the global openshift project:

     $ oadm policy add-role-to-user admin <user_name> -n openshift
  • For writing or pushing images, for example when using the docker push command, the user must have the system:image-builder role. To add this role:

    $ oadm policy add-role-to-user system:image-builder <user_name>

For more information on user permissions, see Managing Role Bindings.

3.3.3.2. Logging in to the Registry

Note

Ensure your user satisfies the prerequisites for accessing the registry directly.

To log in to the registry directly:

  1. Ensure you are logged in to OpenShift Container Platform as a regular user:

    $ oc login
  2. Log in to the Docker registry by using your access token:

    docker login -u $(oc whoami) -p $(oc whoami -t) <registry_ip>:<port>

3.3.3.3. Pushing and Pulling Images

After logging in to the registry, you can perform docker pull and docker push operations against your registry.

Important

You can pull arbitrary images, but if you have the system:registry role added, you can only push images to the registry in your project.

In the following examples, we use:

Component

Value

<registry_ip>

172.30.124.220

<port>

5000

<project>

openshift

<image>

busybox

<tag>

omitted (defaults to latest)

  1. Pull an arbitrary image:

    $ docker pull docker.io/busybox
  2. Tag the new image with the form <registry_ip>:<port>/<project>/<image>. The project name must appear in this pull specification for OpenShift Container Platform to correctly place and later access the image in the registry.

    $ docker tag docker.io/busybox 172.30.124.220:5000/openshift/busybox
    Note

    Your regular user must have the system:image-builder role for the specified project, which allows the user to write or push an image. Otherwise, the docker push in the next step will fail. To test, you can create a new project to push the busybox image.

  3. Push the newly-tagged image to your registry:

    $ docker push 172.30.124.220:5000/openshift/busybox
    ...
    cf2616975b4a: Image successfully pushed
    Digest: sha256:3662dd821983bc4326bee12caec61367e7fb6f6a3ee547cbaff98f77403cab55

3.3.4. Accessing Registry Metrics

The OpenShift Container Registry provides an endpoint for Prometheus metrics. Prometheus is a stand-alone, open source systems monitoring and alerting toolkit.

The metrics are exposed at the /extensions/v2/metrics path of the registry endpoint. However, this route must first be enabled; see Extended Registry Configuration for instructions.

The following is a simple example of a metrics query:

$ curl -s -u <user>:<secret> \ 1
    http://172.30.30.30:5000/extensions/v2/metrics | grep openshift | head -n 10

# HELP openshift_build_info A metric with a constant '1' value labeled by major, minor, git commit & git version from which OpenShift was built.
# TYPE openshift_build_info gauge
openshift_build_info{gitCommit="67275e1",gitVersion="v3.6.0-alpha.1+67275e1-803",major="3",minor="6+"} 1
# HELP openshift_registry_request_duration_seconds Request latency summary in microseconds for each operation
# TYPE openshift_registry_request_duration_seconds summary
openshift_registry_request_duration_seconds{name="test/origin-pod",operation="blobstore.create",quantile="0.5"} 0
openshift_registry_request_duration_seconds{name="test/origin-pod",operation="blobstore.create",quantile="0.9"} 0
openshift_registry_request_duration_seconds{name="test/origin-pod",operation="blobstore.create",quantile="0.99"} 0
openshift_registry_request_duration_seconds_sum{name="test/origin-pod",operation="blobstore.create"} 0
openshift_registry_request_duration_seconds_count{name="test/origin-pod",operation="blobstore.create"} 5
1
<user> can be arbitrary, but <secret> must match the value specified in the registry configuration.

See the upstream Prometheus documentation for more advanced queries and recommended visualizers.

3.4. Securing and Exposing the Registry

3.4.1. Overview

By default, the OpenShift Container Registry is secured during cluster installation so that it serves traffic via TLS. A passthrough route is also created by default to expose the service externally.

If for any reason your registry has not been secured or exposed, see the following sections for steps on how to manually do so.

3.4.2. Manually Securing the Registry

To manually secure the registry to serve traffic via TLS:

  1. Deploy the registry.
  2. Fetch the service IP and port of the registry:

    $ oc get svc/docker-registry
    NAME              LABELS                                    SELECTOR                  IP(S)            PORT(S)
    docker-registry   docker-registry=default                   docker-registry=default   172.30.124.220   5000/TCP
  3. You can use an existing server certificate, or create a key and server certificate valid for specified IPs and host names, signed by a specified CA. To create a server certificate for the registry service IP and the docker-registry.default.svc.cluster.local host name:

    $ oadm ca create-server-cert \
        --signer-cert=/etc/origin/master/ca.crt \
        --signer-key=/etc/origin/master/ca.key \
        --signer-serial=/etc/origin/master/ca.serial.txt \
        --hostnames='docker-registry.default.svc.cluster.local,172.30.124.220' \
        --cert=/etc/secrets/registry.crt \
        --key=/etc/secrets/registry.key

    If the router will be exposed externally, add the public route host name in the --hostnames flag:

    --hostnames='mydocker-registry.example.com,docker-registry.default.svc.cluster.local,172.30.124.220

    See Redeploying Registry and Router Certificates for additional details on updating the default certificate so that the route is externally accessible.

    Note

    The oadm ca create-server-cert command generates a certificate that is valid for two years. This can be altered with the --expire-days option, but for security reasons, it is recommended to not make it greater than this value.

  4. Create the secret for the registry certificates:

    $ oc secrets new registry-certificates \
        /etc/secrets/registry.crt \
        /etc/secrets/registry.key
  5. Add the secret to the registry pod’s service accounts (including the default service account):

    $ oc secrets link registry registry-certificates
    $ oc secrets link default  registry-certificates
    Note

    Limiting secrets to only the service accounts that reference them is disabled by default. This means that if serviceAccountConfig.limitSecretReferences is set to false (the default setting) in the master configuration file, linking secrets to a service is not required.

  6. Pause the docker-registry service:

    $ oc rollout pause dc/docker-registry
  7. Add the secret volume to the registry deployment configuration:

    $ oc volume dc/docker-registry --add --type=secret \
        --secret-name=registry-certificates -m /etc/secrets
  8. Enable TLS by adding the following environment variables to the registry deployment configuration:

    $ oc set env dc/docker-registry \
        REGISTRY_HTTP_TLS_CERTIFICATE=/etc/secrets/registry.crt \
        REGISTRY_HTTP_TLS_KEY=/etc/secrets/registry.key

    See more details on overriding registry options.

  9. Update the scheme used for the registry’s liveness probe from HTTP to HTTPS:

    $ oc patch dc/docker-registry -p '{"spec": {"template": {"spec": {"containers":[{
        "name":"registry",
        "livenessProbe":  {"httpGet": {"scheme":"HTTPS"}}
      }]}}}}'
  10. If your registry was initially deployed on OpenShift Container Platform 3.2 or later, update the scheme used for the registry’s readiness probe from HTTP to HTTPS:

    $ oc patch dc/docker-registry -p '{"spec": {"template": {"spec": {"containers":[{
        "name":"registry",
        "readinessProbe":  {"httpGet": {"scheme":"HTTPS"}}
      }]}}}}'
  11. Resume the docker-registry service:

    $ oc rollout resume dc/docker-registry
  12. Validate the registry is running in TLS mode. Wait until the latest docker-registry deployment completes and verify the Docker logs for the registry container. You should find an entry for listening on :5000, tls.

    $ oc logs dc/docker-registry | grep tls
    time="2015-05-27T05:05:53Z" level=info msg="listening on :5000, tls" instance.id=deeba528-c478-41f5-b751-dc48e4935fc2
  13. Copy the CA certificate to the Docker certificates directory. This must be done on all nodes in the cluster:

    $ dcertsdir=/etc/docker/certs.d
    $ destdir_addr=$dcertsdir/172.30.124.220:5000
    $ destdir_name=$dcertsdir/docker-registry.default.svc.cluster.local:5000
    
    $ sudo mkdir -p $destdir_addr $destdir_name
    $ sudo cp ca.crt $destdir_addr    1
    $ sudo cp ca.crt $destdir_name
    1
    The ca.crt file is a copy of /etc/origin/master/ca.crt on the master.
  14. When using authentication, some versions of docker also require you to configure your cluster to trust the certificate at the OS level.

    1. Copy the certificate:

      $ cp /etc/origin/master/ca.crt /etc/pki/ca-trust/source/anchors/myregistrydomain.com.crt
    2. Run:

      $ update-ca-trust enable
  15. Remove the --insecure-registry option only for this particular registry in the /etc/sysconfig/docker file. Then, reload the daemon and restart the docker service to reflect this configuration change:

    $ sudo systemctl daemon-reload
    $ sudo systemctl restart docker
  16. Validate the docker client connection. Running docker push to the registry or docker pull from the registry should succeed. Make sure you have logged into the registry.

    $ docker tag|push <registry/image> <internal_registry/project/image>

    For example:

    $ docker pull busybox
    $ docker tag docker.io/busybox 172.30.124.220:5000/openshift/busybox
    $ docker push 172.30.124.220:5000/openshift/busybox
    ...
    cf2616975b4a: Image successfully pushed
    Digest: sha256:3662dd821983bc4326bee12caec61367e7fb6f6a3ee547cbaff98f77403cab55

3.4.3. Manually Exposing a Secure Registry

Instead of logging in to the OpenShift Container Registry from within the OpenShift Container Platform cluster, you can gain external access to it by first securing the registry and then exposing it with a route. This allows you to log in to the registry from outside the cluster using the route address, and to tag and push images using the route host.

  1. Each of the following prerequisite steps are performed by default during a typical cluster installation. If they have not been, perform them manually:

  2. A passthrough route should have been created by default for the registry during the initial cluster installation:

    1. Verify whether the route exists:

      $ oc get route/docker-registry -o yaml
      apiVersion: v1
      kind: Route
      metadata:
        name: docker-registry
      spec:
        host: <host> 1
        to:
          kind: Service
          name: docker-registry 2
        tls:
          termination: passthrough 3
      1
      The host for your route. You must be able to resolve this name externally via DNS to the router’s IP address.
      2
      The service name for your registry.
      3
      Specifies this route as a passthrough route.
      Note

      Passthrough is currently the only type of route supported for exposing the secure registry.

    2. If it does not exist, create the route via the oc create route passthrough command, specifying the registry as the route’s service. By default, the name of the created route is the same as the service name:

      1. Get the docker-registry service details:

        $ oc get svc
        NAME              CLUSTER_IP       EXTERNAL_IP   PORT(S)                 SELECTOR                  AGE
        docker-registry   172.30.69.167    <none>        5000/TCP                docker-registry=default   4h
        kubernetes        172.30.0.1       <none>        443/TCP,53/UDP,53/TCP   <none>                    4h
        router            172.30.172.132   <none>        80/TCP                  router=router             4h
      2. Create the route:

        $ oc create route passthrough    \
            --service=docker-registry    \1
            --hostname=<host>
        route "docker-registry" created     2
        1
        Specifies the registry as the route’s service.
        2
        The route name is identical to the service name.
  3. Next, you must trust the certificates being used for the registry on your host system. The certificates referenced were created when you secured your registry.

    $ sudo mkdir -p /etc/docker/certs.d/<host>
    $ sudo cp <ca_certificate_file> /etc/docker/certs.d/<host>
    $ sudo systemctl restart docker
  4. Log in to the registry using the information from securing the registry. However, this time point to the host name used in the route rather than your service IP. When logging in to a secured and exposed registry, make sure you specify the registry in the docker login command:

    # docker login -e user@company.com \
        -u f83j5h6 \
        -p Ju1PeM47R0B92Lk3AZp-bWJSck2F7aGCiZ66aFGZrs2 \
        <host>
  5. You can now tag and push images using the route host. For example, to tag and push a busybox image in a project called test:

    $ oc get imagestreams -n test
    NAME      DOCKER REPO   TAGS      UPDATED
    
    $ docker pull busybox
    $ docker tag busybox <host>/test/busybox
    $ docker push <host>/test/busybox
    The push refers to a repository [<host>/test/busybox] (len: 1)
    8c2e06607696: Image already exists
    6ce2e90b0bc7: Image successfully pushed
    cf2616975b4a: Image successfully pushed
    Digest: sha256:6c7e676d76921031532d7d9c0394d0da7c2906f4cb4c049904c4031147d8ca31
    
    $ docker pull <host>/test/busybox
    latest: Pulling from <host>/test/busybox
    cf2616975b4a: Already exists
    6ce2e90b0bc7: Already exists
    8c2e06607696: Already exists
    Digest: sha256:6c7e676d76921031532d7d9c0394d0da7c2906f4cb4c049904c4031147d8ca31
    Status: Image is up to date for <host>/test/busybox:latest
    
    $ oc get imagestreams -n test
    NAME      DOCKER REPO                       TAGS      UPDATED
    busybox   172.30.11.215:5000/test/busybox   latest    2 seconds ago
    Note

    Your image streams will have the IP address and port of the registry service, not the route name and port. See oc get imagestreams for details.

3.4.4. Manually Exposing a Non-Secure Registry

Instead of securing the registry in order to expose the registry, you can simply expose a non-secure registry for non-production OpenShift Container Platform environments. This allows you to have an external route to the registry without using SSL certificates.

Warning

Only non-production environments should expose a non-secure registry to external access.

To expose a non-secure registry:

  1. Expose the registry:

    # oc expose service docker-registry --hostname=<hostname> -n default

    This creates the following JSON file:

    apiVersion: v1
    kind: Route
    metadata:
      creationTimestamp: null
      labels:
        docker-registry: default
      name: docker-registry
    spec:
      host: registry.example.com
      port:
        targetPort: "5000"
      to:
        kind: Service
        name: docker-registry
    status: {}
  2. Verify that the route has been created successfully:

    # oc get route
    NAME              HOST/PORT                    PATH      SERVICE           LABELS                    INSECURE POLICY   TLS TERMINATION
    docker-registry   registry.example.com            docker-registry   docker-registry=default
  3. Check the health of the registry:

    $ curl -v http://registry.example.com/healthz

    Expect an HTTP 200/OK message.

    After exposing the registry, update your /etc/sysconfig/docker file by adding the port number to the OPTIONS entry. For example:

    OPTIONS='--selinux-enabled --insecure-registry=172.30.0.0/16 --insecure-registry registry.example.com:80'
    Important

    The above options should be added on the client from which you are trying to log in.

    Also, ensure that Docker is running on the client.

When logging in to the non-secured and exposed registry, make sure you specify the registry in the docker login command. For example:

# docker login -e user@company.com \
    -u f83j5h6 \
    -p Ju1PeM47R0B92Lk3AZp-bWJSck2F7aGCiZ66aFGZrs2 \
    <host>

3.5. Extended Registry Configuration

3.5.1. Maintaining the Registry IP Address

OpenShift Container Platform refers to the integrated registry by its service IP address, so if you decide to delete and recreate the docker-registry service, you can ensure a completely transparent transition by arranging to re-use the old IP address in the new service. If a new IP address cannot be avoided, you can minimize cluster disruption by rebooting only the masters.

Re-using the Address
To re-use the IP address, you must save the IP address of the old docker-registry service prior to deleting it, and arrange to replace the newly assigned IP address with the saved one in the new docker-registry service.
  1. Make a note of the clusterIP for the service:

    $ oc get svc/docker-registry -o yaml | grep clusterIP:
  2. Delete the service:

    $ oc delete svc/docker-registry dc/docker-registry
  3. Create the registry definition in registry.yaml, replacing <options> with, for example, those used in step 3 of the instructions in the Non-Production Use section:

    $ oadm registry <options> -o yaml > registry.yaml
  4. Edit registry.yaml, find the Service there, and change its clusterIP to the address noted in step 1.
  5. Create the registry using the modified registry.yaml:

    $ oc create -f registry.yaml
Rebooting the Masters

If you are unable to re-use the IP address, any operation that uses a pull specification that includes the old IP address will fail. To minimize cluster disruption, you must reboot the masters:

# systemctl restart atomic-openshift-master

This ensures that the old registry URL, which includes the old IP address, is cleared from the cache.

Note

We recommend against rebooting the entire cluster because that incurs unnecessary downtime for pods and does not actually clear the cache.

3.5.2. Whitelisting Docker Registries

You can specify a whitelist of docker registries, allowing you to curate a set of images and templates that are available for download by OpenShift Container Platform users. This curated set can be placed in one or more docker registries, and then added to the whitelist. When using a whitelist, only the specified registries are accessible within OpenShift Container Platform, and all other registries are denied access by default.

To configure a whitelist:

  1. Edit the /etc/sysconfig/docker file to block all registries:

    BLOCK_REGISTRY='--block-registry=all'

    You may need to uncomment the BLOCK_REGISTRY line.

  2. In the same file, add registries to which you want to allow access:

    ADD_REGISTRY='--add-registry=<registry1> --add-registry=<registry2>'

    Allowing Access to Registries

    ADD_REGISTRY='--add-registry=registry.access.redhat.com'

    This example would restrict access to images available on the Red Hat Customer Portal.

Once the whitelist is configured, if a user tries to pull from a docker registry that is not on the whitelist, they will receive an error message stating that this registry is not allowed.

3.5.3. Setting the Registry Hostname

You can configure the hostname and port the registry is known by for both internal and external references. By doing this, image streams will provide hostname based push and pull specifications for images, allowing consumers of the images to be isolated from changes to the registry service ip and potentially allowing image streams and their references to be portable between clusters.

To set the hostname used to reference the registry from within the cluster, set the internalRegistryHostname in the imagePolicyConfig section of the master configuration file. The external hostname is controlled by setting the externalRegistryHostname value in the same location.

Image Policy Configuration

imagePolicyConfig:
  internalRegistryHostname: docker-registry.default.svc.cluster.local:5000
  externalRegistryHostname: docker-registry.mycompany.com

Note

If you have enabled TLS for your registry the server certificate must include the hostnames by which you expect the registry to be referenced. See securing the registry for instructions on adding hostnames to the server certificate.

3.5.4. Overriding the Registry Configuration

You can override the integrated registry’s default configuration, found by default at /config.yml in a running registry’s container, with your own custom configuration.

Note

Upstream configuration options in this file may also be overridden using environment variables. The middleware section is an exception as there are just a few options that can be overridden using environment variables. Learn how to override specific configuration options.

To enable management of the registry configuration file directly and deploy an updated configuration using a ConfigMap:

  1. Deploy the registry.
  2. Edit the registry configuration file locally as needed. The initial YAML file deployed on the registry is provided below. Review supported options.

    Registry Configuration File

    version: 0.1
    log:
      level: debug
    http:
      addr: :5000
    storage:
      cache:
        blobdescriptor: inmemory
      filesystem:
        rootdirectory: /registry
      delete:
        enabled: true
    auth:
      openshift:
        realm: openshift
    middleware:
      registry:
        - name: openshift
      repository:
        - name: openshift
          options:
            acceptschema2: true
            pullthrough: true
            enforcequota: false
            projectcachettl: 1m
            blobrepositorycachettl: 10m
      storage:
        - name: openshift
    openshift:
      version: 1.0
      metrics:
        enabled: false
        secret: <secret>

  3. Create a ConfigMap holding the content of each file in this directory:

    $ oc create configmap registry-config \
        --from-file=</path/to/custom/registry/config.yml>/
  4. Add the registry-config ConfigMap as a volume to the registry’s deployment configuration to mount the custom configuration file at /etc/docker/registry/:

    $ oc volume dc/docker-registry --add --type=configmap \
        --configmap-name=registry-config -m /etc/docker/registry/
  5. Update the registry to reference the configuration path from the previous step by adding the following environment variable to the registry’s deployment configuration:

    $ oc set env dc/docker-registry \
        REGISTRY_CONFIGURATION_PATH=/etc/docker/registry/config.yml

This may be performed as an iterative process to achieve the desired configuration. For example, during troubleshooting, the configuration may be temporarily updated to put it in debug mode.

To update an existing configuration:

Warning

This procedure will overwrite the currently deployed registry configuration.

  1. Edit the local registry configuration file, config.yml.
  2. Delete the registry-config secret:

    $ oc delete secret registry-config
  3. Recreate the secret to reference the updated configuration file:

    $ oc secrets new registry-config config.yml=</path/to/custom/registry/config.yml>
  4. Redeploy the registry to read the updated configuration:

    $ oc rollout latest docker-registry
Tip

Maintain configuration files in a source control repository.

3.5.5. Registry Configuration Reference

There are many configuration options available in the upstream docker distribution library. Not all configuration options are supported or enabled. Use this section as a reference when overriding the registry configuration.

Note

Upstream configuration options in this file may also be overridden using environment variables. However, the middleware section may not be overridden using environment variables. Learn how to override specific configuration options.

3.5.5.1. Log

Upstream options are supported.

Example:

log:
  level: debug
  formatter: text
  fields:
    service: registry
    environment: staging

3.5.5.2. Hooks

Mail hooks are not supported.

3.5.5.3. Storage

This section lists the supported registry storage drivers.

The following list includes storage drivers that need to be configured in the registry’s configuration file:

General registry storage configuration options are supported.

The following storage options need to be configured through the filesystem driver:

Note

For more information on supported persistent storage drivers, see Configuring Persistent Storage and Persistent Storage Examples.

General Storage Configuration Options

storage:
  delete:
    enabled: true 1
  redirect:
    disable: false
  cache:
    blobdescriptor: inmemory
  maintenance:
    uploadpurging:
      enabled: true
      age: 168h
      interval: 24h
      dryrun: false
    readonly:
      enabled: false

1
This entry is mandatory for image pruning to work properly.

3.5.5.4. Auth

Auth options should not be altered. The openshift extension is the only supported option.

auth:
  openshift:
    realm: openshift

3.5.5.5. Middleware

The repository middleware extension allows to configure OpenShift Container Platform middleware responsible for interaction with OpenShift Container Platform and image proxying.

middleware:
  registry:
    - name: openshift 1
  repository:
    - name: openshift 2
      options:
        acceptschema2: true 3
        pullthrough: true 4
        mirrorpullthrough: true 5
        enforcequota: false 6
        projectcachettl: 1m 7
        blobrepositorycachettl: 10m 8
  storage:
    - name: openshift 9
1 2 9
These entries are mandatory. Their presence ensures required components are loaded. These values should not be changed.
3
Allows you to store manifest schema v2 during a push to the registry. See below for more details.
4
Allows the registry to act as a proxy for remote blobs. See below for more details.
5
Allows the registry cache blobs to be served from remote registries for fast access later. The mirroring starts when the blob is accessed for the first time. The option has no effect if the pullthrough is disabled.
6
Prevents blob uploads exceeding the size limit, which are defined in the targeted project.
7
An expiration timeout for limits cached in the registry. The lower the value, the less time it takes for the limit changes to propagate to the registry. However, the registry will query limits from the server more frequently and, as a consequence, pushes will be slower.
8
An expiration timeout for remembered associations between blob and repository. The higher the value, the higher probability of fast lookup and more efficient registry operation. On the other hand, memory usage will raise as well as a risk of serving image layer to user, who is no longer authorized to access it.
3.5.5.5.1. CloudFront Middleware

The CloudFront middleware extension can be added to support AWS, CloudFront CDN storage provider. CloudFront middleware speeds up distribution of image content internationally. The blobs are distributed to several edge locations around the world. The client is always directed to the edge with the lowest latency.

Note

The CloudFront middleware extension can be only used with S3 storage. It is utilized only during blob serving. Therefore, only blob downloads can be speeded up, not uploads.

The following is an example of minimal configuration of S3 storage driver with a CloudFront middleware:

version: 0.1
log:
  level: debug
http:
  addr: :5000
storage:
  cache:
    blobdescriptor: inmemory
  delete:
    enabled: true
  s3: 1
    accesskey: BJKMSZBRESWJQXRWMAEQ
    secretkey: 5ah5I91SNXbeoUXXDasFtadRqOdy62JzlnOW1goS
    region: us-east-1
    bucket: docker.myregistry.com
auth:
  openshift:
    realm: openshift
middleware:
  registry:
    - name: openshift
  repository:
    - name: openshift
   storage:
    - name: cloudfront 2
      options:
        baseurl: https://jrpbyn0k5k88bi.cloudfront.net/ 3
        privatekey: /etc/docker/cloudfront-ABCEDFGHIJKLMNOPQRST.pem 4
        keypairid: ABCEDFGHIJKLMNOPQRST 5
    - name: openshift
1
The S3 storage must be configured the same way regardless of CloudFront middleware.
2
The CloudFront storage middleware needs to be listed before OpenShift middleware.
3
The CloudFront base URL. In the AWS management console, this is listed as Domain Name of CloudFront distribution.
4
The location of your AWS private key on the filesystem. This must be not confused with Amazon EC2 key pair. Please refer to AWS documentation on creating CloudFront key pairs for your trusted signers. The file needs to be mounted as a secret secret into the registry pod.
5
The ID of your Cloudfront key pair.
3.5.5.5.2. Overriding Middleware Configuration Options

The middleware section cannot be overridden using environment variables. There are a few exceptions, however. For example:

middleware:
  repository:
    - name: openshift
      options:
        acceptschema2: true 1
        pullthrough: true 2
        mirrorpullthrough: true 3
        enforcequota: false 4
        projectcachettl: 1m 5
        blobrepositorycachettl: 10m 6
1
A configuration option that can be overridden by the boolean environment variable REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ACCEPTSCHEMA2, which allows for the ability to accept manifest schema v2 on manifest put requests. Recognized values are true and false (which applies to all the other boolean variables below).
2
A configuration option that can be overridden by the boolean environment variable REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_PULLTHROUGH, which enables a proxy mode for remote repositories.
3
A configuration option that can be overridden by the boolean environment variable REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_MIRRORPULLTHROUGH, which instructs registry to mirror blobs locally if serving remote blobs.
4
A configuration option that can be overridden by the boolean environment variable REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ENFORCEQUOTA, which allows the ability to turn quota enforcement on or off. By default, quota enforcement is off.
5
A configuration option that can be overridden by the environment variable REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_PROJECTCACHETTL, specifying an eviction timeout for project quota objects. It takes a valid time duration string (for example, 2m). If empty, you get the default timeout. If zero (0m), caching is disabled.
6
A configuration option that can be overridden by the environment variable REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_BLOBREPOSITORYCACHETTL, specifying an eviction timeout for associations between blob and containing repository. The format of the value is the same as in projectcachettl case.
3.5.5.5.3. Image Pullthrough

If enabled, the registry will attempt to fetch requested blob from a remote registry unless the blob exists locally. The remote candidates are calculated from DockerImage entries stored in status of the image stream, a client pulls from. All the unique remote registry references in such entries will be tried in turn until the blob is found.

Pullthrough will only occur if an image stream tag exists for the image being pulled. For example, if the image being pulled is docker-registry.default.svc:5000/yourproject/yourimage:prod then the registry will look for an image stream tag named yourimage:prod in the project yourproject. If it finds one, it will attempt to pull the image using the dockerImageReference associated with that image stream tag.

When performing pullthrough, the registry will use pull credentials found in the project associated with the image stream tag that is being referenced. This capability also makes it possible for you to pull images that reside on a registry they do not have credentials to access, as long as you have access to the image stream tag that references the image.

Note that by default image stream tags use a reference policy type of Source which means that when the image stream reference is resolved to an image pull specification, the specification used will point to the source of the image. For images hosted on external registries, this will be the external registry and as a result the resource will reference and pull the image by the external registry. For example, registry.access.redhat.com/openshift3/jenkins-2-rhel7 and pullthrough will not apply. To ensure that resources referencing image streams use a pull specification that points to the internal registry, the image stream tag should use a reference policy type of Local. More information is available on Reference Policy.

This feature is on by default. However, it can be disabled using a configuration option.

By default, all the remote blobs served this way are stored locally for subsequent faster access unless mirrorpullthrough is disabled. The downside of this mirroring feature is an increased storage usage.

Note

The mirroring starts when a client tries to fetch at least a single byte of the blob. To pre-fetch a particular image into integrated registry before it is actually needed, you can run the following command:

$ oc get imagestreamtag/${IS}:${TAG} -o jsonpath='{ .image.dockerImageLayers[*].name }' | \
  xargs -n1 -I {} curl -H "Range: bytes=0-1" -u user:${TOKEN} \
  http://${REGISTRY_IP}:${PORT}/v2/default/mysql/blobs/{}
Note

This OpenShift Container Platform mirroring feature should not be confused with the upstream registry pull through cache feature, which is a similar but distinct capability.

3.5.5.5.4. Manifest Schema v2 Support

Each image has a manifest describing its blobs, instructions for running it and additional metadata. The manifest is versioned, with each version having different structure and fields as it evolves over time. The same image can be represented by multiple manifest versions. Each version will have different digest though.

The registry currently supports manifest v2 schema 1 (schema1) and manifest v2 schema 2 (schema2). The former is being obsoleted but will be supported for an extended amount of time.

You should be wary of compatibility issues with various Docker clients:

  • Docker clients of version 1.9 or older support only schema1. Any manifest this client pulls or pushes will be of this legacy schema.
  • Docker clients of version 1.10 support both schema1 and schema2. And by default, it will push the latter to the registry if it supports newer schema.

The registry, storing an image with schema1 will always return it unchanged to the client. Schema2 will be transferred unchanged only to newer Docker client. For the older one, it will be converted on-the-fly to schema1.

This has significant consequences. For example an image pushed to the registry by a newer Docker client cannot be pulled by the older Docker by its digest. That’s because the stored image’s manifest is of schema2 and its digest can be used to pull only this version of manifest.

For this reason, the registry is configured by default not to store schema2. This ensures that any docker client will be able to pull from the registry any image pushed there regardless of client’s version.

Once you’re confident that all the registry clients support schema2, you’ll be safe to enable its support in the registry. See the middleware configuration reference above for particular option.

3.5.5.6. OpenShift

This section reviews the configuration of global settings for features specific to OpenShift Container Platform. In a future release, openshift-related settings in the Middleware section will be obsoleted.

Currently, this section allows you to configure registry metrics collection:

openshift:
  version: 1.0 1
  metrics:
    enabled: false 2
    secret: <secret> 3
  requests:
    read:
      maxrunning: 10 4
      maxinqueue: 10 5
      maxwaitinqueue 2m 6
    write:
      maxrunning: 10 7
      maxinqueue: 10 8
      maxwaitinqueue 2m 9
1
A mandatory entry specifying configuration version of this section. The only supported value is 1.0.
2
Can be set to true to enable metrics collection. The same can be achieved using the boolean environment variable REGISTRY_OPENSHIFT_METRICS_ENABLED=true.
3
A secret used to authorize client requests. Metrics clients must use it as a bearer token in Authorization header. It can be overridden by the environment variable REGISTRY_OPENSHIFT_METRICS_SECRET.
4
Maximum number of simultaneous pull requests. It can be overridden by the environment variable REGISTRY_OPENSHIFT_REQUESTS_READ_MAXRUNNING. Zero indicates no limit.
5
Maximum number of queued pull requests. It can be overridden by the environment variable REGISTRY_OPENSHIFT_REQUESTS_READ_MAXINQUEUE. Zero indicates no limit.
6
Maximum time a pull request can wait in the queue before being rejected. It can be overridden by the environment variable REGISTRY_OPENSHIFT_REQUESTS_READ_MAXWAITINQUEUE. Zero indicates no limit.
7
Maximum number of simultaneous push requests. It can be overridden by the environment variable REGISTRY_OPENSHIFT_REQUESTS_WRITE_MAXRUNNING. Zero indicates no limit.
8
Maximum number of queued push requests. It can be overridden by the environment variable REGISTRY_OPENSHIFT_REQUESTS_WRITE_MAXINQUEUE. Zero indicates no limit.
9
Maximum time a push request can wait in the queue before being rejected. It can be overridden by the environment variable REGISTRY_OPENSHIFT_REQUESTS_WRITE_MAXWAITINQUEUE. Zero indicates no limit.

See Accessing Registry Metrics for usage information.

3.5.5.7. Reporting

Reporting is unsupported.

3.5.5.8. HTTP

Upstream options are supported. Learn how to alter these settings via environment variables. Only the tls section should be altered. For example:

http:
  addr: :5000
  tls:
    certificate: /etc/secrets/registry.crt
    key: /etc/secrets/registry.key

3.5.5.9. Notifications

Upstream options are supported. The REST API Reference provides more comprehensive integration options.

Example:

notifications:
  endpoints:
    - name: registry
      disabled: false
      url: https://url:port/path
      headers:
        Accept:
          - text/plain
      timeout: 500
      threshold: 5
      backoff: 1000

3.5.5.10. Redis

Redis is not supported.

3.5.5.11. Health

Upstream options are supported. The registry deployment configuration provides an integrated health check at /healthz.

3.5.5.12. Proxy

Proxy configuration should not be enabled. This functionality is provided by the OpenShift Container Platform repository middleware extension, pullthrough: true.

3.6. Known Issues

3.6.1. Overview

The following are the known issues when deploying or using the integrated registry.

3.6.2. Image Push Errors with Scaled Registry Using Shared NFS Volume

When using a scaled registry with a shared NFS volume, you may see one of the following errors during the push of an image:

  • digest invalid: provided digest did not match uploaded content
  • blob upload unknown
  • blob upload invalid

These errors are returned by an internal registry service when Docker attempts to push the image. Its cause originates in the synchronization of file attributes across nodes. Factors such as NFS client side caching, network latency, and layer size can all contribute to potential errors that might occur when pushing an image using the default round-robin load balancing configuration.

You can perform the following steps to minimize the probability of such a failure:

  1. Ensure that the sessionAffinity of your docker-registry service is set to ClientIP:

    $ oc get svc/docker-registry --template='{{.spec.sessionAffinity}}'

    This should return ClientIP, which is the default in recent OpenShift Container Platform versions. If not, change it:

    $ oc patch svc/docker-registry -p '{"spec":{"sessionAffinity": "ClientIP"}}'
  2. Ensure that the NFS export line of your registry volume on your NFS server has the no_wdelay options listed. The no_wdelay option prevents the server from delaying writes, which greatly improves read-after-write consistency, a requirement of the registry.
Note

The guidelines for NFS are recommended to help you get started. You may switch off from NFS when moving to production.

3.6.3. Pull of Internally Managed Image Fails with "not found" Error

This error occurs when the pulled image is pushed to an image stream different from the one it is being pulled from. This is caused by re-tagging a built image into an arbitrary image stream:

$ oc tag srcimagestream:latest anyproject/pullimagestream:latest

And subsequently pulling from it, using an image reference such as:

internal.registry.url:5000/anyproject/pullimagestream:latest

During a manual Docker pull, this will produce a similar error:

Error: image anyproject/pullimagestream:latest not found

To prevent this, avoid the tagging of internally managed images completely, or re-push the built image to the desired namespace manually.

3.6.4. Image Push Fails with "500 Internal Server Error" on S3 Storage

There are problems reported happening when the registry runs on S3 storage back-end. Pushing to a Docker registry occasionally fails with the following error:

Received unexpected HTTP status: 500 Internal Server Error

To debug this, you need to view the registry logs. In there, look for similar error messages occurring at the time of the failed push:

time="2016-03-30T15:01:21.22287816-04:00" level=error msg="unknown error completing upload: driver.Error{DriverName:\"s3\", Enclosed:(*url.Error)(0xc20901cea0)}" http.request.method=PUT
...
time="2016-03-30T15:01:21.493067808-04:00" level=error msg="response completed with error" err.code=UNKNOWN err.detail="s3: Put https://s3.amazonaws.com/oso-tsi-docker/registry/docker/registry/v2/blobs/sha256/ab/abe5af443833d60cf672e2ac57589410dddec060ed725d3e676f1865af63d2e2/data: EOF" err.message="unknown error" http.request.method=PUT
...
time="2016-04-02T07:01:46.056520049-04:00" level=error msg="error putting into main store: s3: The request signature we calculated does not match the signature you provided. Check your key and signing method." http.request.method=PUT
atest

If you see such errors, contact your Amazon S3 support. There may be a problem in your region or with your particular bucket.

3.6.5. Image Pruning Fails

If you encounter the following error when pruning images:

BLOB sha256:49638d540b2b62f3b01c388e9d8134c55493b1fa659ed84e97cb59b87a6b8e6c error deleting blob

And your registry log contains the following information:

error deleting blob \"sha256:49638d540b2b62f3b01c388e9d8134c55493b1fa659ed84e97cb59b87a6b8e6c\": operation unsupported

It means that your custom configuration file lacks mandatory entries in the storage section, namely storage:delete:enabled set to true. Add them, re-deploy the registry, and repeat your image pruning operation.

Chapter 4. Setting up a Router

4.1. Router Overview

4.1.1. About Routers

There are many ways to get traffic into the cluster. The most common approach is to use the OpenShift Container Platform router as the ingress point for external traffic destined for services in your OpenShift Container Platform installation.

OpenShift Container Platform provides and supports the following router plug-ins:

  • The HAProxy template router is the default plug-in. It uses the openshift3/ose-haproxy-router image to run an HAProxy instance alongside the template router plug-in inside a container on OpenShift Container Platform. It currently supports HTTP(S) traffic and TLS-enabled traffic via SNI. The router’s container listens on the host network interface, unlike most containers that listen only on private IPs. The router proxies external requests for route names to the IPs of actual pods identified by the service associated with the route.
  • The F5 router integrates with an existing F5 BIG-IP® system in your environment to synchronize routes. F5 BIG-IP® version 11.4 or newer is required in order to have the F5 iControl REST API.
Note

The F5 router plug-in is available starting in OpenShift Container Platform 3.0.2.

4.1.2. Router Service Account

Before deploying an OpenShift Container Platform cluster, you must have a service account for the router. Starting in OpenShift Container Platform 3.1, a router service account is automatically created during a quick or advanced installation (previously, this required manual creation). This service account has permissions to a security context constraint (SCC) that allows it to specify host ports.

4.1.2.1. Permission to Access Labels

When namespace labels are used, for example in creating router shards, the service account for the router must have cluster-reader permission.

$ oadm policy add-cluster-role-to-user \
    cluster-reader \
    system:serviceaccount:default:router

With a service account in place, you can proceed to installing a default HAProxy Router, a customized HAProxy Router or F5 Router.

4.2. Using the Default HAProxy Router

4.2.1. Overview

The oc adm router command is provided with the administrator CLI to simplify the tasks of setting up routers in a new installation. If you followed the quick installation, then a default router was automatically created for you. The oc adm router command creates the service and deployment configuration objects. Use the --service-account option to specify the service account the router will use to contact the master.

The router service account can be created in advance or created by the oc adm router --service-account command.

Every form of communication between OpenShift Container Platform components is secured by TLS and uses various certificates and authentication methods. The --default-certificate .pem format file can be supplied or one is created by the oc adm router command. When routes are created, the user can provide route certificates that the router will use when handling the route.

Important

When deleting a router, ensure the deployment configuration, service, and secret are deleted as well.

Routers are deployed on specific nodes. This makes it easier for the cluster administrator and external network manager to coordinate which IP address will run a router and which traffic the router will handle. The routers are deployed on specific nodes by using node selectors.

Important

Routers use host networking by default, and they directly attach to port 80 and 443 on all interfaces on a host. Restrict routers to hosts where ports 80/443 are available and not being consumed by another service, and set this using node selectors and the scheduler configuration. As an example, you can achieve this by dedicating infrastructure nodes to run services such as routers.

Important

It is recommended to use separate distinct openshift-router service account with your router. This can be provided using the --service-account flag to the oc adm router command.

$ oc adm router --dry-run --service-account=router 1
1
--service-account is the name of a service account for the openshift-router.
Important

Router pods created using oc adm router have default resource requests that a node must satisfy for the router pod to be deployed. In an effort to increase the reliability of infrastructure components, the default resource requests are used to increase the QoS tier of the router pods above pods without resource requests. The default values represent the observed minimum resources required for a basic router to be deployed and can be edited in the routers deployment configuration and you may want to increase them based on the load of the router.

4.2.2. Creating a Router

The quick installation process automatically creates a default router. If the router does not exist, run the following to create a router:

$ oc adm router <router_name> --replicas=<number> --service-account=router

--replicas is usually 1 unless a high availability configuration is being created.

To find the host IP address of the router:

$ oc get po <router-pod>  --template={{.status.hostIP}}

You can also use router shards to ensure that the router is filtered to specific namespaces or routes, or set any environment variables after router creation. In this case create a router for each shard.

4.2.3. Other Basic Router Commands

Checking the Default Router
The default router service account, named router, is automatically created during quick and advanced installations. To verify that this account already exists:
$ oc adm router --dry-run --service-account=router
Viewing the Default Router
To see what the default router would look like if created:
$ oc adm router --dry-run -o yaml --service-account=router
Deploying the Router to a Labeled Node
To deploy the router to any node(s) that match a specified node label:
$ oc adm router <router_name> --replicas=<number> --selector=<label> \
    --service-account=router

For example, if you want to create a router named router and have it placed on a node labeled with region=infra:

$ oc adm router router --replicas=1 --selector='region=infra' \
  --service-account=router

During advanced installation, the openshift_hosted_router_selector and openshift_registry_selector Ansible settings are set to region=infra by default. The default router and registry will only be automatically deployed if a node exists that matches the region=infra label.

Multiple instances are created on different hosts according to the scheduler policy.

Using a Different Router Image
To use a different router image and view the router configuration that would be used:
$ oc adm router <router_name> -o <format> --images=<image> \
    --service-account=router

For example:

$ oc adm router region-west -o yaml --images=myrepo/somerouter:mytag \
    --service-account=router

4.2.4. Filtering Routes to Specific Routers

Using the ROUTE_LABELS environment variable, you can filter routes so that they are used only by specific routers.

For example, if you have multiple routers, and 100 routes, you can attach labels to the routes so that a portion of them are handled by one router, whereas the rest are handled by another.

  1. After creating a router, use the ROUTE_LABELS environment variable to tag the router:

    $ oc env dc/<router=name>  ROUTE_LABELS="key=value"
  2. Add the label to the desired routes:

    oc label route <route=name> key=value
  3. To verify that the label has been attached to the route, check the route configuration:

    $ oc describe dc/<route_name>
Setting the Maximum Number of Concurrent Connections
The router can handle a maximum number of 20000 connections by default. You can change that limit depending on your needs. Having too few connections prevents the health check from working, which causes unnecessary restarts. You need to configure the system to support the maximum number of connections. The limits shown in 'sysctl fs.nr_open' and 'sysctl fs.file-max' must be large enough. Otherwise, HAproxy will not start.

When the router is created, the --max-connections= option sets the desired limit:

$ oc adm router --max-connections=10000   ....

Edit the ROUTER_MAX_CONNECTIONS environment variable in the router’s deployment configuration to change the value. The router pods are restarted with the new value. If ROUTER_MAX_CONNECTIONS is not present, the default value of 20000, is used.

4.2.5. HAProxy Strict SNI

The HAProxy strict-sni can be controlled through the ROUTER_STRICT_SNI environment variable in the router’s deployment configuration. It can also be set when the router is created by using the --strict-sni command line option.

$ oc adm router --strict-sni

4.2.6. TLS Cipher Suites

Set the router cipher suite using the --ciphers option when creating a router:

$ oc adm router --ciphers=modern   ....

The values are: modern, intermediate, or old, with intermediate as the default. Alternatively, a set of ":" separated ciphers can be provided. The ciphers must be from the set displayed by:

$ openssl ciphers

Alternatively, use the ROUTER_CIPHERS environment variable for an existing router.

4.2.7. Highly-Available Routers

You can set up a highly-available router on your OpenShift Container Platform cluster using IP failover. This setup has multiple replicas on different nodes so the failover software can switch to another replica if the current one fails.

4.2.8. Customizing the Router Service Ports

You can customize the service ports that a template router binds to by setting the environment variables ROUTER_SERVICE_HTTP_PORT and ROUTER_SERVICE_HTTPS_PORT. This can be done by creating a template router, then editing its deployment configuration.

The following example creates a router deployment with 0 replicas and customizes the router service HTTP and HTTPS ports, then scales it appropriately (to 1 replica).

$ oc adm router --replicas=0 --ports='10080:10080,10443:10443' 1
$ oc set env dc/router ROUTER_SERVICE_HTTP_PORT=10080  \
                   ROUTER_SERVICE_HTTPS_PORT=10443
$ oc scale dc/router --replicas=1
1
Ensures exposed ports are appropriately set for routers that use the container networking mode --host-network=false.
Important

If you do customize the template router service ports, you will also need to ensure that the nodes where the router pods run have those custom ports opened in the firewall (either via Ansible or iptables, or any other custom method that you use via firewall-cmd).

The following is an example using iptables to open the custom router service ports.

$ iptables -A INPUT -p tcp --dport 10080 -j ACCEPT
$ iptables -A INPUT -p tcp --dport 10443 -j ACCEPT

4.2.9. Working With Multiple Routers

An administrator can create multiple routers with the same definition to serve the same set of routes. Each router will be on a different node and will have a different IP address. The network administrator will need to get the desired traffic to each node.

Multiple routers can be grouped to distribute routing load in the cluster and separate tenants to different routers or shards. Each router or shard in the group admits routes based on the selectors in the router. An administrator can create shards over the whole cluster using ROUTE_LABELS. A user can create shards over a namespace (project) by using NAMESPACE_LABELS.

4.2.10. Adding a Node Selector to a Deployment Configuration

Making specific routers deploy on specific nodes requires two steps:

  1. Add a label to the desired node:

    $ oc label node 10.254.254.28 "router=first"
  2. Add a node selector to the router deployment configuration:

    $ oc edit dc <deploymentConfigName>

    Add the template.spec.nodeSelector field with a key and value corresponding to the label:

    ...
      template:
        metadata:
          creationTimestamp: null
          labels:
            router: router1
        spec:
          nodeSelector:      1
            router: "first"
    ...
    1
    The key and value are router and first, respectively, corresponding to the router=first label.

4.2.11. Using Router Shards

Router sharding uses NAMESPACE_LABELS and ROUTE_LABELS, to filter router namespaces and routes. This enables you to partition routes amongst multiple router deployments effectively distributing the set of routes.

By default, a router selects all routes from all projects (namespaces). Sharding adds labels to routes and each router shard selects routes with specific labels.

Note

The router service account must have the [cluster reader] permission set to allow access to labels in other namespaces.

Router Sharding and DNS

Because an external DNS server is needed to route requests to the desired shard, the administrator is responsible for making a separate DNS entry for each router in a project. A router will not forward unknown routes to another router.

For example:

  • If Router A lives on host 192.168.0.5 and has routes with *.foo.com.
  • And Router B lives on host 192.168.1.9 and has routes with *.example.com.

Separate DNS entries must resolve *.foo.com to the node hosting Router A and *.example.com to the node hosting Router B:

  • *.foo.com A IN 192.168.0.5
  • *.example.com A IN 192.168.1.9

Router Sharding Examples

This section describes router sharding using project (namespace) labels or project (namespace) names.

Figure 4.1. Router Sharding Based on Namespace Labels

Router Sharding Based on Namespace Labels

Example: A router deployment finops-router is run with route selector NAMESPACE_LABELS="name in (finance, ops)" and a router deployment dev-router is run with route selector NAMESPACE_LABELS="name=dev".

If all routes are in the three namespaces finance, ops or dev, then this could effectively distribute your routes across two router deployments.

In the above scenario, sharding becomes a special case of partitioning with no overlapping sets. Routes are divided amongst multiple router shards.

The criteria for route selection governs how the routes are distributed. It is possible to have routes that overlap across multiple router deployments.

Example: In addition to the finops-router and dev-router in the example above, you also have devops-router, which is run with a route selector NAMESPACE_LABELS="name in (dev, ops)".

The routes in namespaces dev or ops now are serviced by two different router deployments. This becomes a case in which you have partitioned the routes with an overlapping set.

In addition, this enables you to create more complex routing rules, allowing the diversion of high priority traffic to the dedicated finops-router, but sending the lower priority ones to the devops-router.

NAMESPACE_LABELS allows filtering of the projects to service and selecting all the routes from those projects, but you may want to partition routes based on other criteria in the routes themselves. The ROUTE_LABELS selector allows you to slice-and-dice the routes themselves.

Example: A router deployment prod-router is run with route selector ROUTE_LABELS="mydeployment=prod" and a router deployment devtest-router is run with route selector ROUTE_LABELS="mydeployment in (dev, test)".

The example assumes you have all the routes you want to be serviced tagged with a label "mydeployment=<tag>".

Figure 4.2. Router Sharding Based on Namespace Names

Router Sharding Based on Namespace Names

4.2.11.1. Creating Router Shards

To implement router sharding, set labels on the routes in the pool and express the desired subset of those routes for the router to admit with a selection expression via the oc set env command.

First, ensure that service account associated with the router has the cluster reader permission.

The rest of this section describes an extended example. Suppose there are 26 routes, named a — z, in the pool, with various labels:

Possible labels on routes in the pool

sla=high       geo=east     hw=modest     dept=finance
sla=medium     geo=west     hw=strong     dept=dev
sla=low                                   dept=ops

These labels express the concepts: service level agreement, geographical location, hardware requirements, and department. The routes in the pool can have at most one label from each column. Some routes may have other labels, entirely, or none at all.

Name(s)SLAGeoHWDeptOther Labels

a

high

east

modest

finance

type=static

b

 

west

strong

 

type=dynamic

c, d, e

low

 

modest

 

type=static

g — k

medium

 

strong

dev

 

l — s

high

 

modest

ops

 

t — z

 

west

  

type=dynamic

Here is a convenience script mkshard that ilustrates how oc adm router, oc set env, and oc scale work together to make a router shard.

#!/bin/bash
# Usage: mkshard ID SELECTION-EXPRESSION
id=$1
sel="$2"
router=router-shard-$id           1
oc adm router $router --replicas=0  2
dc=dc/router-shard-$id            3
oc set env   $dc ROUTE_LABELS="$sel"  4
oc scale $dc --replicas=3         5
1
The created router has name router-shard-<id>.
2
Specify no scaling for now.
3
The deployment configuration for the router.
4
Set the selection expression using oc set env. The selection expression is the value of the ROUTE_LABELS environment variable.
5
Scale it up.

Running mkshard several times creates several routers:

RouterSelection ExpressionRoutes

router-shard-1

sla=high

a, l — s

router-shard-2

geo=west

b, t — z

router-shard-3

dept=dev

g — k

4.2.11.2. Modifying Router Shards

Because a router shard is a construct based on labels, you can modify either the labels (via oc label) or the selection expression.

This section extends the example started in the Creating Router Shards section, demonstrating how to change the selection expression.

Here is a convenience script modshard that modifies an existing router to use a new selection expression:

#!/bin/bash
# Usage: modshard ID SELECTION-EXPRESSION...
id=$1
shift
router=router-shard-$id       1
dc=dc/$router                 2
oc scale $dc --replicas=0     3
oc set env   $dc "$@"             4
oc scale $dc --replicas=3     5
1
The modified router has name router-shard-<id>.
2
The deployment configuration where the modifications occur.
3
Scale it down.
4
Set the new selection expression using oc set env. Unlike mkshard from the Creating Router Shards section, the selection expression specified as the non-ID arguments to modshard must include the environment variable name as well as its value.
5
Scale it back up.
Note

In modshard, the oc scale commands are not necessary if the deployment strategy for router-shard-<id> is Rolling.

For example, to expand the department for router-shard-3 to include ops as well as dev:

$ modshard 3 ROUTE_LABELS='dept in (dev, ops)'

The result is that router-shard-3 now selects routes g — s (the combined sets of g — k and l — s).

This example takes into account that there are only three departments in this example scenario, and specifies a department to leave out of the shard, thus achieving the same result as the preceding example:

$ modshard 3 ROUTE_LABELS='dept != finanace'

This example specifies shows three comma-separated qualities, and results in only route b being selected:

$ modshard 3 ROUTE_LABELS='hw=strong,type=dynamic,geo=west'

Similarly to ROUTE_LABELS, which involve a route’s labels, you can select routes based on the labels of the route’s namespace labels, with the NAMESPACE_LABELS environment variable. This example modifies router-shard-3 to serve routes whose namespace has the label frequency=weekly:

$ modshard 3 NAMESPACE_LABELS='frequency=weekly'

The last example combines ROUTE_LABELS and NAMESPACE_LABELS to select routes with label sla=low and whose namespace has the label frequency=weekly:

$ modshard 3 \
    NAMESPACE_LABELS='frequency=weekly' \
    ROUTE_LABELS='sla=low'

4.2.11.3. Using Namespace Router Shards

The routes for a project can be handled by a selected router by using NAMESPACE_LABELS. The router is given a selector for a NAMESPACE_LABELS label and the project that wants to use the router applies the NAMESPACE_LABELS label to its namespace.

First, ensure that service account associated with the router has the cluster reader permission. This permits the router to read the labels that are applied to the namespaces.

Now create and label the router:

$ oc adm router ...  --service-account=router
$ oc set env dc/router NAMESPACE_LABELS="router=r1"

Because the router has a selector for a namespace, the router will handle routes for that namespace. So, for example:

$ oc label namespace default "router=r1"

Now create routes in the default namespace, and the route is available in the default router:

$ oc create -f route1.yaml

Now create a new project (namespace) and create a route, route2.

$ oc new-project p1
$ oc create -f route2.yaml

And notice the route is not available in your router. Now label namespace p1 with "router=r1"

$ oc label namespace p1 "router=r1"

Which makes the route available to the router.

Note that removing the label from the namespace won’t have immediate effect (as we don’t see the updates in the router), so if you redeploy/start a new router pod, you should see the unlabelled effects.

$ oc scale dc/router --replicas=0 && oc scale dc/router --replicas=1

4.2.12. Finding the Host Name of the Router

When exposing a service, a user can use the same route from the DNS name that external users use to access the application. The network administrator of the external network must make sure the host name resolves to the name of a router that has admitted the route. The user can set up their DNS with a CNAME that points to this host name. However, the user may not know the host name of the router. When it is not known, the cluster administrator can provide it.

The cluster administrator can use the --router-canonical-hostname option with the router’s canonical host name when creating the router. For example:

# oc adm router myrouter --router-canonical-hostname="rtr.example.com"

This creates the ROUTER_CANONICAL_HOSTNAME environment variable in the router’s deployment configuration containing the host name of the router.

For routers that already exist, the cluster administrator can edit the router’s deployment configuration and add the ROUTER_CANONICAL_HOSTNAME environment variable:

spec:
  template:
    spec:
      containers:
        - env:
          - name: ROUTER_CANONICAL_HOSTNAME
            value: rtr.example.com

The ROUTER_CANONICAL_HOSTNAME value is displayed in the route status for all routers that have admitted the route. The route status is refreshed every time the router is reloaded.

When a user creates a route, all of the active routers evaluate the route and, if conditions are met, admit it. When a router that defines the ROUTER_CANONICAL_HOSTNAME environment variable admits the route, the router places the value in the routerCanonicalHostname field in the route status. The user can examine the route status to determine which, if any, routers have admitted the route, select a router from the list, and find the host name of the router to pass along to the network administrator.

status:
  ingress:
    conditions:
      lastTransitionTime: 2016-12-07T15:20:57Z
      status: "True"
      type: Admitted
      host: hello.in.mycloud.com
      routerCanonicalHostname: rtr.example.com
      routerName: myrouter
      wildcardPolicy: None

oc describe inclues the host name when available:

$ oc describe route/hello-route3
...
Requested Host: hello.in.mycloud.com exposed on router myroute (host rtr.example.com) 12 minutes ago

Using the above information, the user can ask the DNS administrator to set up a CNAME from the route’s host, hello.in.mycloud.com, to the router’s canonical hostname, rtr.example.com. This results in any traffic to hello.in.mycloud.com reaching the user’s application.

4.2.13. Customizing the Default Routing Subdomain

You can customize the suffix used as the default routing subdomain for your environment by modifying the master configuration file (the /etc/origin/master/master-config.yaml file by default). Routes that do not specify a host name would have one generated using this default routing subdomain.

The following example shows how you can set the configured suffix to v3.openshift.test:

routingConfig:
  subdomain: v3.openshift.test
Note

This change requires a restart of the master if it is running.

With the OpenShift Container Platform master(s) running the above configuration, the generated host name for the example of a route named no-route-hostname without a host name added to a namespace mynamespace would be:

no-route-hostname-mynamespace.v3.openshift.test

4.2.14. Forcing Route Host Names to a Custom Routing Subdomain

If an administrator wants to restrict all routes to a specific routing subdomain, they can pass the --force-subdomain option to the oc adm router command. This forces the router to override any host names specified in a route and generate one based on the template provided to the --force-subdomain option.

The following example runs a router, which overrides the route host names using a custom subdomain template ${name}-${namespace}.apps.example.com.

$ oc adm router --force-subdomain='${name}-${namespace}.apps.example.com'

4.2.15. Using Wildcard Certificates

A TLS-enabled route that does not include a certificate uses the router’s default certificate instead. In most cases, this certificate should be provided by a trusted certificate authority, but for convenience you can use the OpenShift Container Platform CA to create the certificate. For example:

$ CA=/etc/origin/master
$ oc adm ca create-server-cert --signer-cert=$CA/ca.crt \
      --signer-key=$CA/ca.key --signer-serial=$CA/ca.serial.txt \
      --hostnames='*.cloudapps.example.com' \
      --cert=cloudapps.crt --key=cloudapps.key
Note

The oc adm ca create-server-cert command generates a certificate that is valid for two years. This can be altered with the --expire-days option, but for security reasons, it is recommended to not make it greater than this value.

The router expects the certificate and key to be in PEM format in a single file:

$ cat cloudapps.crt cloudapps.key $CA/ca.crt > cloudapps.router.pem

From there you can use the --default-cert flag:

$ oc adm router --default-cert=cloudapps.router.pem --service-account=router
Note

Browsers only consider wildcards valid for subdomains one level deep. So in this example, the certificate would be valid for a.cloudapps.example.com but not for a.b.cloudapps.example.com.

4.2.16. Manually Redeploy Certificates

To manually redeploy the router certificates:

  1. Check to see if a secret containing the default router certificate was added to the router:

    $ oc volumes dc/router
    
    deploymentconfigs/router
      secret/router-certs as server-certificate
        mounted at /etc/pki/tls/private

    If the certificate is added, skip the following step and overwrite the secret.

  2. Make sure that you have a default certificate directory set for the following variable DEFAULT_CERTIFICATE_DIR:

    $ oc env dc/router --list
    
    DEFAULT_CERTIFICATE_DIR=/etc/pki/tls/private

    If not, create the directory using the following command:

    $ oc env dc/router DEFAULT_CERTIFICATE_DIR=/etc/pki/tls/private
  3. Export the certificate to PEM format:

    $ cat custom-router.crt custom-ca.crt > custom-router.pem
  4. Overwrite or create a router certificate secret:

    If the certificate secret was added to the router, overwrite the secret. If not, create a new secret.

    To overwrite the secret, run the following command:

    $ oc secrets new router-certs tls.crt=custom-router.crt tls.key=custom-router.key -o json --type='kubernetes.io/tls' --confirm | oc replace -f -

    To create a new secret, run the following commands:

    $ oc secrets new router-certs tls.crt=custom-router.crt tls.key=custom-router.key --type='kubernetes.io/tls' --confirm
    
    $ oc volume dc/router --add --mount-path=/etc/pki/tls/private --secret-name='router-certs' --name router-certs
  5. Deploy the router.

    $ oc rollout latest router

4.2.17. Using Secured Routes

Currently, password protected key files are not supported. HAProxy prompts for a password upon starting and does not have a way to automate this process. To remove a passphrase from a keyfile, you can run:

# openssl rsa -in <passwordProtectedKey.key> -out <new.key>

Here is an example of how to use a secure edge terminated route with TLS termination occurring on the router before traffic is proxied to the destination. The secure edge terminated route specifies the TLS certificate and key information. The TLS certificate is served by the router front end.

First, start up a router instance:

# oc adm router --replicas=1 --service-account=router

Next, create a private key, csr and certificate for our edge secured route. The instructions on how to do that would be specific to your certificate authority and provider. For a simple self-signed certificate for a domain named www.example.test, see the example shown below:

# sudo openssl genrsa -out example-test.key 2048
#
# sudo openssl req -new -key example-test.key -out example-test.csr  \
  -subj "/C=US/ST=CA/L=Mountain View/O=OS3/OU=Eng/CN=www.example.test"
#
# sudo openssl x509 -req -days 366 -in example-test.csr  \
      -signkey example-test.key -out example-test.crt

Generate a route using the above certificate and key.

$ oc create route edge --service=my-service \
    --hostname=www.example.test \
    --key=example-test.key --cert=example-test.crt
route "my-service" created

Look at its definition.

$ oc get route/my-service -o yaml
apiVersion: v1
kind: Route
metadata:
  name:  my-service
spec:
  host: www.example.test
  to:
    kind: Service
    name: my-service
  tls:
    termination: edge
    key: |
      -----BEGIN PRIVATE KEY-----
      [...]
      -----END PRIVATE KEY-----
    certificate: |
      -----BEGIN CERTIFICATE-----
      [...]
      -----END CERTIFICATE-----

Make sure your DNS entry for www.example.test points to your router instance(s) and the route to your domain should be available. The example below uses curl along with a local resolver to simulate the DNS lookup:

# routerip="4.1.1.1"  #  replace with IP address of one of your router instances.
# curl -k --resolve www.example.test:443:$routerip https://www.example.test/

4.2.18. Using Wildcard Routes (for a Subdomain)

The HAProxy router has support for wildcard routes, which are enabled by setting the ROUTER_ALLOW_WILDCARD_ROUTES environment variable to true. Any routes with a wildcard policy of Subdomain that pass the router admission checks will be serviced by the HAProxy router. Then, the HAProxy router exposes the associated service (for the route) per the route’s wildcard policy.

$ oc adm router --replicas=0 ...
$ oc set env dc/router ROUTER_ALLOW_WILDCARD_ROUTES=true
$ oc scale dc/router --replicas=1

Learn how to configure the web console for wildcard routes.

Using a Secure Wildcard Edge Terminated Route

This example reflects TLS termination occurring on the router before traffic is proxied to the destination. Traffic sent to any hosts in the subdomain example.org (*.example.org) is proxied to the exposed service.

The secure edge terminated route specifies the TLS certificate and key information. The TLS certificate is served by the router front end for all hosts that match the subdomain (*.example.org).

  1. Start up a router instance:

    $ oc adm router --replicas=0 --service-account=router
    $ oc set env dc/router ROUTER_ALLOW_WILDCARD_ROUTES=true
    $ oc scale dc/router --replicas=1
  2. Create a private key, certificate signing request (CSR), and certificate for the edge secured route.

    The instructions on how to do this are specific to your certificate authority and provider. For a simple self-signed certificate for a domain named *.example.test, see this example:

    # sudo openssl genrsa -out example-test.key 2048
    #
    # sudo openssl req -new -key example-test.key -out example-test.csr  \
      -subj "/C=US/ST=CA/L=Mountain View/O=OS3/OU=Eng/CN=*.example.test"
    #
    # sudo openssl x509 -req -days 366 -in example-test.csr  \
          -signkey example-test.key -out example-test.crt
  3. Generate a wildcard route using the above certificate and key:

    $ cat > route.yaml  <<REOF
    apiVersion: v1
    kind: Route
    metadata:
      name:  my-service
    spec:
      host: www.example.test
      wildcardPolicy: Subdomain
      to:
        kind: Service
        name: my-service
      tls:
        termination: edge
        key: "$(perl -pe 's/\n/\\n/' example-test.key)"
        certificate: "$(perl -pe 's/\n/\\n/' example-test.cert)"
    REOF
    $ oc create -f route.yaml

    Ensure your DNS entry for *.example.test points to your router instance(s) and the route to your domain is available.

    This example uses curl with a local resolver to simulate the DNS lookup:

    # routerip="4.1.1.1"  #  replace with IP address of one of your router instances.
    # curl -k --resolve www.example.test:443:$routerip https://www.example.test/
    # curl -k --resolve abc.example.test:443:$routerip https://abc.example.test/
    # curl -k --resolve anyname.example.test:443:$routerip https://anyname.example.test/

For routers that allow wildcard routes (ROUTER_ALLOW_WILDCARD_ROUTES set to true), there are some caveats to the ownership of a subdomain associated with a wildcard route.

Prior to wildcard routes, ownership was based on the claims made for a host name with the namespace with the oldest route winning against any other claimants. For example, route r1 in namespace ns1 with a claim for one.example.test would win over another route r2 in namespace ns2 for the same host name one.example.test if route r1 was older than route r2.

In addition, routes in other namespaces were allowed to claim non-overlapping hostnames. For example, route rone in namespace ns1 could claim www.example.test and another route rtwo in namespace d2 could claim c3po.example.test.

This is still the case if there are no wildcard routes claiming that same subdomain (example.test in the above example).

However, a wildcard route needs to claim all of the host names within a subdomain (host names of the form \*.example.test). A wildcard route’s claim is allowed or denied based on whether or not the oldest route for that subdomain (example.test) is in the same namespace as the wildcard route. The oldest route can be either a regular route or a wildcard route.

For example, if there is already a route eldest that exists in the ns1 namespace that claimed a host named owner.example.test and, if at a later point in time, a new wildcard route wildthing requesting for routes in that subdomain (example.test) is added, the claim by the wildcard route will only be allowed if it is the same namespace (ns1) as the owning route.

The following examples illustrate various scenarios in which claims for wildcard routes will succeed or fail.

In the example below, a router that allows wildcard routes will allow non-overlapping claims for hosts in the subdomain example.test as long as a wildcard route has not claimed a subdomain.

$ oc adm router ...
$ oc set env dc/router
$ oc project ns1 ROUTER_ALLOW_WILDCARD_ROUTES=true

$ oc project ns1
$ oc expose service myservice --hostname=owner.example.test
$ oc expose service myservice --hostname=aname.example.test
$ oc expose service myservice --hostname=bname.example.test

$ oc project ns2
$ oc expose service anotherservice --hostname=second.example.test
$ oc expose service anotherservice --hostname=cname.example.test

$ oc project otherns
$ oc expose service thirdservice --hostname=emmy.example.test
$ oc expose service thirdservice --hostname=webby.example.test

In the example below, a router that allows wildcard routes will not allow the claim for owner.example.test or aname.example.test to succeed since the owning namespace is ns1.

$ oc adm router ...
$ oc set env dc/router ROUTER_ALLOW_WILDCARD_ROUTES=true

$ oc project ns1
$ oc expose service myservice --hostname=owner.example.test
$ oc expose service myservice --hostname=aname.example.test

$ oc project ns2
$ oc expose service secondservice --hostname=bname.example.test
$ oc expose service secondservice --hostname=cname.example.test

$ # Router will not allow this claim with a different path name `/p1` as
$ # namespace `ns1` has an older route claiming host `aname.example.test`.
$ oc expose service secondservice --hostname=aname.example.test --path="/p1"

$ # Router will not allow this claim as namespace `ns1` has an older route
$ # claiming host name `owner.example.test`.
$ oc expose service secondservice --hostname=owner.example.test

$ oc project otherns

$ # Router will not allow this claim as namespace `ns1` has an older route
$ # claiming host name `aname.example.test`.
$ oc expose service thirdservice --hostname=aname.example.test

In the example below, a router that allows wildcard routes will allow the claim for `\*.example.test to succeed since the owning namespace is ns1 and the wildcard route belongs to that same namespace.

$ oc adm router ...
$ oc set env dc/router ROUTER_ALLOW_WILDCARD_ROUTES=true

$ oc project ns1
$ oc expose service myservice --hostname=owner.example.test

$ # Reusing the route.yaml from the previous example.
$ # spec:
$ #   host: www.example.test
$ #   wildcardPolicy: Subdomain

$ oc create -f route.yaml   #  router will allow this claim.

In the example below, a router that allows wildcard routes will not allow the claim for `\*.example.test to succeed since the owning namespace is ns1 and the wildcard route belongs to another namespace cyclone.

$ oc adm router ...
$ oc set env dc/router
$ oc project ns1 ROUTER_ALLOW_WILDCARD_ROUTES=true

$ oc project ns1
$ oc expose service myservice --hostname=owner.example.test

$ # Switch to a different namespace/project.
$ oc project cyclone

$ # Reusing the route.yaml from a prior example.
$ # spec:
$ #   host: www.example.test
$ #   wildcardPolicy: Subdomain

$ oc create -f route.yaml   #  router will deny (_NOT_ allow) this claim.

Similarly, once a namespace with a wildcard route claims a subdomain, only routes within that namespace can claim any hosts in that same subdomain.

In the example below, once a route in namespace ns1 with a wildcard route claims subdomain example.test, only routes in the namespace ns1 are allowed to claim any hosts in that same subdomain.

$ oc adm router ...
$ oc set env dc/router
$ oc project ns1 ROUTER_ALLOW_WILDCARD_ROUTES=true

$ oc project ns1
$ oc expose service myservice --hostname=owner.example.test

$ oc project otherns

$ # namespace `otherns` is allowed to claim for other.example.test
$ oc expose service otherservice --hostname=other.example.test

$ oc project ns1

$ # Reusing the route.yaml from the previous example.
$ # spec:
$ #   host: www.example.test
$ #   wildcardPolicy: Subdomain

$ oc create -f route.yaml   #  Router will allow this claim.

$ #  In addition, route in namespace otherns will lose its claim to host
$ #  `other.example.test` due to the wildcard route claiming the subdomain.

$ # namespace `ns1` is allowed to claim for deux.example.test
$ oc expose service mysecondservice --hostname=deux.example.test

$ # namespace `ns1` is allowed to claim for deux.example.test with path /p1
$ oc expose service mythirdservice --hostname=deux.example.test --path="/p1"

$ oc project otherns

$ # namespace `otherns` is not allowed to claim for deux.example.test
$ # with a different path '/otherpath'
$ oc expose service otherservice --hostname=deux.example.test --path="/otherpath"

$ # namespace `otherns` is not allowed to claim for owner.example.test
$ oc expose service yetanotherservice --hostname=owner.example.test

$ # namespace `otherns` is not allowed to claim for unclaimed.example.test
$ oc expose service yetanotherservice --hostname=unclaimed.example.test

In the example below, different scenarios are shown, in which the owner routes are deleted and ownership is passed within and across namespaces. While a route claiming host eldest.example.test in the namespace ns1 exists, wildcard routes in that namespace can claim subdomain example.test. When the route for host eldest.example.test is deleted, the next oldest route senior.example.test would become the oldest route and would not affect any other routes. Once the route for host senior.example.test is deleted, the next oldest route junior.example.test becomes the oldest route and block the wildcard route claimant.

$ oc adm router ...
$ oc set env dc/router
$ oc project ns1 ROUTER_ALLOW_WILDCARD_ROUTES=true

$ oc project ns1
$ oc expose service myservice --hostname=eldest.example.test
$ oc expose service seniorservice --hostname=senior.example.test

$ oc project otherns

$ # namespace `otherns` is allowed to claim for other.example.test
$ oc expose service juniorservice --hostname=junior.example.test

$ oc project ns1

$ # Reusing the route.yaml from the previous example.
$ # spec:
$ #   host: www.example.test
$ #   wildcardPolicy: Subdomain

$ oc create -f route.yaml   #  Router will allow this claim.

$ #  In addition, route in namespace otherns will lose its claim to host
$ #  `junior.example.test` due to the wildcard route claiming the subdomain.

$ # namespace `ns1` is allowed to claim for dos.example.test
$ oc expose service mysecondservice --hostname=dos.example.test

$ # Delete route for host `eldest.example.test`, the next oldest route is
$ # the one claiming `senior.example.test`, so route claims are unaffacted.
$ oc delete route myservice

$ # Delete route for host `senior.example.test`, the next oldest route is
$ # the one claiming `junior.example.test` in another namespace, so claims
$ # for a wildcard route would be affected. The route for the host
$ # `dos.example.test` would be unaffected as there are no other wildcard
$ # claimants blocking it.
$ oc delete route seniorservice

4.2.19. Using the Container Network Stack

The OpenShift Container Platform router runs inside a container and the default behavior is to use the network stack of the host (i.e., the node where the router container runs). This default behavior benefits performance because network traffic from remote clients does not need to take multiple hops through user space to reach the target service and container.

Additionally, this default behavior enables the router to get the actual source IP address of the remote connection rather than getting the node’s IP address. This is useful for defining ingress rules based on the originating IP, supporting sticky sessions, and monitoring traffic, among other uses.

This host network behavior is controlled by the --host-network router command line option, and the default behaviour is the equivalent of using --host-network=true. If you wish to run the router with the container network stack, use the --host-network=false option when creating the router. For example:

$ oc adm router --service-account=router --host-network=false

Internally, this means the router container must publish the 80 and 443 ports in order for the external network to communicate with the router.

Note

Running with the container network stack means that the router sees the source IP address of a connection to be the NATed IP address of the node, rather than the actual remote IP address.

Note

On OpenShift Container Platform clusters using multi-tenant network isolation, routers on a non-default namespace with the --host-network=false option will load all routes in the cluster, but routes across the namespaces will not be reachable due to network isolation. With the --host-network=true option, routes bypass the container network and it can access any pod in the cluster. If isolation is needed in this case, then do not add routes across the namespaces.

4.2.20. Exposing Router Metrics

Using the --metrics-image and --expose-metrics options, you can configure the OpenShift Container Platform router to run a sidecar container that exposes or publishes router metrics for consumption by external metrics collection and aggregation systems (e.g. Prometheus, statsd).

Depending on your router implementation, the image is appropriately set up and the metrics sidecar container is started when the router is deployed. For example, the HAProxy-based router implementation defaults to using the prom/haproxy-exporter image to run as a sidecar container, which can then be used as a metrics datasource by the Prometheus server.

Note

The --metrics-image option overrides the defaults for HAProxy-based router implementations and, in the case of custom implementations, enables the image to use for a custom metrics exporter or publisher.

  1. Grab the HAProxy Prometheus exporter image from the Docker registry:

    $ sudo docker pull prom/haproxy-exporter
  2. Create the OpenShift Container Platform router:

    $ oc adm router --service-account=router --expose-metrics

    Or, optionally, use the --metrics-image option to override the HAProxy defaults:

    $ oc adm router --service-account=router --expose-metrics \
        --metrics-image=prom/haproxy-exporter
  3. Once the haproxy-exporter containers (and your HAProxy router) have started, point Prometheus to the sidecar container on port 9101 on the node where the haproxy-exporter container is running:

    $ haproxy_exporter_ip="<enter-ip-address-or-hostname>"
    $ cat > haproxy-scraper.yml  <<CFGEOF
    ---
    global:
      scrape_interval: "60s"
      scrape_timeout:  "10s"
      # external_labels:
        # source: openshift-router
    
    scrape_configs:
      - job_name:  "haproxy"
        target_groups:
          - targets:
            - "${haproxy_exporter_ip}:9101"
    CFGEOF
    
    $ #  And start prometheus as you would normally using the above config file.
    $ echo "  - Example:  prometheus -config.file=haproxy-scraper.yml "
    $ echo "              or you can start it as a container on {product-title}!!
    
    $ echo "  - Once the prometheus server is up, view the {product-title} HAProxy "
    $ echo "    router metrics at: http://<ip>:9090/consoles/haproxy.html "

4.2.21. Preventing Connection Failures During Restarts

If you connect to the router while the proxy is reloading, there is a small chance that your connection will end up in the wrong network queue and be dropped. The issue is being addressed. In the meantime, it is possible to work around the problem by installing iptables rules to prevent connections during the reload window. However, doing so means that the router needs to run with elevated privilege so that it can manipulate iptables on the host. It also means that connections that happen during the reload are temporarily ignored and must retransmit their connection start, lengthening the time it takes to connect, but preventing connection failure.

To prevent this, configure the router to use iptables by changing the service account, and setting an environment variable on the router.

Use a Privileged SCC

When creating the router, allow it to use the privileged SCC. This gives the router user the ability to create containers with root privileges on the nodes:

$ oc adm policy add-scc-to-user privileged -z router

Patch the Router Deployment Configuration to Create a Privileged Container

You can now create privileged containers. Next, configure the router deployment configuration to use the privilege so that the router can set the iptables rules it needs. This patch changes the router deployment configuration so that the container that is created runs as privileged (and therefore gets correct capabilities) and run as root:

$ oc patch dc router -p '{"spec":{"template":{"spec":{"containers":[{"name":"router","securityContext":{"privileged":true}}],"securityContext":{"runAsUser": 0}}}}}'

Configure the Router to Use iptables

Set the option on the router deployment configuration:

$ oc set env dc/router -c router DROP_SYN_DURING_RESTART=true

If you used a non-default name for the router, you must change dc/router accordingly.

4.2.22. ARP Cache Tuning for Large-scale Clusters

In OpenShift Container Platform clusters with large numbers of routes (greater than the value of net.ipv4.neigh.default.gc_thresh3, which is 65536 by default), you must increase the default values of sysctl variables on each node in the cluster running the router pod to allow more entries in the ARP cache.

When the problem is occuring, the kernel messages would be similar to the following:

[ 1738.811139] net_ratelimit: 1045 callbacks suppressed
[ 1743.823136] net_ratelimit: 293 callbacks suppressed

When this issue occurs, the oc commands might start to fail with the following error:

Unable to connect to the server: dial tcp: lookup <hostname> on <ip>:<port>: write udp <ip>:<port>-><ip>:<port>: write: invalid argument

To verify the actual amount of ARP entries for IPv4, run the following:

# ip -4 neigh show nud all | wc -l

If the number begins to approach the net.ipv4.neigh.default.gc_thresh3 threshold, increase the values. Get the current value by running:

# sysctl net.ipv4.neigh.default.gc_thresh1
net.ipv4.neigh.default.gc_thresh1 = 128
# sysctl net.ipv4.neigh.default.gc_thresh2
net.ipv4.neigh.default.gc_thresh2 = 512
# sysctl net.ipv4.neigh.default.gc_thresh3
net.ipv4.neigh.default.gc_thresh3 = 1024

The following sysctl sets the variables to the OpenShift Container Platform current default values.

# sysctl net.ipv4.neigh.default.gc_thresh1=8192
# sysctl net.ipv4.neigh.default.gc_thresh2=32768
# sysctl net.ipv4.neigh.default.gc_thresh3=65536

To make these settings permanent, see this document.

4.2.23. Protecting Against DDoS Attacks

Add timeout http-request to the default HAProxy router image to protect the deployment against distributed denial-of-service (DDoS) attacks (for example, slowloris):

# and the haproxy stats socket is available at /var/run/haproxy.stats
global
  stats socket ./haproxy.stats level admin

defaults
  option http-server-close
  mode http
  timeout http-request 5s
  timeout connect 5s 1
  timeout server 10s
  timeout client 30s
1
timeout http-request is set up to 5 seconds. HAProxy gives a client 5 seconds *to send its whole HTTP request. Otherwise, HAProxy shuts the connection with *an error.

Also, when the environment variable ROUTER_SLOWLORIS_TIMEOUT is set, it limits the amount of time a client has to send the whole HTTP request. Otherwise, HAProxy will shut down the connection.

Setting the environment variable allows information to be captured as part of the router’s deployment configuration and does not require manual modification of the template, whereas manually adding the HAProxy setting requires you to rebuild the router pod and maintain your router template file.

Using annotations implements basic DDoS protections in the HAProxy template router, including the ability to limit the:

  • number of concurrent TCP connections
  • rate at which a client can request TCP connections
  • rate at which HTTP requests can be made

These are enabled on a per route basis because applications can have extremely different traffic patterns.

Table 4.1. HAProxy Template Router Settings

SettingDescription

haproxy.router.openshift.io/rate-limit-connections

Enables the settings be configured (when set to true, for example).

haproxy.router.openshift.io/rate-limit-connections.concurrent-tcp

The number of concurrent TCP connections that can be made by the same IP address on this route.

haproxy.router.openshift.io/rate-limit-connections.rate-tcp

The number of TCP connections that can be opened by a client IP.

haproxy.router.openshift.io/rate-limit-connections.rate-http

The number of HTTP requests that a client IP can make in a 3-second period.

4.3. Deploying a Customized HAProxy Router

4.3.1. Overview

The default HAProxy router is intended to satisfy the needs of most users. However, it does not expose all of the capability of HAProxy. Therefore, users may need to modify the router for their own needs.

You may need to implement new features within the application back-ends, or modify the current operation. The router plug-in provides all the facilities necessary to make this customization.

The router pod uses a template file to create the needed HAProxy configuration file. The template file is a golang template. When processing the template, the router has access to OpenShift Container Platform information, including the router’s deployment configuration, the set of admitted routes, and some helper functions.

When the router pod starts, and every time it reloads, it creates an HAProxy configuration file, and then it starts HAProxy. The HAProxy configuration manual describes all of the features of HAProxy and how to construct a valid configuration file.

A configMap can be used to add the new template to the router pod. With this approach, the router deployment configuration is modified to mount the configMap as a volume in the router pod. The TEMPLATE_FILE environment variable is set to the full path name of the template file in the router pod.

Alternatively, you can build a custom router image and use it when deploying some or all of your routers. There is no need for all routers to run the same image. To do this, modify the haproxy-template.config file, and rebuild the router image. The new image is pushed to the the cluster’s Docker repository, and the router’s deployment configuration image: field is updated with the new name. When the cluster is updated, the image needs to be rebuilt and pushed.

In either case, the router pod starts with the template file.

4.3.2. Obtaining the Router Configuration Template

The HAProxy template file is fairly large and complex. For some changes, it may be easier to modify the existing template rather than writing a complete replacement. You can obtain a haproxy-config.template file from a running router by running this on master, referencing the router pod:

# oc get po
NAME                       READY     STATUS    RESTARTS   AGE
router-2-40fc3             1/1       Running   0          11d
# oc rsh router-2-40fc3 cat haproxy-config.template > haproxy-config.template
# oc rsh router-2-40fc3 cat haproxy.config > haproxy.config

Alternatively, you can log onto the node that is running the router:

# docker run --rm --interactive=true --tty --entrypoint=cat \
    registry.access.redhat.com/openshift3/ose-haproxy-router:v3.7 haproxy-config.template

The image name is from docker images.

Save this content to a file for use as the basis of your customized template. The saved haproxy.config shows what is actually running.

4.3.3. Modifying the Router Configuration Template

4.3.3.1. Background

The template is based on the golang template. It can reference any of the environment variables in the router’s deployment configuration, any configuration information that is described below, and router provided helper functions.

The structure of the template file mirrors the resulting HAProxy configuration file. As the template is processed, anything not surrounded by {{" something "}} is directly copied to the configuration file. Passages that are surrounded by {{" something "}} are evaluated. The resulting text, if any, is copied to the configuration file.

4.3.3.2. Go Template Actions

The define action names the file that will contain the processed template.

{{define "/var/lib/haproxy/conf/haproxy.config"}}pipeline{{end}}

Table 4.2. Template Router Functions

FunctionMeaning

endpointsForAlias(alias ServiceAliasConfig, svc ServiceUnit) []Endpoint

Returns the list of valid endpoints.

env(variable, default string) string

Tries to get the named environment variable from the pod. Returns the second argument if the variable cannot be read or is empty.

matchPattern(pattern, s string) bool

The first argument is a string that contains the regular expression, the second argument is the variable to test. Returns a Boolean value indicating whether the regular expression provided as the first argument matches the string provided as the second argument.

isInteger(s string) bool

Determines if a given variable is an integer.

matchValues(s string, allowedValues …​string) bool

Compares a given string to a list of allowed strings.

genSubdomainWildcardRegexp(hostname, path string, exactPath bool) string

Generates a regular expression matching the subdomain for hosts (and paths) with a wildcard policy.

generateRouteRegexp(hostname, path string, wildcard bool) string

Generates a regular expression matching the route hosts (and paths). The first argument is the host name, the second is the path, and the third is a wildcard Boolean.

genCertificateHostName(hostname string, wildcard bool) string

Generates host name to use for serving/matching certificates. First argument is the host name and the second is the wildcard Boolean.

These functions are provided by the HAProxy template router plug-in.

4.3.3.3. Router Provided Information

This section reviews the OpenShift Container Platform information that the router makes available to the template. The router configuration parameters are the set of data that the HAProxy router plug-in is given. The fields are accessed by (dot) .Fieldname.

The tables below the Router Configuration Parameters expand on the definitions of the various fields. In particular, .State has the set of admitted routes.

Table 4.3. Router Configuration Parameters

FieldTypeDescription

WorkingDir

string

The directory that files will be written to, defaults to /var/lib/containers/router

State

map[string](ServiceAliasConfig)`

The routes.

ServiceUnits

map[string]ServiceUnit

The service lookup.

DefaultCertificate

string

Full path name to the default certificate in pem format.

PeerEndpoints

`[]Endpoint

Peers.

StatsUser

string

User name to expose stats with (if the template supports it).

StatsPassword

string

Password to expose stats with (if the template supports it).

StatsPort

int

Port to expose stats with (if the template supports it).

BindPorts

bool

Whether the router should bind the default ports.

Table 4.4. Router ServiceAliasConfig (A Route)

FieldTypeDescription

Name

string

The user-specified name of the route.

Namespace

string

The namespace of the route.

Host

string

The host name. For example, www.example.com.

Path

string

Optional path. For example, www.example.com/myservice where myservice is the path.

TLSTermination

routeapi.TLSTerminationType

The termination policy for this back-end; drives the mapping files and router configuration.

Certificates

map[string]Certificate

Certificates used for securing this back-end. Keyed by the certificate ID.

Status

ServiceAliasConfigStatus

Indicates the status of configuration that needs to be persisted.

PreferPort

string

Indicates the port the user wants to expose. If empty, a port will be selected for the service.

InsecureEdgeTerminationPolicy

routeapi.InsecureEdgeTerminationPolicyType

Indicates desired behavior for insecure connections to an edge-terminated route: none (or disable), allow, or redirect.

RoutingKeyName

string

Hash of the route + namespace name used to obscure the cookie ID.

IsWildcard

bool

Indicates this service unit needing wildcard support.

Annotations

map[string]string

Annotations attached to this route.

ServiceUnitNames

map[string]int32

Collection of services that support this route, keyed by service name and valued on the weight attached to it with respect to other entries in the map.

ActiveServiceUnits

int

Count of the ServiceUnitNames with a non-zero weight.

The ServiceAliasConfig is a route for a service. Uniquely identified by host + path. The default template iterates over routes using {{range $cfgIdx, $cfg := .State }}. Within such a {{range}} block, the template can refer to any field of the current ServiceAliasConfig using $cfg.Field.

Table 4.5. Router ServiceUnit

FieldTypeDescription

Name

string

Name corresponds to a service name + namespace. Uniquely identifies the ServiceUnit.

EndpointTable

[]Endpoint

Endpoints that back the service. This translates into a final back-end implementation for routers.

ServiceUnit is an encapsulation of a service, the endpoints that back that service, and the routes that point to the service. This is the data that drives the creation of the router configuration files

Table 4.6. Router Endpoint

FieldType

ID

string

IP

string

Port

string

TargetName

string

PortName

string

IdHash

string

NoHealthCheck

bool

Endpoint is an internal representation of a Kubernetes endpoint.

Table 4.7. Router Certificate, ServiceAliasConfigStatus

FieldTypeDescription

Certificate

string

Represents a public/private key pair. It is identified by an ID, which will become the file name. A CA certificate will not have a PrivateKey set.

ServiceAliasConfigStatus

string

Indicates that the necessary files for this configuration have been persisted to disk. Valid values: "saved", "".

Table 4.8. Router Certificate Type

FieldTypeDescription

ID

string

 

Contents

string

The certificate.

PrivateKey

string

The private key.

Table 4.9. Router TLSTerminationType

FieldTypeDescription

TLSTerminationType

string

Dictates where the secure communication will stop.

InsecureEdgeTerminationPolicyType

string

Indicates the desired behavior for insecure connections to a route. While each router may make its own decisions on which ports to expose, this is normally port 80.

TLSTerminationType and InsecureEdgeTerminationPolicyType dictate where the secure communication will stop.

Table 4.10. Router TLSTerminationType Values

ConstantValueMeaning

TLSTerminationEdge

edge

Terminate encryption at the edge router.

TLSTerminationPassthrough

passthrough

Terminate encryption at the destination, the destination is responsible for decrypting traffic.

TLSTerminationReencrypt

reencrypt

Terminate encryption at the edge router and re-encrypt it with a new certificate supplied by the destination.

Table 4.11. Router InsecureEdgeTerminationPolicyType Values

TypeMeaning

Allow

Traffic is sent to the server on the insecure port (default).

Disable

No traffic is allowed on the insecure port.

Redirect

Clients are redirected to the secure port.

None ("") is the same as Disable.

4.3.3.4. Annotations

Each route can have annotations attached. Each annotation is just a name and a value.

apiVersion: v1
kind: Route
metadata:
  annotations:
    haproxy.router.openshift.io/timeout: 5500ms
[...]

The name can be anything that does not conflict with existing Annotations. The value is any string. The string can have multiple tokens separated by a space. For example, aa bb cc. The template uses {{index}} to extract the value of an annotation. For example:

{{$balanceAlgo := index $cfg.Annotations "haproxy.router.openshift.io/balance"}}

This is an example of how this could be used for mutual client authorization.

{{ with $cnList := index $cfg.Annotations "whiteListCertCommonName" }}
  {{   if ne $cnList "" }}
    acl test ssl_c_s_dn(CN) -m str {{ $cnList }}
    http-request deny if !test
  {{   end }}
{{ end }}

Then, you can handle the white-listed CNs with this command.

$ oc annotate route <route-name> --overwrite whiteListCertCommonName="CN1 CN2 CN3"

See Route-specific Annotations for more information.

4.3.3.5. Environment Variables

The template can use any environment variables that exist in the router pod. The environment variables can be set in the deployment configuration. New environment variables can be added.

They are referenced by the env function:

{{env "ROUTER_MAX_CONNECTIONS" "20000"}}

The first string is the variable, and the second string is the default when the variable is missing or nil. When ROUTER_MAX_CONNECTIONS is not set or is nil, 20000 is used. Environment variables are a map where the key is the environment variable name and the content is the value of the variable.

See Route-specific Environment variables for more information.

4.3.3.6. Example Usage

Here is a simple template based on the HAProxy template file.

Start with a comment:

{{/*
  Here is a small example of how to work with templates
  taken from the HAProxy template file.
*/}}

The template can create any number of output files. Use a define construct to create an output file. The file name is specified as an argument to define, and everything inside the define block up to the matching end is written as the contents of that file.

{{ define "/var/lib/haproxy/conf/haproxy.config" }}
global
{{ end }}

The above will copy global to the /var/lib/haproxy/conf/haproxy.config file, and then close the file.

Set up logging based on environment variables.

{{ with (env "ROUTER_SYSLOG_ADDRESS" "") }}
  log {{.}} {{env "ROUTER_LOG_FACILITY" "local1"}} {{env "ROUTER_LOG_LEVEL" "warning"}}
{{ end }}

The env function extracts the value for the environment variable. If the environment variable is not defined or nil, the second argument is returned.

The with construct sets the value of "." (dot) within the with block to whatever value is provided as an argument to with. The with action tests Dot for nil. If not nil, the clause is processed up to the end. In the above, assume ROUTER_SYSLOG_ADDRESS contains /var/log/msg, ROUTER_LOG_FACILITY is not defined, and ROUTER_LOG_LEVEL contains info. The following will be copied to the output file:

  log /var/log/msg local1 info

Each admitted route ends up generating lines in the configuration file. Use range to go through the admitted routes:

{{ range $cfgIdx, $cfg := .State }}
  backend be_http_{{$cfgIdx}}
{{end}}

.State is a map of ServiceAliasConfig, where the key is the route name. range steps through the map and, for each pass, it sets $cfgIdx with the key, and sets `$cfg to point to the ServiceAliasConfig that describes the route. If there are two routes named myroute and hisroute, the above will copy the following to the output file:

  backend be_http_myroute
  backend be_http_hisroute

Route Annotations, $cfg.Annotations, is also a map with the annotation name as the key and the content string as the value. The route can have as many annotations as desired and the use is defined by the template author. The user codes the annotation into the route and the template author customized the HAProxy template to handle the annotation.

The common usage is to index the annotation to get the value.

{{$balanceAlgo := index $cfg.Annotations "haproxy.router.openshift.io/balance"}}

The index extracts the value for the given annotation, if any. Therefore, `$balanceAlgo will contain the string associated with the annotation or nil. As above, you can test for a non-nil string and act on it with the with construct.

{{ with $balanceAlgo }}
  balance $balanceAlgo
{{ end }}

Here when $balanceAlgo is not nil, balance $balanceAlgo is copied to the output file.

In a second example, you want to set a server timeout based on a timeout value set in an annotation.

$value := index $cfg.Annotations "haproxy.router.openshift.io/timeout"

The $value can now be evaluated to make sure it contains a properly constructed string. The matchPattern function accepts a regular expression and returns true if the argument satisfies the expression.

matchPattern "[1-9][0-9]*(us\|ms\|s\|m\|h\|d)?" $value

This would accept 5000ms but not 7y. The results can be used in a test.

{{if (matchPattern "[1-9][0-9]*(us\|ms\|s\|m\|h\|d)?" $value) }}
  timeout server  {{$value}}
{{ end }}

It can also be used to match tokens:

matchPattern "roundrobin|leastconn|source" $balanceAlgo

Alternatively matchValues can be used to match tokens:

matchValues $balanceAlgo "roundrobin" "leastconn" "source"

4.3.4. Using a ConfigMap to Replace the Router Configuration Template

You can use a ConfigMap to customize the router instance without rebuilding the router image. The haproxy-config.template, reload-haproxy, and other scripts can be modified as well as creating and modifying router environment variables.

  1. Copy the haproxy-config.template that you want to modify as described above. Modify it as desired.
  2. Create a ConfigMap:

    $ oc create configmap customrouter --from-file=haproxy-config.template

    The customrouter ConfigMap now contains a copy of the modified haproxy-config.template file.

  3. Modify the router deployment configuration to mount the ConfigMap as a file and point the TEMPLATE_FILE environment variable to it. This can be done via oc set env and oc volume commands, or alternatively by editing the router deployment configuration.

    Using oc commands
    $ oc volume dc/router --add --overwrite \
        --name=config-volume \
        --mount-path=/var/lib/haproxy/conf/custom \
        --source='{"configMap": { "name": "customrouter"}}'
    $ oc set env dc/router \
        TEMPLATE_FILE=/var/lib/haproxy/conf/custom/haproxy-config.template
    Editing the Router Deployment Configuration

    Use oc edit dc router to edit the router deployment configuration with a text editor.

    ...
            - name: STATS_USERNAME
              value: admin
            - name: TEMPLATE_FILE  1
              value: /var/lib/haproxy/conf/custom/haproxy-config.template
            image: openshift/origin-haproxy-routerp
    ...
            terminationMessagePath: /dev/termination-log
            volumeMounts: 2
            - mountPath: /var/lib/haproxy/conf/custom
              name: config-volume
          dnsPolicy: ClusterFirst
    ...
          terminationGracePeriodSeconds: 30
          volumes: 3
          - configMap:
              name: customrouter
            name: config-volume
      test: false
    ...
    1
    In the spec.container.env field, add the TEMPLATE_FILE environment variable to point to the mounted haproxy-config.template file.
    2
    Add the spec.container.volumeMounts field to create the mount point.
    3
    Add a new spec.volumes field to mention the ConfigMap.

    Save the changes and exit the editor. This restarts the router.

4.3.5. Using Stick Tables

The following example customization can be used in a highly-available routing setup to use stick-tables that synchronize between peers.

Adding a Peer Section

In order to synchronize stick-tables amongst peers you must a define a peers section in your HAProxy configuration. This section determines how HAProxy will identify and connect to peers. The plug-in provides data to the template under the .PeerEndpoints variable to allow you to easily identify members of the router service. You may add a peer section to the haproxy-config.template file inside the router image by adding:

{{ if (len .PeerEndpoints) gt 0 }}
peers openshift_peers
  {{ range $endpointID, $endpoint := .PeerEndpoints }}
    peer {{$endpoint.TargetName}} {{$endpoint.IP}}:1937
  {{ end }}
{{ end }}

Changing the Reload Script

When using stick-tables, you have the option of telling HAProxy what it should consider the name of the local host in the peer section. When creating endpoints, the plug-in attempts to set the TargetName to the value of the endpoint’s TargetRef.Name. If TargetRef is not set, it will set the TargetName to the IP address. The TargetRef.Name corresponds with the Kubernetes host name, therefore you can add the -L option to the reload-haproxy script to identify the local host in the peer section.

peer_name=$HOSTNAME 1

if [ -n "$old_pid" ]; then
  /usr/sbin/haproxy -f $config_file -p $pid_file -L $peer_name -sf $old_pid
else
  /usr/sbin/haproxy -f $config_file -p $pid_file -L $peer_name
fi
1
Must match an endpoint target name that is used in the peer section.

Modifying Back Ends

Finally, to use the stick-tables within back ends, you can modify the HAProxy configuration to use the stick-tables and peer set. The following is an example of changing the existing back end for TCP connections to use stick-tables:

            {{ if eq $cfg.TLSTermination "passthrough" }}
backend be_tcp_{{$cfgIdx}}
  balance leastconn
  timeout check 5000ms
  stick-table type ip size 1m expire 5m{{ if (len $.PeerEndpoints) gt 0 }} peers openshift_peers {{ end }}
  stick on src
                {{ range $endpointID, $endpoint := $serviceUnit.EndpointTable }}
  server {{$endpointID}} {{$endpoint.IP}}:{{$endpoint.Port}} check inter 5000ms
                {{ end }}
            {{ end }}

After this modification, you can rebuild your router.

4.3.6. Rebuilding Your Router

In order to rebuild the router, you need copies of several files that are present on a running router. Make a work directory and copy the files from the router:

# mkdir - myrouter/conf
# cd myrouter
# oc get po
NAME                       READY     STATUS    RESTARTS   AGE
router-2-40fc3             1/1       Running   0          11d
# oc rsh router-2-40fc3 cat haproxy-config.template > conf/haproxy-config.template
# oc rsh router-2-40fc3 cat error-page-503.http > conf/error-page-503.http
# oc rsh router-2-40fc3 cat default_pub_keys.pem > conf/default_pub_keys.pem
# oc rsh router-2-40fc3 cat ../Dockerfile > Dockerfile
# oc rsh router-2-40fc3 cat ../reload-haproxy > reload-haproxy

You can edit or replace any of these files. However, conf/haproxy-config.template and reload-haproxy are the most likely to be modified.

After updating the files:

# docker build -t openshift/origin-haproxy-router-myversion .
# docker tag openshift/origin-haproxy-router-myversion 172.30.243.98:5000/openshift/haproxy-router-myversion 1
# docker push 172.30.243.98:5000/openshift/origin-haproxy-router-pc:latest 2
1
Tag the version with the repository. In this case the repository is 172.30.243.98:5000.
2
Push the tagged version to the repository. It may be necessary to docker login to the repository first.

To use the new router, edit the router deployment configuration either by changing the image: string or by adding the --images=<repo>/<image>:<tag> flag to the oadm router command.

When debugging the changes, it is helpful to set imagePullPolicy: Always in the deployment configuration to force an image pull on each pod creation. When debugging is complete, you can change it back to imagePullPolicy: IfNotPresent to avoid the pull on each pod start.

4.4. Configuring the HAProxy Router to Use the PROXY Protocol

4.4.1. Overview

By default, the HAProxy router expects incoming connections to unsecure, edge, and re-encrypt routes to use HTTP. However, you can configure the router to expect incoming requests by using the PROXY protocol instead. This topic describes how to configure the HAProxy router and an external load balancer to use the PROXY protocol.

4.4.2. Why Use the PROXY Protocol?

When an intermediary service such as a proxy server or load balancer forwards an HTTP request, it appends the source address of the connection to the request’s "Forwarded" header in order to provide this information to subsequent intermediaries and to the back-end service to which the request is ultimately forwarded. However, if the connection is encrypted, intermediaries cannot modify the "Forwarded" header. In this case, the HTTP header will not accurately communicate the original source address when the request is forwarded.

To solve this problem, some load balancers encapsulate HTTP requests using the PROXY protocol as an alternative to simply forwarding HTTP. Encapsulation enables the load balancer to add information to the request without modifying the forwarded request itself. In particular, this means that the load balancer can communicate the source address even when forwarding an encrypted connection.

The HAProxy router can be configured to accept the PROXY protocol and decapsulate the HTTP request. Because the router terminates encryption for edge and re-encrypt routes, the router can then update the "Forwarded" HTTP header (and related HTTP headers) in the request, appending any source address that is communicated using the PROXY protocol.

Warning

The PROXY protocol and HTTP are incompatible and cannot be mixed. If you use a load balancer in front of the router, both must use either the PROXY protocol or HTTP. Configuring one to use one protocol and the other to use the other protocol will cause routing to fail.

4.4.3. Using the PROXY Protocol

By default, the HAProxy router does not use the PROXY protocol. The router can be configured using the ROUTER_USE_PROXY_PROTOCOL environment variable to expect the PROXY protocol for incoming connections:

Enable the PROXY Protocol

$ oc env dc/router ROUTER_USE_PROXY_PROTOCOL=true

Set the variable to any value other than true or TRUE to disable the PROXY protocol:

Disable the PROXY Protocol

$ oc env dc/router ROUTER_USE_PROXY_PROTOCOL=false

If you enable the PROXY protocol in the router, you must configure your load balancer in front of the router to use the PROXY protocol as well. Following is an example of configuring Amazon’s Elastic Load Balancer (ELB) service to use the PROXY protocol. This example assumes that ELB is forwarding ports 80 (HTTP), 443 (HTTPS), and 5000 (for the image registry) to the router running on one or more EC2 instances.

Configure Amazon ELB to Use the PROXY Protocol

  1. To simplify subsequent steps, first set some shell variables:

    $ lb='infra-lb' 1
    $ instances=( 'i-079b4096c654f563c' ) 2
    $ secgroups=( 'sg-e1760186' ) 3
    $ subnets=( 'subnet-cf57c596' ) 4
    1
    The name of your ELB.
    2
    The instance or instances on which the router is running.
    3
    The security group or groups for this ELB.
    4
    The subnet or subnets for this ELB.
  2. Next, create the ELB with the appropriate listeners, security groups, and subnets.

    Note

    You must configure all listeners to use the TCP protocol, not the HTTP protocol.

    $ aws elb create-load-balancer --load-balancer-name "$lb" \
       --listeners \
        'Protocol=TCP,LoadBalancerPort=80,InstanceProtocol=TCP,InstancePort=80' \
        'Protocol=TCP,LoadBalancerPort=443,InstanceProtocol=TCP,InstancePort=443' \
        'Protocol=TCP,LoadBalancerPort=5000,InstanceProtocol=TCP,InstancePort=5000' \
       --security-groups $secgroups \
       --subnets $subnets
    {
        "DNSName": "infra-lb-2006263232.us-east-1.elb.amazonaws.com"
    }
  3. Register your router instance or instances with the ELB:

    $ aws elb register-instances-with-load-balancer --load-balancer-name "$lb" \
       --instances $instances
    {
        "Instances": [
            {
                "InstanceId": "i-079b4096c654f563c"
            }
        ]
    }
  4. Configure the ELB’s health check:

    $ aws elb configure-health-check --load-balancer-name "$lb" \
       --health-check 'Target=HTTP:1936/healthz,Interval=30,UnhealthyThreshold=2,HealthyThreshold=2,Timeout=5'
    {
        "HealthCheck": {
            "HealthyThreshold": 2,
            "Interval": 30,
            "Target": "HTTP:1936/healthz",
            "Timeout": 5,
            "UnhealthyThreshold": 2
        }
    }
  5. Finally, create a load-balancer policy with the ProxyProtocol attribute enabled, and configure it on the ELB’s TCP ports 80 and 443:

    $ aws elb create-load-balancer-policy --load-balancer-name "$lb" \
       --policy-name "${lb}-ProxyProtocol-policy" \
       --policy-type-name 'ProxyProtocolPolicyType' \
       --policy-attributes 'AttributeName=ProxyProtocol,AttributeValue=true'
    $ for port in 80 443
      do
        aws elb set-load-balancer-policies-for-backend-server \
         --load-balancer-name "$lb" \
         --instance-port "$port" \
         --policy-names "${lb}-ProxyProtocol-policy"
      done

Verify the Configuration

You can examine the load balancer as follows to verify that the configuration is correct:

$ aws elb describe-load-balancers --load-balancer-name "$lb" |
    jq '.LoadBalancerDescriptions| [.[]|.ListenerDescriptions]'
[
  [
    {
      "Listener": {
        "InstancePort": 80,
        "LoadBalancerPort": 80,
        "Protocol": "TCP",
        "InstanceProtocol": "TCP"
      },
      "PolicyNames": ["infra-lb-ProxyProtocol-policy"] 1
    },
    {
      "Listener": {
        "InstancePort": 443,
        "LoadBalancerPort": 443,
        "Protocol": "TCP",
        "InstanceProtocol": "TCP"
      },
      "PolicyNames": ["infra-lb-ProxyProtocol-policy"] 2
    },
    {
      "Listener": {
        "InstancePort": 5000,
        "LoadBalancerPort": 5000,
        "Protocol": "TCP",
        "InstanceProtocol": "TCP"
      },
      "PolicyNames": [] 3
    }
  ]
]
1
The listener for TCP port 80 should have the policy for using the PROXY protocol.
2
The listener for TCP port 443 should have the same policy.
3
The listener for TCP port 5000 should not have the policy.

Alternatively, if you already have an ELB configured, but it is not configured to use the PROXY protocol, you will need to change the existing listener for TCP port 80 to use the TCP protocol instead of HTTP (TCP port 443 should already be using the TCP protocol):

$ aws elb delete-load-balancer-listeners --load-balancer-name "$lb" \
   --load-balancer-ports 80
$ aws elb create-load-balancer-listeners --load-balancer-name "$lb" \
   --listeners 'Protocol=TCP,LoadBalancerPort=80,InstanceProtocol=TCP,InstancePort=80'

Verify the Protocol Updates

Verify that the protocol has been updated as follows:

$ aws elb describe-load-balancers --load-balancer-name "$lb" |
   jq '[.LoadBalancerDescriptions[]|.ListenerDescriptions]'
[
  [
    {
      "Listener": {
        "InstancePort": 443,
        "LoadBalancerPort": 443,
        "Protocol": "TCP",
        "InstanceProtocol": "TCP"
      },
      "PolicyNames": []
    },
    {
      "Listener": {
        "InstancePort": 5000,
        "LoadBalancerPort": 5000,
        "Protocol": "TCP",
        "InstanceProtocol": "TCP"
      },
      "PolicyNames": []
    },
    {
      "Listener": {
        "InstancePort": 80,
        "LoadBalancerPort": 80,
        "Protocol": "TCP", 1
        "InstanceProtocol": "TCP"
      },
      "PolicyNames": []
    }
  ]
]
1
All listeners, including the listener for TCP port 80, should be using the TCP protocol.

Then, create a load-balancer policy and add it to the ELB as described in Step 5 above.

4.5. Using the F5 Router Plug-in

4.5.1. Overview

Note

The F5 router plug-in is available starting in OpenShift Container Platform 3.0.2.

The F5 router plug-in is provided as a container image and run as a pod, just like the default HAProxy router.

Important

Support relationships between F5 and Red Hat provide a full scope of support for F5 integration. F5 provides support for the F5 BIG-IP® product. Both F5 and Red Hat jointly support the integration with Red Hat OpenShift. While Red Hat helps with bug fixes and feature enhancements, all get communicated to F5 Networks where they are managed as part of their development cycles.

4.5.2. Prerequisites and Supportability

When deploying the F5 router plug-in, ensure you meet the following requirements:

  • A F5 host IP with:

    • Credentials for API access
    • SSH access via a private key
  • A virtual server for HTTP routes:

    • HTTP profile must be http.
  • A virtual server with HTTP profile routes:

    • HTTP profile must be http
    • SSL Profile (client) must be clientssl
    • SSL Profile (server) must be serverssl
  • For edge integration (not recommended):

    • A working ramp node
    • A working tunnel to the ramp node
  • For native integration:

    • A host-internal IP capable of communicating with all nodes on the port 4789/UDP
    • The sdn-services add-on license installed on the F5 host.

OpenShift Container Platform supports only the following F5 BIG-IP® versions:

  • 11.x
  • 12.x
Important

The following features are not supported with F5 BIG-IP®:

  • Wildcard routes together with re-encrypt routes - you must supply a certificate and a key in the route. If you provide a certificate, a key, and a certificate authority (CA), the CA is never used.
  • A pool is created for all services, even for the ones with no associated route.
  • Idling applications
  • Unencrypted HTTP traffic in allow and redirect mode, with edge TLS termination. (insecureEdgeTerminationPolicy (Allow/Redirect))
  • Sharding, that is, having multiple vservers on the F5.
  • SSL cipher (ROUTER_CIPHERS=modern/old)

4.5.2.1. Configuring the Virtual Servers

As a prerequisite to working with the openshift-F5 integrated router, two virtual servers (one virtual server each for HTTP and HTTPS profiles, respectively) need to be set up in the F5 BIG-IP® appliance.

To set up a virtual server in the F5 BIG-IP® appliance, follow the instructions from F5.

While creating the virtual server, ensure the following settings are in place:

  • For the HTTP server, set the ServicePort to 'http'/80.
  • For the HTTPS server, set the ServicePort to 'https'/443.
  • In the basic configuration, set the HTTP profile to /Common/http for both of the virtual servers.
  • For the HTTPS server, create a default client-ssl profile and select it for the SSL Profile (Client).

    • To create the default client SSL profile, follow the instructions from F5, especially the Configuring the fallback (default) client SSL profile section, which discusses that the certificate/key pair is the default that will be served in the case that custom certificates are not provided for a route or server name.

4.5.3. Deploying the F5 Router

Important

The F5 router must be run in privileged mode, because route certificates are copied using the scp command:

$ oc adm policy remove-scc-from-user hostnetwork -z router
$ oc adm policy add-scc-to-user privileged -z router

Deploy the F5 router with the oadm router command, but provide additional flags (or environment variables) specifying the following parameters for the F5 BIG-IP® host:

FlagDescription

--type=f5-router

Specifies that an F5 router should be launched (the default --type is haproxy-router).

--external-host

Specifies the F5 BIG-IP® host’s management interface’s host name or IP address.

--external-host-username

Specifies the F5 BIG-IP® user name (typically admin).

--external-host-password

Specifies the F5 BIG-IP® password.

--external-host-http-vserver

Specifies the name of the F5 virtual server for HTTP connections. This must be configured by the user prior to launching the router pod.

--external-host-https-vserver

Specifies the name of the F5 virtual server for HTTPS connections. This must be configured by the user prior to launching the router pod.

--external-host-private-key

Specifies the path to the SSH private key file for the F5 BIG-IP® host. Required to upload and delete key and certificate files for routes.

--external-host-insecure

A Boolean flag that indicates that the F5 router should skip strict certificate verification with the F5 BIG-IP® host.

--external-host-partition-path

Specifies the F5 BIG-IP® partition path (the default is /Common).

For example:

$ oadm router \
    --type=f5-router \
    --external-host=10.0.0.2 \
    --external-host-username=admin \
    --external-host-password=mypassword \
    --external-host-http-vserver=ose-vserver \
    --external-host-https-vserver=https-ose-vserver \
    --external-host-private-key=/path/to/key \
    --host-network=false \
    --service-account=router

As with the HAProxy router, the oadm router command creates the service and deployment configuration objects, and thus the replication controllers and pod(s) in which the F5 router itself runs. The replication controller restarts the F5 router in case of crashes. Because the F5 router is watching routes, endpoints, and nodes and configuring F5 BIG-IP® accordingly, running the F5 router in this way, along with an appropriately configured F5 BIG-IP® deployment, should satisfy high-availability requirements.

4.5.4. F5 Router Partition Paths

Partition paths allow you to store your OpenShift Container Platform routing configuration in a custom F5 BIG-IP® administrative partition, instead of the default /Common partition. You can use custom administrative partitions to secure F5 BIG-IP® environments. This means that an OpenShift Container Platform-specific configuration stored in F5 BIG-IP® system objects reside within a logical container, allowing administrators to define access control policies on that specific administrative partition.

See the F5 BIG-IP® documentation for more information about administrative partitions.

To configure your OpenShift Container Platform for partition paths:

  1. Optionally, perform some cleaning steps:

    1. Ensure F5 is configured to be able to switch to the /Common and /Custom paths.
    2. Delete the static FDB of vxlan5000. See the F5 BIG-IP® documentation for more information.
  2. Configure a virtual server for the custom partition.
  3. Deploy the F5 router using the --external-host-partition-path flag to specify a partition path:

    $ oadm router --external-host-partition-path=/OpenShift/zone1 ...

4.5.5. Setting Up F5 Native Integration

Note

This section reviews how to set up F5 native integration with OpenShift Container Platform. The concepts of F5 appliance and OpenShift Container Platform connection and data flow of F5 native integration are discussed in the F5 Native Integration section.

Note

Only F5 BIG-IP® appliance version 12.x and above works with the native integration presented in this section. You also need sdn-services add-on license for the integration to work properly. For version 11.x, follow the instructions to set up a ramp node.

As of OpenShift Container Platform version 3.4, using native integration of F5 with OpenShift Container Platform does not require configuring a ramp node for F5 to be able to reach the pods on the overlay network as created by OpenShift SDN.

The F5 controller pod needs to be launched with enough information so that it can successfully directly connect to pods.

  1. Create a ghost hostsubnet on the OpenShift Container Platform cluster:

    $ cat > f5-hostsubnet.yaml << EOF
    {
        "kind": "HostSubnet",
        "apiVersion": "v1",
        "metadata": {
            "name": "openshift-f5-node",
            "annotations": {
            "pod.network.openshift.io/assign-subnet": "true",
    	"pod.network.openshift.io/fixed-vnid-host": "0"  1
            }
        },
        "host": "openshift-f5-node",
        "hostIP": "10.3.89.213"  2
    } EOF
    $ oc create -f f5-hostsubnet.yaml
    1
    Make F5 global.
    2
    The internal IP of the F5 appliance.
  2. Determine the subnet allocated for the ghost hostsubnet just created:

    $ oc get hostsubnets
    NAME                    HOST                    HOST IP       SUBNET
    openshift-f5-node       openshift-f5-node       10.3.89.213   10.131.0.0/23
    openshift-master-node   openshift-master-node   172.17.0.2    10.129.0.0/23
    openshift-node-1        openshift-node-1        172.17.0.3    10.128.0.0/23
    openshift-node-2        openshift-node-2        172.17.0.4    10.130.0.0/23
  3. Check the SUBNET for the newly created hostsubnet. In this example, 10.131.0.0/23.
  4. Get the entire pod network’s CIDR:

    $ oc get clusternetwork

    This value will be something like 10.128.0.0/14, noting the mask (14 in this example).

  5. To construct the gateway address, pick any IP address from the hostsubnet (for example, 10.131.0.5). Use the mask of the pod network (14). The gateway address becomes: 10.131.0.5/14.
  6. Launch the F5 controller pod, following these instructions. Additionally, allow the access to 'node' cluster resource for the service account and use the two new additional options for VXLAN native integration.

    $ # Add policy to allow router to access nodes using the sdn-reader role
    $ oadm policy add-cluster-role-to-user system:sdn-reader system:serviceaccount:default:router
    $ # Launch the router pod with vxlan-gw and F5's internal IP as extra arguments
    $ #--external-host-internal-ip=10.3.89.213
    $ #--external-host-vxlan-gw=10.131.0.5/14
    $ oadm router \
        --type=f5-router \
        --external-host=10.3.89.90 \
        --external-host-username=admin \
        --external-host-password=mypassword \
        --external-host-http-vserver=ose-vserver \
        --external-host-https-vserver=https-ose-vserver \
        --external-host-private-key=/path/to/key \
        --service-account=router \
        --host-network=false \
        --external-host-internal-ip=10.3.89.213 \
        --external-host-vxlan-gw=10.131.0.5/14

    The F5 setup is now ready, without the need to set up the ramp node.

Chapter 5. Upgrading a Cluster

5.1. Overview

When new versions of OpenShift Container Platform are released, you can upgrade your existing cluster to apply the latest enhancements and bug fixes. This includes upgrading from previous minor versions, such as release 3.6 to 3.7, and applying asynchronous errata updates within a minor version (3.7.z releases). See the OpenShift Container Platform 3.7 Release Notes to review the latest changes.

Note

Due to the core architectural changes between the major versions, OpenShift Enterprise 2 environments cannot be upgraded to OpenShift Container Platform 3 and require a fresh installation.

Unless noted otherwise, node and masters within a major version are forward and backward compatible across one minor version, so upgrading your cluster should go smoothly. However, you should not run mismatched versions longer than necessary to upgrade the entire cluster.

5.1.1. In-place or Blue-Green Upgrades

There are two methods for performing OpenShift Container Platform cluster upgrades. You can either do in-place upgrades (automated or manual), or upgrade using a blue-green deployment method.

In-place Upgrades

With in-place upgrades, the cluster upgrade is performed on all hosts in a single, running cluster: first masters and then nodes. Pods are evacuated off of nodes and recreated on other running nodes before a node upgrade begins; this helps reduce downtime of user applications.

If you installed using the quick or advanced installation and the ~/.config/openshift/installer.cfg.yml or inventory file that was used is available, you can perform an automated in-place upgrade. Alternatively, you can upgrade in-place manually.

Blue-green Deployments

The blue-green deployment upgrade method follows a similar flow to the in-place method: masters and etcd servers are still upgraded first, however a parallel environment is created for new nodes instead of upgrading them in-place.

This method allows administrators to switch traffic from the old set of nodes (e.g., the "blue" deployment) to the new set (e.g., the "green" deployment) after the new deployment has been verified. If a problem is detected, it is also then easy to rollback to the old deployment quickly.

5.2. Performing Automated In-place Cluster Upgrades

5.2.1. Overview

If you installed using the advanced installation and the inventory file that was used is available, you can use the upgrade playbook to automate the OpenShift cluster upgrade process. If you installed using the quick installation method and a ~/.config/openshift/installer.cfg.yml file is available, you can use the quick installer to perform the automated upgrade.

The automated upgrade performs the following steps for you:

  • Applies the latest configuration.
  • Upgrades master and etcd components and restarts services.
  • Upgrades node components and restarts services.
  • Applies the latest cluster policies.
  • Updates the default router if one exists.
  • Updates the default registry if one exists.
  • Updates default image streams and InstantApp templates.
Important

Ensure that you have met all prerequisites before proceeding with an upgrade. Failure to do so can result in a failed upgrade.

5.2.2. Preparing for an Automated Upgrade

Important

Before upgrading your cluster to OpenShift Container Platform 3.7, the cluster must be already upgraded to the latest asynchronous release of version 3.6. Cluster upgrades cannot span more than one minor version at a time, so if your cluster is at a version earlier than 3.6, you must first upgrade incrementally (e.g., 3.4 to 3.5, then 3.5 to 3.6).

Note

Before attempting the upgrade, follow the steps in Verifying the Upgrade to verify the cluster’s health. This will confirm that nodes are in the Ready state, running the expected starting version, and will ensure that there are no diagnostic errors or warnings.

To prepare for an automated upgrade:

  1. Pull the latest subscription data from RHSM:

    # subscription-manager refresh
  2. If you are upgrading from OpenShift Container Platform 3.6 to 3.7, manually disable the 3.6 channel and enable the 3.7 channel on each master and node host:

    # subscription-manager repos --disable="rhel-7-server-ose-3.6-rpms" \
        --enable="rhel-7-server-ose-3.7-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-fast-datapath-rpms"
    # yum clean all
  3. For any upgrade path, always ensure that you have the latest version of the atomic-openshift-utils package on each RHEL 7 system, which also updates the openshift-ansible-* packages:

    # yum update atomic-openshift-utils
  4. Before upgrading to OpenShift Container Platform 3.7, your cluster must be using external etcd (not embedded) and its data must be using the v3 data model:

    1. Starting in OpenShift Container Platform 3.7, embedded etcd is no longer supported. If you have an OpenShift Container Platform 3.6 cluster that is using an embeded etcd, you must run a playbook to migrate it to external etcd. See Migrating Embedded etcd to External etcd for steps.
    2. If your cluster was initially installed using openshift-ansible version 3.6.173.0.21 or later, your etcd data is already using the v3 model. If it was upgraded from OpenShift Container Platform 3.5 to 3.6 before then, you must run a playbook to migrate the data from the v2 model to v3. See Migrating etcd Data (v2 to v3) for steps.

After satisfying these steps, there are two methods for running the automated upgrade:

Choose and follow one of these methods.

5.2.3. Using the Quick Installer to Upgrade

If you installed OpenShift Container Platform using the quick installation method, you should have an installation configuration file located at ~/.config/openshift/installer.cfg.yml. The quick installer requires this file to start an upgrade.

The quick installer supports upgrading between minor versions of OpenShift Container Platform (one minor version at a time, e.g., 3.5 to 3.6) as well as between asynchronous errata updates within a minor version (e.g., 3.6.z).

If you have an older format installation configuration file in ~/.config/openshift/installer.cfg.yml from an installation of a previous cluster version, the quick installer will attempt to upgrade the file to the new supported format. If you do not have an installation configuration file of any format, you can create one manually.

To start an upgrade with the quick installer:

  1. Satisfy the steps in Preparing for an Automated Upgrade to ensure you are using the latest upgrade playbooks.
  2. Run the quick installer with the upgrade subcommand:

    # atomic-openshift-installer upgrade
  3. Then, follow the on-screen instructions to upgrade to the latest release.

    Note

    If the quick installer fails, note the error output and check Known Issues for any additional steps.

  4. After all master and node upgrades have completed, a recommendation will be printed to reboot all hosts. After rebooting, if there are no additional features enabled, you can verify the upgrade. Otherwise, the next step depends on what additional features have you previously enabled.

    FeatureNext Step

    Service Catalog

    Enable and configure the service catalog.

    Aggregated Logging

    Upgrade the EFK logging stack.

    Cluster Metrics

    Upgrade cluster metrics.

5.2.4. Running Upgrade Playbooks Directly

You can run automated upgrade playbooks using Ansible directly, similar to the advanced installation method, if you have an inventory file. Playbooks can be run using the ansible-playbook command.

The same v3_7 upgrade playbooks can be used for either of the following scenarios:

  • Upgrading existing OpenShift Container Platform 3.6 clusters to 3.7
  • Upgrading existing OpenShift Container Platform 3.7 clusters to the latest asynchronous errata updates

5.2.4.1. Upgrading the Control Plane and Nodes in Separate Phases

An OpenShift Container Platform cluster can be upgraded in one or more phases. You can choose whether to upgrade all hosts in one phase by running a single Ansible playbook, or upgrade the control plane (master components) and nodes in multiple phases using separate playbooks.

Note

Instructions on the full upgrade process and when to call these playbooks are described in Upgrading to the Latest OpenShift Container Platform 3.7 Release.

When upgrading in separate phases, the control plane phase includes upgrading:

  • master components
  • node services running on masters
  • Docker running on masters
  • Docker running on any stand-alone etcd hosts

When upgrading only the nodes, the control plane must already be upgraded. The node phase includes upgrading:

  • node services running on stand-alone nodes
  • Docker running on stand-alone nodes
Note

Nodes running master components are not included during the node upgrade phase, even though they have node services and Docker running on them. Instead, they are upgraded as part of the control plane upgrade phase. This ensures node services and Docker on masters are not upgraded twice (once during the control plane phase and again during the node phase).

5.2.4.2. Customizing Node Upgrades

Whether upgrading in a single or multiple phases, you can customize how the node portion of the upgrade progresses by passing certain Ansible variables to an upgrade playbook using the -e option.

Note

Instructions on the full upgrade process and when to call these playbooks are described in Upgrading to the Latest OpenShift Container Platform 3.7 Release.

The openshift_upgrade_nodes_serial variable can be set to an integer or percentage to control how many node hosts are upgraded at the same time. The default is 1, upgrading nodes one at a time.

For example, to upgrade 20 percent of the total number of detected nodes at a time:

$ ansible-playbook -i <path/to/inventory/file> \
    </path/to/upgrade/playbook> \
    -e openshift_upgrade_nodes_serial="20%"

The openshift_upgrade_nodes_label variable allows you to specify that only nodes with a certain label are upgraded. This can also be combined with the openshift_upgrade_nodes_serial variable.

For example, to only upgrade nodes in the group1 region, two at a time:

$ ansible-playbook -i <path/to/inventory/file> \
    </path/to/upgrade/playbook> \
    -e openshift_upgrade_nodes_serial="2" \
    -e openshift_upgrade_nodes_label="region=group1"

See Managing Nodes for more on node labels.

5.2.4.3. Customizing Upgrades With Ansible Hooks

When upgrading OpenShift Container Platform, you can execute custom tasks during specific operations through a system called hooks. Hooks allow cluster administrators to provide files defining tasks to execute before and/or after specific areas during installations and upgrades. This can be very helpful to validate or modify custom infrastructure when installing or upgrading OpenShift Container Platform.

It is important to remember that when a hook fails, the operation fails. This means a good hook can run multiple times and provide the same results. A great hook is idempotent.

5.2.4.3.1. Limitations
  • Hooks have no defined or versioned interface. They can use internal openshift-ansible variables, but there is no guarantee these will remain in future releases. In the future, hooks may be versioned, giving you advance warning that your hook needs to be updated to work with the latest openshift-ansible.
  • Hooks have no error handling, so an error in a hook will halt the upgrade process. The problem will need to be addressed and the upgrade re-run.
5.2.4.3.2. Using Hooks

Hooks are defined in the hosts inventory file under the OSEv3:vars section.

Each hook must point to a YAML file which defines Ansible tasks. This file will be used as an include, meaning that the file cannot be a playbook, but a set of tasks. Best practice suggests using absolute paths to the hook file to avoid any ambiguity.

Example Hook Definitions in an Inventory File

[OSEv3:vars]
openshift_master_upgrade_pre_hook=/usr/share/custom/pre_master.yml
openshift_master_upgrade_hook=/usr/share/custom/master.yml
openshift_master_upgrade_post_hook=/usr/share/custom/post_master.yml

Example pre_master.yml Task

---
# Trivial example forcing an operator to ack the start of an upgrade
# file=/usr/share/custom/pre_master.yml

- name: note the start of a master upgrade
  debug:
      msg: "Master upgrade of {{ inventory_hostname }} is about to start"

- name: require an operator agree to start an upgrade
  pause:
      prompt: "Hit enter to start the master upgrade"

5.2.4.3.3. Available Upgrade Hooks
openshift_master_upgrade_pre_hook
  • Runs before each master is upgraded.
  • This hook runs against each master in serial.
  • If a task must run against a different host, said task must use delegate_to or local_action.
openshift_master_upgrade_hook
  • Runs after each master is upgraded, but before its service or system restart.
  • This hook runs against each master in serial.
  • If a task must run against a different host, said task must use delegate_to or local_action.
openshift_master_upgrade_post_hook
  • Runs after each master is upgraded and has had its service or system restart.
  • This hook runs against each master in serial.
  • If a task must run against a different host, said task must use delegate_to or local_action.

5.2.4.4. Upgrading to the Latest OpenShift Container Platform 3.7 Release

To upgrade an existing OpenShift Container Platform 3.6 or 3.7 cluster to the latest 3.7 release:

  1. Satisfy the steps in Preparing for an Automated Upgrade to ensure you are using the latest upgrade playbooks.

    Important

    Ensure that the steps on etcd v2 to v3 migration are satisfied, which is a special requirement for the OpenShift Container Platform 3.6 to 3.7 upgrade.

  2. Ensure the openshift_deployment_type parameter (formerly called deployment_type) in your inventory file is set to openshift-enterprise.
  3. If you have multiple masters configured and want to enable rolling, full system restarts of the hosts, you can set the openshift_rolling_restart_mode parameter in your inventory file to system. Otherwise, the default value services performs rolling service restarts on HA masters, but does not reboot the systems. See Configuring Cluster Variables for details.
  4. At this point, you can choose to run the upgrade in a single or multiple phases. See Upgrading the Control Plane and Nodes in Separate Phases for more details which components are upgraded in each phase.

    If your inventory file is located somewhere other than the default /etc/ansible/hosts, add the -i flag to specify its location. If you previously used the atomic-openshift-installer command to run your installation, you can check ~/.config/openshift/hosts for the last inventory file that was used, if needed.

    Note

    You can add --tags pre_upgrade to the following ansible-playbook commands to run the pre-upgrade checks for the playbook. This is a dry-run option that preforms all pre-upgrade checks without actually upgrading any hosts, and reports any problems found.

    • Option A) Upgrade control plane and nodes in a single phase.

      Run the upgrade.yml playbook to upgrade the cluster in a single phase using one playbook; the control plane is still upgraded first, then nodes in-place:

      # ansible-playbook -i </path/to/inventory/file> \
          /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/upgrades/v3_7/upgrade.yml
    • Option B) Upgrade the control plane and nodes in separate phases.

      1. To upgrade only the control plane, run the upgrade_control_plane.yaml playbook:

        # ansible-playbook -i </path/to/inventory/file> \
            /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/upgrades/v3_7/upgrade_control_plane.yml
      2. To upgrade only the nodes, run the upgrade_nodes.yaml playbook:

        # ansible-playbook -i </path/to/inventory/file> \
            /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/upgrades/v3_7/upgrade_nodes.yml \
            [-e <customized_node_upgrade_variables>] 1
        1
        See Customizing Node Upgrades for any desired <customized_node_upgrade_variables>.

        If you are upgrading the nodes in groups as described in Customizing Node Upgrades, continue invoking the upgrade_nodes.yml playbook until all nodes have been successfully upgraded.

  5. After all master and node upgrades have completed, a recommendation will be printed to reboot all hosts. After rebooting, if there are no additional features enabled, you can verify the upgrade. Otherwise, the next step depends on what additional features have you previously enabled.

    FeatureNext Step

    Service Catalog

    Enable and configure the service catalog.

    Aggregated Logging

    Upgrade the EFK logging stack.

    Cluster Metrics

    Upgrade cluster metrics.

5.2.5. Upgrading the Service Catalog

Starting with OpenShift Container Platform 3.7, the service catalog, OpenShift Ansible broker, and template service broker are enabled and deployed by default for new cluster installations. However, they are not deployed by default during the upgrade from OpenShift Container Platform 3.6 to 3.7, so you must run an individual component playbook separate post-upgrade.

Note

Upgrading from the OpenShift Container Platform 3.6 Technology Preview version of the service catalog and service brokers is not supported.

To upgrade to these features:

  1. See the following three sections in the Advanced Installation topic and update your inventory file accordingly:

  2. Run the following playbook:

    # ansible-playbook -i </path/to/inventory/file> \
        /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/service-catalog.yml

5.2.6. Upgrading the EFK Logging Stack

To upgrade an existing EFK logging stack deployment, you must use the provided /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-logging.yml Ansible playbook. This is the playbook to use if you were deploying logging for the first time on an existing cluster, but is also used to upgrade existing logging deployments.

  1. If you have not already done so, see Specifying Logging Ansible Variables in the Aggregating Container Logs topic and update your Ansible inventory file to at least set the following required variable within the [OSEv3:vars] section:

    [OSEv3:vars]
    
    openshift_logging_install_logging=true 1
    openshift_logging_image_version=<tag> 2
    1
    Enables the ability to upgrade the logging stack.
    2
    Replace <tag> with v3.7.9 for the latest version.
  2. Add any other openshift_logging_* variables that you want to specify to override the defaults, as described in Specifying Logging Ansible Variables.
  3. When you have finished updating your inventory file, follow the instructions in Deploying the EFK Stack to run the openshift-logging.yml playbook and complete the logging deployment upgrade.

5.2.7. Upgrading Cluster Metrics

To upgrade an existing cluster metrics deployment, you must use the provided /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-metrics.yml Ansible playbook. This is the playbook to use if you were deploying metrics for the first time on an existing cluster, but is also used to upgrade existing metrics deployments.

  1. If you have not already done so, see Specifying Metrics Ansible Variables in the Enabling Cluster Metrics topic and update your Ansible inventory file to at least set the following required variables within the [OSEv3:vars] section:

    [OSEv3:vars]
    
    openshift_metrics_install_metrics=true 1
    openshift_metrics_image_version=<tag> 2
    openshift_metrics_hawkular_hostname=<fqdn> 3
    openshift_metrics_cassandra_storage_type=(emptydir|pv|dynamic) 4
    1
    Enables the ability to upgrade the metrics deployment.
    2
    Replace <tag> with v3.7.9 for the latest version.
    3
    Used for the Hawkular Metrics route. Should correspond to a fully qualified domain name.
    4
    Choose a type that is consistent with the previous deployment.
  2. Add any other openshift_metrics_* variables that you want to specify to override the defaults, as described in Specifying Metrics Ansible Variables.
  3. When you have finished updating your inventory file, follow the instructions in Deploying the Metrics Deployment to run the openshift_metrics.yml playbook and complete the metrics deployment upgrade.

5.2.8. Verifying the Upgrade

To verify the upgrade:

  1. Check that all nodes are marked as Ready:

    # oc get nodes
    NAME                        STATUS                     AGE
    master.example.com          Ready,SchedulingDisabled   165d
    node1.example.com           Ready                      165d
    node2.example.com           Ready                      165d
  2. Verify that you are running the expected versions of the docker-registry and router images, if deployed. Replace <tag> with v3.7.9 for the latest version.

    # oc get -n default dc/docker-registry -o json | grep \"image\"
        "image": "openshift3/ose-docker-registry:<tag>",
    # oc get -n default dc/router -o json | grep \"image\"
        "image": "openshift3/ose-haproxy-router:<tag>",
  3. Use the diagnostics tool on the master to look for common issues:

    # oc adm diagnostics
    ...
    [Note] Summary of diagnostics execution:
    [Note] Completed with no errors or warnings seen.

5.3. Performing Manual In-place Cluster Upgrades

5.3.1. Overview

As an alternative to performing an automated upgrade, you can manually upgrade your OpenShift Container Platform cluster. To manually upgrade without disruption, it is important to upgrade each component as documented in this topic.

Before you begin your upgrade, familiarize yourself now with the entire procedure. Specific releases may require additional steps to be performed at key points before or during the standard upgrade process.

Important

Ensure that you have met all prerequisites before proceeding with an upgrade. Failure to do so can result in a failed upgrade.

5.3.2. Preparing for a Manual Upgrade

Note

Before upgrading your cluster to OpenShift Container Platform 3.7, the cluster must be already upgraded to the latest asynchronous release of version 3.6. Cluster upgrades cannot span more than one minor version at a time, so if your cluster is at a version earlier than 3.6, you must first upgrade incrementally (e.g., 3.4 to 3.5, then 3.5 to 3.6).

Note

Before attempting the upgrade, follow the steps in Verifying the Upgrade to verify the cluster’s health. This will confirm that nodes are in the Ready state, running the expected starting version, and will ensure that there are no diagnostic errors or warnings.

To prepare for a manual upgrade, follow these steps:

  1. Pull the latest subscription data from RHSM:

    # subscription-manager refresh
  2. If you are upgrading from OpenShift Container Platform 3.6 to 3.7, manually disable the 3.6 channel and enable the 3.7 channel on each host:

    # subscription-manager repos --disable="rhel-7-server-ose-3.6-rpms" \
        --enable="rhel-7-server-ose-3.7-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-fast-datapath-rpms"

    On RHEL 7 systems, also clear the yum cache:

    # yum clean all
  3. Install or update to the latest available version of the atomic-openshift-utils package on each RHEL 7 system, which provides files that will be used in later sections:

    # yum install atomic-openshift-utils
  4. Install or update to the following latest available *-excluder packages on each RHEL 7 system, which helps ensure your systems stay on the correct versions of atomic-openshift and docker packages when you are not trying to upgrade, according to the OpenShift Container Platform version:

    # yum install atomic-openshift-excluder atomic-openshift-docker-excluder

    These packages add entries to the exclude directive in the host’s /etc/yum.conf file.

  5. Create an etcd backup on each master. The etcd package is required, even if using embedded etcd, for access to the etcdctl command to make the backup.

    Note

    The etcd package is installed by default for RHEL Atomic Host 7 systems. If the master is a RHEL 7 system and etcd is not already installed, install it now:

    # yum install etcd

    To create the backup, run:

    # ETCD_DATA_DIR=/var/lib/etcd 1
    # etcdctl backup \
        --data-dir $ETCD_DATA_DIR \
        --backup-dir $ETCD_DATA_DIR.bak.<date> 2
    1
    This directory is for external etcd.
    2
    Use the date of the backup, or some unique identifier, for <date>. The command will not make a backup if the --backup-dir location already exists.
  6. For any upgrade path, ensure that you are running the latest kernel on each RHEL 7 system:

    # yum update kernel
  7. There is a small set of configurations that are possible in authorization policy resources in OpenShift Container Platform 3.6 that are not supported by RBAC in OpenShift Container Platform 3.7. Such configurations require manual migration based on your use case.

    If you are upgrading from OpenShift Container Platform 3.6 to 3.7, to guarantee that all authorization policy objects are in sync with RBAC, run:

    $ oc adm migrate authorization

    This read-only command emulates the migration controller logic and reports if any resource is out of sync.

    Important

    During a rolling upgrade, avoid actions that require changes to OpenShift Container Platform authorization policy resources such as the creation of new projects. If a project is created against a new master, the RBAC resources it creates will be deleted by the migration controller since they will be seen as out of sync from the authorization policy resources.

    If a project is created against an old master and the migration controller is no longer present due to a OpenShift Container Platform 3.7 controller process being the leader, then its policy objects will not be synced and it will have no RBAC resources.

5.3.3. Upgrading Master Components

Before upgrading any stand-alone nodes, upgrade the master components (which provide the control plane for the cluster).

  1. Run the following command on each master to remove the atomic-openshift packages from the list of yum excludes on the host:

    # atomic-openshift-excluder unexclude
  2. Upgrade etcd on all master hosts and any external etcd hosts.

    1. For RHEL 7 systems using the RPM-based method:

      1. Upgrade the etcd package:

        # yum update etcd
      2. Restart the etcd service and review the logs to ensure it restarts successfully:

        # systemctl restart etcd
        # journalctl -r -u etcd
    2. For RHEL Atomic Host 7 systems and RHEL 7 systems using the containerized method:

      1. Pull the latest rhel7/etcd image:

        # docker pull registry.access.redhat.com/rhel7/etcd
      2. Restart the etcd_container service and review the logs to ensure it restarts successfully:

        # systemctl restart etcd_container
        # journalctl -r -u etcd_container
  3. On each master host, upgrade the atomic-openshift packages or related images.

    1. For masters using the RPM-based method on a RHEL 7 system, upgrade all installed atomic-openshift packages and the openvswitch package:

      # yum upgrade atomic-openshift\* openvswitch
    2. For masters using the containerized method on a RHEL 7 or RHEL Atomic Host 7 system, set the IMAGE_VERSION parameter to the version you are upgrading to in the following files:

      • /etc/sysconfig/atomic-openshift-master (single master clusters only)
      • /etc/sysconfig/atomic-openshift-master-controllers (multi-master clusters only)
      • /etc/sysconfig/atomic-openshift-master-api (multi-master clusters only)
      • /etc/sysconfig/atomic-openshift-node
      • /etc/sysconfig/atomic-openshift-openvswitch

      For example:

      IMAGE_VERSION=<tag>

      Replace <tag> with v3.7.9 for the latest version.

  4. Restart the master service(s) on each master and review logs to ensure they restart successfully.

    For single master clusters:

    # systemctl restart atomic-openshift-master
    # journalctl -r -u atomic-openshift-master

    For multi-master clusters:

    # systemctl restart atomic-openshift-master-controllers
    # systemctl restart atomic-openshift-master-api
    # journalctl -r -u atomic-openshift-master-controllers
    # journalctl -r -u atomic-openshift-master-api
  5. Because masters also have node components running on them in order to be configured as part of the OpenShift SDN, restart the atomic-openshift-node and openvswitch services:

    # systemctl restart openvswitch
    # systemctl restart atomic-openshift-node
    # journalctl -r -u openvswitch
    # journalctl -r -u atomic-openshift-node
  6. If you are performing a cluster upgrade that requires updating Docker to version 1.12, you must also perform the following steps if you are not already on Docker 1.12:

    Important

    The node component on masters is set by default to unschedulable status during initial installation, so that pods are not deployed to them. However, it is possible to set them schedulable during the initial installation or manually thereafter. If any of your masters are also configured as a schedulable node, skip the following Docker upgrade steps for those masters and instead run all steps described in Upgrading Nodes when you get to that section for those hosts as well.

    1. Upgrade the docker package.

      1. For RHEL 7 systems:

        # yum update docker

        Then, restart the docker service and review the logs to ensure it restarts successfully:

        # systemctl restart docker
        # journalctl -r -u docker
      2. For RHEL Atomic Host 7 systems, upgrade to the latest Atomic tree if one is available:

        Note

        If upgrading to RHEL Atomic Host 7.4.2, this upgrades Docker to version 1.12.

        # atomic host upgrade
    2. After the upgrade is completed and prepared for the next boot, reboot the host and ensure the docker service starts successfully:

      # systemctl reboot
      # journalctl -r -u docker
    3. Remove the following file, which is no longer required:

      # rm /etc/systemd/system/docker.service.d/docker-sdn-ovs.conf
  7. Run the following command on each master to add the atomic-openshift packages back to the list of yum excludes on the host:

    # atomic-openshift-excluder exclude
Note

During the cluster upgrade, it can sometimes be useful to take a master out of rotation since some DNS client libraries will not properly to the other masters for cluster DNS. In addition to stopping the master and controller services, you can remove the EndPoint from the Kubernetes service’s subsets.addresses.

$ oc edit ep/kubernetes -n default

When the master is restarted, the Kubernetes service will be automatically updated.

5.3.4. Updating Policy Definitions

After a cluster upgrade, the default roles default cluster roles are automatically updated. To check if all defaults are set as recommended for your environment, run:

# oadm policy reconcile-cluster-roles
Warning

If you have customized default cluster roles and want to ensure a role reconciliation does not modify those customized roles, annotate them with openshift.io/reconcile-protect set to true when using the old Openshift policy format. When using the new RBAC roles, use rbac.authorization.kubernetes.io/autoupdate set to false instead. In doing so, you are responsible for manually updating those roles with any new or required permissions during upgrades.

This command outputs a list of roles that are out of date and their new proposed values. For example:

# oadm policy reconcile-cluster-roles
apiVersion: v1
items:
- apiVersion: v1
  kind: ClusterRole
  metadata:
    creationTimestamp: null
    name: admin
  rules:
  - attributeRestrictions: null
    resources:
    - builds/custom
...
Note

Your output will vary based on the OpenShift version and any local customizations you have made. Review the proposed policy carefully.

You can either modify this output to re-apply any local policy changes you have made, or you can automatically apply the new policy using the following process:

  1. Reconcile the cluster roles:

    # oadm policy reconcile-cluster-roles \
        --additive-only=true \
        --confirm
  2. Reconcile the cluster role bindings:

    # oadm policy reconcile-cluster-role-bindings \
        --exclude-groups=system:authenticated \
        --exclude-groups=system:authenticated:oauth \
        --exclude-groups=system:unauthenticated \
        --exclude-users=system:anonymous \
        --additive-only=true \
        --confirm

    Also run:

    # oadm policy reconcile-cluster-role-bindings \
        system:build-strategy-jenkinspipeline \
        --confirm \
        -o name
  3. Reconcile security context constraints:

    # oadm policy reconcile-sccs \
        --additive-only=true \
        --confirm

5.3.5. Upgrading Nodes

After upgrading your masters, you can upgrade your nodes. When restarting the atomic-openshift-node service, there will be a brief disruption of outbound network connectivity from running pods to services while the service proxy is restarted. The length of this disruption should be very short and scales based on the number of services in the entire cluster.

Note

You can alternatively use the blue-green deployment method at this point to create a parallel environment for new nodes instead of upgrading them in place.

One at at time for each node that is not also a master, you must disable scheduling and evacuate its pods to other nodes, then upgrade packages and restart services.

  1. Run the following command on each node to remove the atomic-openshift packages from the list of yum excludes on the host:

    # atomic-openshift-excluder unexclude
  2. As a user with cluster-admin privileges, disable scheduling for the node:

    # oadm manage-node <node> --schedulable=false
  3. Evacuate pods on the node to other nodes:

    Important

    The --force option deletes any pods that are not backed by a replication controller.

    # oadm drain <node> --force --delete-local-data --ignore-daemonsets
  4. Upgrade the node component packages or related images.

    1. For nodes using the RPM-based method on a RHEL 7 system, upgrade all installed atomic-openshift packages and the openvswitch package:

      # yum upgrade atomic-openshift\* openvswitch
    2. For nodes using the containerized method on a RHEL 7 or RHEL Atomic Host 7 system, set the IMAGE_VERSION parameter in the /etc/sysconfig/atomic-openshift-node and /etc/sysconfig/openvswitch files to the version you are upgrading to. For example:

      IMAGE_VERSION=<tag>

      Replace <tag> with v3.7.9 for the latest version.

  5. Restart the atomic-openshift-node and openvswitch services and review the logs to ensure they restart successfully:

    # systemctl restart openvswitch
    # systemctl restart atomic-openshift-node
    # journalctl -r -u atomic-openshift-node
    # journalctl -r -u openvswitch
  6. If you are performing a cluster upgrade that requires updating Docker to version 1.12, you must also perform the following steps if you are not already on Docker 1.12:

    1. Upgrade the docker package.

      1. For RHEL 7 systems:

        # yum update docker

        Then, restart the docker service and review the logs to ensure it restarts successfully:

        # systemctl restart docker
        # journalctl -r -u docker

        After Docker is restarted, restart the atomic-openshift-node service again and review the logs to ensure it restarts successfully:

        # systemctl restart atomic-openshift-node
        # journalctl -r -u atomic-openshift-node
      2. For RHEL Atomic Host 7 systems, upgrade to the latest Atomic tree if one is available:

        Note

        If upgrading to RHEL Atomic Host 7.4.2, this upgrades Docker to version 1.12.

        # atomic host upgrade

        After the upgrade is completed and prepared for the next boot, reboot the host and ensure the docker service starts successfully:

        # systemctl reboot
        # journalctl -r -u docker
    2. Remove the following file, which is no longer required:

      # rm /etc/systemd/system/docker.service.d/docker-sdn-ovs.conf
  7. Re-enable scheduling for the node:

    # oadm manage-node <node> --schedulable
  8. Run the following command on each node to add the atomic-openshift packages back to the list of yum excludes on the host:

    # atomic-openshift-excluder exclude
  9. Repeat the previous steps on the next node, and continue repeating these steps until all nodes have been upgraded.
  10. After all nodes have been upgraded, as a user with cluster-admin privileges, verify that all nodes are showing as Ready:

    # oc get nodes
    NAME                        STATUS                     AGE
    master.example.com          Ready,SchedulingDisabled   165d
    node1.example.com           Ready                      165d
    node2.example.com           Ready                      165d

5.3.6. Upgrading the Router

If you have previously deployed a router, the router deployment configuration must be upgraded to apply updates contained in the router image. To upgrade your router without disrupting services, you must have previously deployed a highly-available routing service.

Edit your router’s deployment configuration. For example, if it has the default router name:

# oc edit dc/router

Apply the following changes:

...
spec:
 template:
    spec:
      containers:
      - env:
        ...
        image: registry.access.redhat.com/openshift3/ose-haproxy-router:<tag> 1
        imagePullPolicy: IfNotPresent
        ...
1
Adjust <tag> to match the version you are upgrading to (use v3.7.9 for the latest version).

You should see one router pod updated and then the next.

5.3.7. Upgrading the Registry

The registry must also be upgraded for changes to take effect in the registry image. If you have used a PersistentVolumeClaim or a host mount point, you may restart the registry without losing the contents of your registry. Storage for the Registry details how to configure persistent storage for the registry.

Edit your registry’s deployment configuration:

# oc edit dc/docker-registry

Apply the following changes:

...
spec:
 template:
    spec:
      containers:
      - env:
        ...
        image: registry.access.redhat.com/openshift3/ose-docker-registry:<tag> 1
        imagePullPolicy: IfNotPresent
        ...
1
Adjust <tag> to match the version you are upgrading to (use v3.7.9 for the latest version).

If the registry console is deployed, edit its deployment configuration:

# oc edit dc/registry-console

Apply the following changes:

...
spec:
 template:
    spec:
      containers:
      - env:
        ...
        image: registry.access.redhat.com/openshift3/registry-console:v3.7
        imagePullPolicy: IfNotPresent
        ...
Important

Images that are being pushed or pulled from the internal registry at the time of upgrade will fail and should be restarted automatically. This will not disrupt pods that are already running.

5.3.8. Updating the Default Image Streams and Templates

By default, the quick and advanced installation methods automatically create default image streams, InstantApp templates, and database service templates in the openshift project, which is a default project to which all users have view access. These objects were created during installation from the JSON files located under the /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/ directory.

Note

Because RHEL Atomic Host 7 cannot use yum to update packages, the following steps must take place on a RHEL 7 system.

Update the packages that provide the example JSON files. On a subscribed Red Hat Enterprise Linux 7 system where you can run the CLI as a user with cluster-admin permissions, install or update to the latest version of the atomic-openshift-utils package, which should also update the openshift-ansible- packages:

# yum update atomic-openshift-utils

To persist /usr/share/openshift/examples/ on the first master:

$ scp -R /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/* user@master1:/usr/share/openshift/examples/

To persist /usr/share/openshift/examples/ on all masters:

$ mkdir /usr/share/openshift/examples
$ scp -R /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/* user@masterx:/usr/share/openshift/examples

The openshift-ansible-roles package provides the latest example JSON files.

  1. After a manual upgrade, get the latest templates from openshift-ansible-roles:

    # rpm -ql openshift-ansible-roles | grep examples | grep v3.7

    In this example, /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/image-streams/image-streams-rhel7.json is the latest file that you want in the latest openshift-ansible-roles package.

    /usr/share/openshift/examples/image-streams/image-streams-rhel7.json is not owned by a package, but is updated by Ansible. If you are upgrading outside of Ansible. you need to get the latest .json files on the system where you are running oc, which can run anywhere that has access to the master.

  2. Install atomic-openshift-utils and its dependencies to install the new content into /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/.:

    $ oc create -n openshift -f  /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/image-streams/image-streams-rhel7.json
    $ oc create -n openshift -f  /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/image-streams/dotnet_imagestreams.json
    $ oc replace -n openshift -f  /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/image-streams/image-streams-rhel7.json
    $ oc replace -n openshift -f  /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/image-streams/dotnet_imagestreams.json
  3. Update the templates:

    $ oc create -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/
    $ oc create -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/db-templates/
    $ oc create -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/infrastructure-templates/
    $ oc create -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/xpaas-templates/
    $ oc create -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/xpaas-streams/
    $ oc replace -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/
    $ oc replace -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/db-templates/
    $ oc replace -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/infrastructure-templates/
    $ oc replace -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/xpaas-templates/
    $ oc replace -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/xpaas-streams/

    Errors are generated for items that already exist. This is expected behavior:

    # oc create -n openshift -f /usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/
    Error from server: error when creating "/usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/cakephp-mysql.json": templates "cakephp-mysql-example" already exists
    Error from server: error when creating "/usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/cakephp.json": templates "cakephp-example" already exists
    Error from server: error when creating "/usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/dancer-mysql.json": templates "dancer-mysql-example" already exists
    Error from server: error when creating "/usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/dancer.json": templates "dancer-example" already exists
    Error from server: error when creating "/usr/share/ansible/openshift-ansible/roles/openshift_examples/files/examples/v3.7/quickstart-templates/django-postgresql.json": templates "django-psql-example" already exists

Now, content can be updated. Without running the automated upgrade playbooks, the content is not updated in /usr/share/openshift/.

5.3.9. Importing the Latest Images

After updating the default image streams, you may also want to ensure that the images within those streams are updated. For each image stream in the default openshift project, you can run:

# oc import-image -n openshift <imagestream>

For example, get the list of all image streams in the default openshift project:

# oc get is -n openshift
NAME     DOCKER REPO                                                      TAGS                   UPDATED
mongodb  registry.access.redhat.com/openshift3/mongodb-24-rhel7           2.4,latest,v3.1.1.6    16 hours ago
mysql    registry.access.redhat.com/openshift3/mysql-55-rhel7             5.5,latest,v3.1.1.6    16 hours ago
nodejs   registry.access.redhat.com/openshift3/nodejs-010-rhel7           0.10,latest,v3.1.1.6   16 hours ago
...

Update each image stream one at a time:

# oc import-image -n openshift nodejs
The import completed successfully.

Name:			nodejs
Created:		10 seconds ago
Labels:			<none>
Annotations:		openshift.io/image.dockerRepositoryCheck=2016-07-05T19:20:30Z
Docker Pull Spec:	172.30.204.22:5000/openshift/nodejs

Tag	Spec								Created		PullSpec						Image
latest	4								9 seconds ago	registry.access.redhat.com/rhscl/nodejs-4-rhel7:latest	570ad8ed927fd5c2c9554ef4d9534cef808dfa05df31ec491c0969c3bd372b05
4	registry.access.redhat.com/rhscl/nodejs-4-rhel7:latest		9 seconds ago	<same>							570ad8ed927fd5c2c9554ef4d9534cef808dfa05df31ec491c0969c3bd372b05
0.10	registry.access.redhat.com/openshift3/nodejs-010-rhel7:latest	9 seconds ago	<same>							a1ef33be788a28ec2bdd48a9a5d174ebcfbe11c8e986d2996b77f5bccaaa4774
Important

In order to update your S2I-based applications, you must manually trigger a new build of those applications after importing the new images using oc start-build <app-name>.

5.3.10. Upgrading the Service Catalog

Note

Manual upgrade steps for the service catalog and service brokers are not available.

Starting with OpenShift Container Platform 3.7, the service catalog, OpenShift Ansible broker, and template service broker are enabled and deployed by default for new cluster installations. However, they are not deployed by default during the upgrade from OpenShift Container Platform 3.6 to 3.7, so you must run an individual component playbook separate post-upgrade.

Note

Upgrading from the OpenShift Container Platform 3.6 Technology Preview version of the service catalog and service brokers is not supported.

To upgrade to these features:

  1. See the following three sections in the Advanced Installation topic and update your inventory file accordingly:

  2. Run the following playbook:

    # ansible-playbook -i </path/to/inventory/file> \
        /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/service-catalog.yml

5.3.11. Upgrading the EFK Logging Stack

Note

Manual upgrade steps for logging deployments are no longer available starting in OpenShift Container Platform 3.5.

To upgrade an existing EFK logging stack deployment, you must use the provided /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-logging.yml Ansible playbook. This is the playbook to use if you were deploying logging for the first time on an existing cluster, but is also used to upgrade existing logging deployments.

  1. If you have not already done so, see Specifying Logging Ansible Variables in the Aggregating Container Logs topic and update your Ansible inventory file to at least set the following required variable within the [OSEv3:vars] section:

    [OSEv3:vars]
    
    openshift_logging_install_logging=true 1
    openshift_logging_image_version=<tag> 2
    1
    Enables the ability to upgrade the logging stack.
    2
    Replace <tag> with v3.7.9 for the latest version.
  2. Add any other openshift_logging_* variables that you want to specify to override the defaults, as described in Specifying Logging Ansible Variables.
  3. When you have finished updating your inventory file, follow the instructions in Deploying the EFK Stack to run the openshift-logging.yml playbook and complete the logging deployment upgrade.

5.3.12. Upgrading Cluster Metrics

Note

Manual upgrade steps for metrics deployments are no longer available starting in OpenShift Container Platform 3.5.

To upgrade an existing cluster metrics deployment, you must use the provided /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-cluster/openshift-metrics.yml Ansible playbook. This is the playbook to use if you were deploying metrics for the first time on an existing cluster, but is also used to upgrade existing metrics deployments.

  1. If you have not already done so, see Specifying Metrics Ansible Variables in the Enabling Cluster Metrics topic and update your Ansible inventory file to at least set the following required variables within the [OSEv3:vars] section:

    [OSEv3:vars]
    
    openshift_metrics_install_metrics=true 1
    openshift_metrics_image_version=<tag> 2
    openshift_metrics_hawkular_hostname=<fqdn> 3
    openshift_metrics_cassandra_storage_type=(emptydir|pv|dynamic) 4
    1
    Enables the ability to upgrade the metrics deployment.
    2
    Replace <tag> with v3.7.9 for the latest version.
    3
    Used for the Hawkular Metrics route. Should correspond to a fully qualified domain name.
    4
    Choose a type that is consistent with the previous deployment.
  2. Add any other openshift_metrics_* variables that you want to specify to override the defaults, as described in Specifying Metrics Ansible Variables.
  3. When you have finished updating your inventory file, follow the instructions in Deploying the Metrics Deployment to run the openshift_metrics.yml playbook and complete the metrics deployment upgrade.

5.3.13. Additional Manual Steps Per Release

Some OpenShift Container Platform releases may have additional instructions specific to that release that must be performed to fully apply the updates across the cluster. This section will be updated over time as new asynchronous updates are released for OpenShift Container Platform 3.7.

See the OpenShift Container Platform 3.7 Release Notes to review the latest release notes.

5.3.14. Verifying the Upgrade

To verify the upgrade:

  1. Check that all nodes are marked as Ready:

    # oc get nodes
    NAME                        STATUS                     AGE
    master.example.com          Ready,SchedulingDisabled   165d
    node1.example.com           Ready                      165d
    node2.example.com           Ready                      165d
  2. Verify that you are running the expected versions of the docker-registry and router images, if deployed. Replace <tag> with v3.7.9 for the latest version.

    # oc get -n default dc/docker-registry -o json | grep \"image\"
        "image": "openshift3/ose-docker-registry:<tag>",
    # oc get -n default dc/router -o json | grep \"image\"
        "image": "openshift3/ose-haproxy-router:<tag>",
  3. If you upgraded from OpenShift Container Platform 3.6 to 3.7, the following read-only script can be used to determine what namespaces lack RBAC role bindings:

    #!/bin/bash
    
    set -o errexit
    set -o nounset
    set -o pipefail
    
    for namespace in $(oc get namespace -o name); do
        ns=$(echo "${namespace}" | cut -d / -f 2)
        rolebindings_count=$(oc get rolebinding.rbac -o name -n "${ns}" | wc -l)
        if [[ "${rolebindings_count}" == "0" ]]; then
            echo "Namespace ${ns} has no role bindings which may require further investigation"
        else
            echo "Namespace ${ns}: ok"
        fi
    done

    It is up to you to decide how to remediate these namespaces.

  4. Use the diagnostics tool on the master to look for common issues:

    # oadm diagnostics
    ...
    [Note] Summary of diagnostics execution:
    [Note] Completed with no errors or warnings seen.

5.4. Blue-Green Deployments

5.4.1. Overview

Note

This topic serves as an alternative approach for node host upgrades to the in-place upgrade method.

The blue-green deployment upgrade method follows a similar flow to the in-place method: masters and etcd servers are still upgraded first, however a parallel environment is created for new node hosts instead of upgrading them in-place.

This method allows administrators to switch traffic from the old set of node hosts (e.g., the blue deployment) to the new set (e.g., the green deployment) after the new deployment has been verified. If a problem is detected, it is also then easy to rollback to the old deployment quickly.

While blue-green is a proven and valid strategy for deploying just about any software, there are always trade-offs. Not all environments have the same uptime requirements or the resources to properly perform blue-green deployments.

In an OpenShift Container Platform environment, the most suitable candidate for blue-green deployments are the node hosts. All user processes run on these systems and even critical pieces of OpenShift Container Platform infrastructure are self-hosted on these resources. Uptime is most important for these workloads and the additional complexity of blue-green deployments can be justified.

The exact implementation of this approach varies based on your requirements. Often the main challenge is having the excess capacity to facilitate such an approach.

Figure 5.1. Blue-Green Deployment

Blue-Green Deployment Upgrade

5.4.2. Preparing for a Blue-Green Upgrade

After you have upgraded your master and etcd hosts using method described for In-place Upgrades, use the following sections to prepare your environment for a blue-green upgrade of the remaining node hosts.

5.4.2.1. Sharing Software Entitlements

Administrators must temporarily share the Red Hat software entitlements between the blue-green deployments or provide access to the installation content by means of a system such as Red Hat Satellite. This can be accomplished by sharing the consumer ID from the previous node host:

  1. On each old node host that will be upgraded, note its system identity value, which is the consumer ID:

    # subscription-manager identity | grep system
    system identity: 6699375b-06db-48c4-941e-689efd6ce3aa
  2. On each new RHEL 7 or RHEL Atomic Host 7 system that is going to replace an old node host, register using the respective consumer ID from the previous step:

    # subscription-manager register --consumerid=6699375b-06db-48c4-941e-689efd6ce3aa
Important

After a successful deployment, remember to unregister the old host with subscription-manager clean to prevent the environment from being out of compliance.

5.4.2.2. Labeling Blue Nodes

You must ensure that your current node hosts in production are labeled either blue or green. In this example, the current production environment will be blue and the new environment will be green.

  1. Get the current list of node names known to the cluster:

    $ oc get nodes
  2. Ensure that all hosts have appropriate node labels. Consider that by default, all master hosts are also configured as unschedulable node hosts (so that they are joined to the pod network). Additional labels will assist in management of clusters, specifically labeling hosts as their types (e.g., type=master or type=node) should assist management.

    For example, to label node hosts that are also masters as type=master, run the following for each relevant <node_name>:

    $ oc label node <node_name> type=master

    To label non-master node hosts as type=node, run the following for each relevant <node_name>:

    $ oc label node <node_name> type=node

    Alternatively, if you have already finished labeling certain nodes with type=master and just want to label all remaining nodes as type=node, you can use the --all option and any hosts that already had a type= set will not be overwritten:

    $ oc label node --all type=node
  3. Label all non-master node hosts in your current production environment to color=blue. For example, using the labels described in the previous step:

    $ oc label node -l type=node color=blue

    In the above command, the -l flag is used to match a subset of the environment using the selector type=node, and all matches are labeled with color=blue.

5.4.2.3. Creating and Labeling Green Nodes

Create the new green environment for any node hosts that are to be replaced by adding an equal number of new node hosts to the existing cluster. You can use either the quick installer or advanced install method as described in Adding Hosts to an Existing Cluster.

When adding these new nodes, use the following Ansible variables:

  • Apply the color=green label automatically during the installation of these hosts by setting the openshift_node_labels variable for each node host. You can always adjust the labels after installation as well, if needed, using the oc label node command.
  • In order to delay workload scheduling until the nodes are deemed healthy (which you will verify in later steps), set the openshift_schedulable=false variable for each node host to ensure they are unschedulable initially.

Example new_nodes Host Group

Add the following to your existing inventory. Everything that was in your inventory previously should remain.

[new_nodes]
node4.example.com openshift_node_labels="{'region': 'primary', 'color':'green'}" openshift_schedulable=false
node5.example.com openshift_node_labels="{'region': 'primary', 'color':'green'}" openshift_schedulable=false
node6.example.com openshift_node_labels="{'region': 'primary', 'color':'green'}" openshift_schedulable=false
infra-node3.example.com openshift_node_labels="{'region': 'infra', 'color':'green'}" openshift_schedulable=false
infra-node4.example.com openshift_node_labels="{'region': 'infra', 'color':'green'}" openshift_schedulable=false

5.4.2.4. Verifying Green Nodes

Verify that your new green nodes are in a healthy state. Perform the following checklist:

  1. Verify that new nodes are detected in the cluster and are in Ready state:

    $ oc get nodes
    
    ip-172-31-49-10.ec2.internal    Ready                      3d
  2. Verify that the green nodes have proper labels:

    $ oc get nodes -o wide --show-labels
    
    ip-172-31-49-10.ec2.internal    Ready                      4d        beta.kubernetes.io/arch=amd64,beta.kubernetes.io/instance-type=m4.large,beta.kubernetes.io/os=linux,color=green,failure-domain.beta.kubernetes.io/region=us-east-1,failure-domain.beta.kubernetes.io/zone=us-east-1c,hostname=openshift-cluster-1d005,kubernetes.io/hostname=ip-172-31-49-10.ec2.internal,region=us-east-1,type=infra
  3. Perform a diagnostic check for the cluster:

    $ oadm diagnostics
    
    [Note] Determining if client configuration exists for client/cluster diagnostics
    Info:  Successfully read a client config file at '/root/.kube/config'
    Info:  Using context for cluster-admin access: 'default/internal-api-upgradetest-openshift-com:443/system:admin'
    [Note] Performing systemd discovery
    
    [Note] Running diagnostic: ConfigContexts[default/api-upgradetest-openshift-com:443/system:admin]
           Description: Validate client config context is complete and has connectivity
    ...
             [Note] Running diagnostic: CheckExternalNetwork
                  Description: Check that external network is accessible within a pod
    
           [Note] Running diagnostic: CheckNodeNetwork
                  Description: Check that pods in the cluster can access its own node.
    
           [Note] Running diagnostic: CheckPodNetwork
                  Description: Check pod to pod communication in the cluster. In case of ovs-subnet network plugin, all pods
    should be able to communicate with each other and in case of multitenant network plugin, pods in non-global projects
    should be isolated and pods in global projects should be able to access any pod in the cluster and vice versa.
    
           [Note] Running diagnostic: CheckServiceNetwork
                  Description: Check pod to service communication in the cluster. In case of ovs-subnet network plugin, all
    pods should be able to communicate with all services and in case of multitenant network plugin, services in non-global
    projects should be isolated and pods in global projects should be able to access any service in the cluster.
    ...

5.4.3. Registry and Router Canary Deployments

A common practice is to scale the registry and router pods until they are migrated to new (green) infrastructure node hosts. For these pods, a canary deployment approach is commonly used.

Scaling these pods up will make them immediately active on the new infrastructure nodes. Pointing their deployment configuration to the new image initiates a rolling update. However, because of node anti-affinity, and the fact that the blue nodes are still unschedulable, the deployments to the old nodes will fail.

At this point, the registry and router deployments can be scaled down to the original number of pods. At any given point, the original number of pods is still available so no capacity is lost and downtime should be avoided.

5.4.4. Warming the Green Nodes

In order for pods to be migrated from the blue environment to the green, the required container images must be pulled. Network latency and load on the registry can cause delays if there is not sufficient capacity built in to the environment.

Often, the best way to minimize impact to the running system is to trigger new pod deployments that will land on the new nodes. Accomplish this by importing new image streams.

Major releases of OpenShift Container Platform (and sometimes asynchronous errata updates) introduce new image streams for builder images for users of Source-to-Image (S2I). Upon import, any builds or deployments configured with image change triggers are automatically created.

Another benefit of triggering the builds is that it does a fairly good job of fetching the majority of the ancillary images to all node hosts such as the various builder images, the pod infrastructure image, and deployers. Everything else can be moved over using node evacuation in a later step and will proceed more quickly as a result.

When you are ready to continue with the upgrade process, follow these steps to warm the green nodes:

  1. Disable the blue nodes so that no new pods are run on them by setting them unschedulable:

    $ oadm manage-node --schedulable=false --selector=color=blue
  2. Set the green nodes to schedulable so that new pods only land on them:

    $ oadm manage-node --schedulable=true --selector=color=green
  3. Update the default image streams and templates as described in Manual In-place Upgrades.
  4. Import the latest images as described in Manual In-place Upgrades.

    It is important to realize that this process can trigger a large number of builds. The good news is that the builds are performed on the green nodes and, therefore, do not impact any traffic on the blue deployment.

  5. To monitor build progress across all namespaces (projects) in the cluster:

    $ oc get events -w --all-namespaces

    In large environments, builds rarely completely stop. However, you should see a large increase and decrease caused by the administrative image import.

5.4.5. Evacuating and Decommissioning Blue Nodes

For larger deployments, it is possible to have other labels that help determine how evacuation can be coordinated. The most conservative approach for avoiding downtime is to evacuate one node host at a time.

If services are composed of pods using zone anti-affinity, then an entire zone can be evacuated at once. It is important to ensure that the storage volumes used are available in the new zone as this detail can vary among cloud providers.

In OpenShift Container Platform 3.2 and later, a node host evacuation is triggered whenever the node service is stopped. Node labeling is very important and can cause issues if nodes are mislabled or commands are run on nodes with generalized labels. Exercise caution if master hosts are also labeled with color=blue.

When you are ready to continue with the upgrade process, follow these steps.

  1. Evacuate and delete all blue nodes by following one of the following options:

    1. Option A Manually evacuate then delete the color=blue nodes with the following commands:

      $ oadm manage-node --selector=color=blue --evacuate
      $ oc delete node --selector=color=blue
    2. Option B Filter out the masters before running the delete command:

      1. Verify the list of blue node hosts are as expected by running:

        $ oc get nodes -o go-template='{{ range .items }}{{ if and (eq .metadata.labels.foo "bar") \
            (ne .metadata.labels.type "master") }}{{ .metadata.name }}{{ "\n" }}{{end}}{{ end }}';
      2. After the list is determined to be of the blue nodes, run:

        $ for i in $(oc get nodes -o \
            go-template='{{ range .items }}{{ if and (eq .metadata.labels.color "blue") \
            (ne .metadata.labels.type "master") }}{{ .metadata.name }}{{ "\n" }}{{end}}{{ end }}'); \
        do
            oc delete node $i
        done
  2. After the blue node hosts no longer contain pods and have been removed from OpenShift Container Platform they are safe to power off. As a safety precaution, leaving the hosts around for a short period of time can prove beneficial if the upgrade has issues.
  3. Ensure that any desired scripts or files are captured before terminating these hosts. After a determined time period and capacity is not an issue, remove these hosts.

5.5. Operating System Updates and Upgrades

5.5.1. Updating and Upgrading the Operating System

Updating or upgrading your operating system (OS), by either changing OS versions or updating the system software, can impact the OpenShift Container Platform software running on those machines. In particular, these updates can affect the iptables rules or ovs flows that OpenShift Container Platform requires to operate.

Use the following to safely upgrade the OS on a host:

  1. Ensure the host is unschedulable, meaning that no new pods will be placed onto the host:

    $ oadm manage-node <node_name> --schedulable=false
  2. Migrate the pods from the host:

    $ oadm drain <node_name> --force --delete-local-data --ignore-daemonsets
  3. Update or upgrade the host packages, and reboot the host. A reboot ensures that the host is running the newest versions, and means that the docker and OpenShift Container Platform processes have been restarted, which will force them to check that all of the rules in other services are correct.

    However, instead of rebooting a node host, you can restart the services that are affected, or preserve the iptables state. Both processes are described in the OpenShift Container Platform IPtables topic. The ovs flow rules do not need to be saved, but restarting the OpenShift Container Platform node software will fix the flow rules.

  4. Configure the host to be schedulable again:

    $ oadm manage-node <node_name> --schedulable=true

5.6. Migrating Embedded etcd to External etcd

5.6.1. Overview

Until OpenShift Container Platform 3.6, it was possible to deploy a cluster with an embedded etcd. As of OpenShift Container Platform 3.7, this is no longer possible. Additionally, the etcd API version since OpenShift Container Platform 3.6 defaults to v3. Also, since OpenShift Container Platform 3.7, the v3 is the only version allowed. Therefore, older deployments with embedded etcd with the etcd API version v2 need to migrate to the external etcd first, followed by data migration, before they can be upgraded to OpenShift Container Platform 3.7.

This migration process performs the following steps:

  1. Stop the master service.
  2. Perform an etcd backup of embedded etcd.
  3. Deploy external etcd (on the master or new host).
  4. Perform a backup of the original etcd master certificates.
  5. Generate new etcd certificates for the master.
  6. Transfer the embedded etcd backup to the external etcd host.
  7. Start the external etcd from the transfered etcd backup.
  8. Re-configure master to use the external etcd.
  9. Start master.

5.6.2. Running the Automated Migration Playbook

Migration to external RPM etcd or external containerized etcd is currently supported.

A migration playbook is provided to automate all aspects of the process; this is the preferred method for performing the migration. You must have access to your existing inventory file with both the master and external etcd host defined in their separate groups.

In order to perform the migration on Red Hat Enterprise Linux Atomic Host, you must be running Atomic Host 7.4 or later.

  1. Pull the latest subscription data from RHSM:

    # subscription-manager refresh
  2. To get the latest playbooks, manually disable the OpenShift Container Platform 3.6 channel and enable the 3.7 channel on the host you are running the migration from:

    # subscription-manager repos --disable="rhel-7-server-ose-3.6-rpms" \
        --enable="rhel-7-server-ose-3.7-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-fast-datapath-rpms"
    # yum clean all
  3. Add etcd under the [OSEv3:children] section if it does not already exist:

    [OSEv3:children]
    masters
    nodes
    etcd
  4. Your inventory file is expected to have exactly one host in an [etcd] host group. In most scenarios, it is best to use your existing master, as there is no need for a separate host.

    Add an [etcd] host group to your inventory file if it does not already exist, and list the host to migrate your etcd to:

    [etcd]
    master1.example.com
  5. Run the embedded2external.yml playbook using your inventory file:

    # ansible-playbook [-i /path/to/inventory] \
        /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-etcd/embedded2external.yml

    Successful completion of the playbook will show the following:

    INSTALLER STATUS **************************************
    Initialization             : Complete
    etcd Install               : Complete
  6. To verify that the migration from embedded to external etcd was successful, run the following on the etcd host and check for an etcd process:

    # ps -aux | grep etcd
    etcd      22384  2.1  3.9 5872848 306072 ?      Ssl  10:36   0:02 /usr/bin/etcd --name=master1.example.com --data-dir=/var/lib/etcd/ --listen-client-urls=https://192.168.122.197:2379

5.6.3. Running the Manual Migration

Currently, manual migration is not recommended, as it requires a deployment of the new etcd cluster and re-deployment of etcd master certificates.

5.7. Migrating etcd Data (v2 to v3)

5.7.1. Overview

While etcd was updated from etcd v2 to v3 in a previous release, OpenShift Container Platform continued using an etcd v2 data model and API for both new and upgraded clusters. Starting with OpenShift Container Platform 3.6, new installations began using the v3 data model as well, providing improved performance and scalability.

For existing clusters that upgraded to OpenShift Container Platform 3.6, however, the etcd data must be migrated from v2 to v3 as a post-upgrade step. This must be performed using openshift-ansible version 3.6.173.0.21 or later.

Until OpenShift Container Platform 3.6, it was possible to deploy a cluster with an embedded etcd. As of OpenShift Container Platform 3.7, this is no longer possible. See Migrating Embedded etcd to External etcd.

The etcd v2 to v3 data migration is performed as an offline migration which means all etcd members and master services are stopped during the migration. Large clusters with up to 600MiB of etcd data can expect a 10 to 15 minute outage of the API, web console, and controllers.

This migration process performs the following steps:

  1. Stop the master API and controller services.
  2. Perform an etcd backup on all etcd members.
  3. Perform a migration on the first etcd host
  4. Remove etcd data from any remaining etcd hosts.
  5. Perform an etcd scaleup operation adding additional etcd hosts one by one.
  6. Re-introduce TTL information on specific keys.
  7. Reconfigure the masters for etcd v3 storage.
  8. Start the master API and controller services.

5.7.2. Before You Begin

You can only begin the etcd data migration process after upgrading to OpenShift Container Platform 3.6, as previous versions are not compatible with etcd v3 storage. Additionally, the upgrade to OpenShift Container Platform 3.6 reconfigures cluster DNS services to run on every node, rather than on the masters, which ensures that, even when master services are taken down, existing pods continue to function as expected.

Older deployments with embedded etcd with the etcd API version v2 need to migrate to the external etcd before migrating data. See Migrating Embedded etcd to External etcd.

5.7.3. Running the Automated Migration Playbook

A migration playbook is provided to automate all aspects of the process; this is the preferred method for performing the migration. You must have access to your existing inventory file with both masters and etcd hosts defined in their separate groups.

  1. Pull the latest subscription data from RHSM:

    # subscription-manager refresh
  2. To get the latest playbooks, manually disable the OpenShift Container Platform 3.6 channel and enable the 3.7 channel on the host you are running the migration from:

    # subscription-manager repos --disable="rhel-7-server-ose-3.6-rpms" \
        --enable="rhel-7-server-ose-3.7-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-fast-datapath-rpms"
    # yum clean all
  3. Run the migrate.yml playbook using your inventory file:

    # ansible-playbook [-i /path/to/inventory] \
        /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-etcd/migrate.yml

5.7.4. Running the Migration Manually

The following procedure describes the steps required to successfully migrate the cluster (implemented as part of the Ansible etcd migration playbook).

  1. <b>Create an etcd backup.</b> See Backup and Restore for steps.
  2. <b>Stop masters and wait for etcd convergence:</b>

    1. Stop all master services:

      # systemctl stop atomic-openshift-master \
          atomic-openshift-master-api \
          atomic-openshift-master-controllers
    2. Before the migration can proceed, the etcd cluster must be healthy and raft indices of all etcd members must differ by one unit at most. At the same time, all etcd members and master daemons must be stopped.

      To check the etcd cluster is healthy you can run:

      # etcdctl <certificate_details> <endpoint> cluster-health 1
      member 2a3d833935d9d076 is healthy: got healthy result from https://etcd-test-1:2379
      member a83a3258059fee18 is healthy: got healthy result from https://etcd-test-2:2379
      member 22a9f2ddf18fee5f is healthy: got healthy result from https://etcd-test-3:2379
      cluster is healthy
      1
      For <certificate_details>, see Backup and Restore for an example of how to set certificate flags.

      To check a difference of raft indices you can run:

      # ETCDCTL_API=3 etcdctl <certificate_details> <endpoint> -w table endpoint status
      +------------------+------------------+---------+---------+-----------+-----------+------------+
      |     ENDPOINT     |        ID        | VERSION | DB SIZE | IS LEADER | RAFT TERM | RAFT INDEX |
      +------------------+------------------+---------+---------+-----------+-----------+------------+
      | etcd-test-1:2379 | 2a3d833935d9d076 | 3.1.9   | 25 kB   | false     |       415 |        995 |
      | etcd-test-2:2379 | a83a3258059fee18 | 3.1.9   | 25 kB   | true      |       415 |        995 |
      | etcd-test-3:2379 | 22a9f2ddf18fee5f | 3.1.9   | 25 kB   | false     |       415 |        995 |
      +------------------+------------------+---------+---------+-----------+-----------+------------+

      If the minimum and maximum of raft indexes over all etcd members differ by more than one unit, wait a minute and try the command again.

  3. <b>Migrate and scale up etcd:</b>

    Warning

    The migration should not be run repeatedly, as new v2 data can overwrite v3 data that has already migrated.

    1. Stop etcd on all etcd hosts:

      # systemctl stop etcd
    2. Run the following command (with the etcd daemon stopped) on your first etcd host to perform the migration:

      # ETCDCTL_API=3 etcdctl migrate --data-dir=/var/lib/etcd

      The --data-dir target can in a different location depending on the deployment. For example, embedded etcd operates over the /var/lib/origin/openshift.local.etcd directory, and etcd run as a system container operates over the /var/lib/etcd/etcd.etcd directory.

      When complete, the migration responds with the following message if successful:

      finished transforming keys

      If there is no v2 data, it responds with:

      no v2 keys to migrate
    3. On each remaining etcd host, move the existing member directory to a backup location:

      $ mv /var/lib/etcd/member /var/lib/etc/member.old
    4. Create a new cluster on the first host:

      # echo "ETCD_FORCE_NEW_CLUSTER=true" >> /etc/etcd/etcd.conf
      # systemctl start etcd
      # sed -i '/ETCD_FORCE_NEW_CLUSTER=true/d' /etc/etcd/etcd.conf
      # systemctl restart etcd
    5. Scale up additional etcd hosts by following the Adding Additional etcd Members documentation.
    6. When the etcdctl migrate command is run without the --no-ttl option, TTL keys are migrated as well. Given that the TTL keys in v2 data are replaced with leases in v3 data, you must attach leases to all migrated TTL keys (with the etcd daemon running).

      After your etcd cluster is back online with all members, re-introduce the TTL information by running the following on the first master:

      $ oadm migrate etcd-ttl --etcd-address=https://<ip_address>:2379 \
          --cacert=/etc/origin/master/master.etcd-ca.crt \
          --cert=/etc/origin/master/master.etcd-client.crt \
          --key=/etc/origin/master/master.etcd-client.key \
          --ttl-keys-prefix '/kubernetes.io/events' \
          --lease-duration 1h
      $ oadm migrate etcd-ttl --etcd-address=https://<ip_address>:2379 \
          --cacert=/etc/origin/master/master.etcd-ca.crt \
          --cert=/etc/origin/master/master.etcd-client.crt \
          --key=/etc/origin/master/master.etcd-client.key \
          --ttl-keys-prefix '/kubernetes.io/masterleases' \
          --lease-duration 10s
      $ oadm migrate etcd-ttl --etcd-address=https://<ip_address>:2379 \
          --cacert=/etc/origin/master/master.etcd-ca.crt \
          --cert=/etc/origin/master/master.etcd-client.crt \
          --key=/etc/origin/master/master.etcd-client.key \
          --ttl-keys-prefix '/openshift.io/oauth/accesstokens' \
          --lease-duration 86400s
      $ oadm migrate etcd-ttl --etcd-address=https://<ip_address>:2379 \
          --cacert=/etc/origin/master/master.etcd-ca.crt \
          --cert=/etc/origin/master/master.etcd-client.crt \
          --key=/etc/origin/master/master.etcd-client.key \
          --ttl-keys-prefix '/openshift.io/oauth/authorizetokens' \
          --lease-duration 500s
      $ oadm migrate etcd-ttl --etcd-address=https://<ip_address>:2379 \
          --cacert=/etc/origin/master/master.etcd-ca.crt \
          --cert=/etc/origin/master/master.etcd-client.crt \
          --key=/etc/origin/master/master.etcd-client.key \
          --ttl-keys-prefix '/openshift.io/leases/controllers' \
          --lease-duration 10s
  4. <b>Reconfigure the master:</b>

    1. After the migration is complete, the master configuration file (the /etc/origin/master/master-config.yaml file by default) must be updated so the master daemons can use the new storage back end:

      kubernetesMasterConfig:
        apiServerArguments:
          storage-backend:
          - etcd3
          storage-media-type:
          - application/vnd.kubernetes.protobuf
    2. Restart your services; for single master clusters, run:

      # systemctl start atomic-openshift-master

      For multiple master clusters, run the following on all masters:

      # systemctl start atomic-openshift-master-api \
          atomic-openshift-master-controllers

5.7.5. Recovering from Migration Issues

If you discover problems after the migration has completed, you may wish to restore from a backup:

  1. Stop the master services:

    # systemctl stop atomic-openshift-master \
        atomic-openshift-master-api \
        atomic-openshift-master-controllers
  2. Remove the storage-backend and storage-media-type keys from from kubernetesMasterConfig.apiServerArguments section in the master configuration file on each master:

    kubernetesMasterConfig:
      apiServerArguments:
       ...
  3. Restore from backups that were taken prior to the migration, located in a timestamped directory under /var/lib/etcd, such as:

    /var/lib/etcd/openshift-backup-pre-migration20170825135732

    Use procedure described in Cluster Restore for Multiple-member etcd Clusters or Cluster Restore for Single-member etcd Clusters.

  4. Restart master services; for single master clusters, run:

    # systemctl start atomic-openshift-master

    For multiple master clusters, run the following on all masters:

    # systemctl start atomic-openshift-master-api \
        atomic-openshift-master-controllers

Chapter 6. Downgrading OpenShift

6.1. Overview

Following an OpenShift Container Platform upgrade, it may be desirable in extreme cases to downgrade your cluster to a previous version. The following sections outline the required steps for each system in a cluster to perform such a downgrade for the OpenShift Container Platform 3.7 to 3.6 downgrade path.

Warning

These steps are currently only supported for RPM-based installations of OpenShift Container Platform and assumes downtime of the entire cluster.

6.2. Verifying Backups

The Ansible playbook used during the upgrade process should have created a backup of the master-config.yaml file and the etcd data directory. Ensure these exist on your masters and etcd members:

/etc/origin/master/master-config.yaml.<timestamp>
/var/lib/etcd/openshift-backup-<timestamp>

Also, back up the node-config.yaml file on each node (including masters, which have the node component on them) with a timestamp:

/etc/origin/node/node-config.yaml.<timestamp>

If you are using an external etcd cluster (versus the single embedded etcd), the backup is likely created on all etcd members, though only one is required for the recovery process.

The RPM downgrade process in a later step should create .rpmsave backups of the following files, but it may be a good idea to keep a separate copy regardless:

/etc/sysconfig/atomic-openshift-master
/etc/etcd/etcd.conf 1
1
Only required if using external etcd.

6.3. Shutting Down the Cluster

On all masters, nodes, and etcd members (if using an external etcd cluster), ensure the relevant services are stopped.

On the master in a single master cluster:

# systemctl stop atomic-openshift-master

On each master in a multi-master cluster:

# systemctl stop atomic-openshift-master-api
# systemctl stop atomic-openshift-master-controllers

On all master and node hosts:

# systemctl stop atomic-openshift-node

On any external etcd hosts:

# systemctl stop etcd

6.4. Removing RPMs

  1. The *-excluder packages add entries to the exclude directive in the host’s /etc/yum.conf file when installed. Run the following command on each host to remove the atomic-openshift-* and docker packages from the exclude list:

    # atomic-openshift-excluder unexclude
    # atomic-openshift-docker-excluder unexclude
  2. On all masters, nodes, and etcd members (if using an external etcd cluster), remove the following packages:

    # yum remove atomic-openshift \
        atomic-openshift-clients \
        atomic-openshift-node \
        atomic-openshift-master \
        openvswitch \
        atomic-openshift-sdn-ovs \
        tuned-profiles-atomic-openshift-node\
        atomic-openshift-excluder\
        atomic-openshift-docker-excluder
  3. If you are using external etcd, also remove the etcd package:

    # yum remove etcd

    If using the embedded etcd, leave the etcd package installed. It is required for running the etcdctl command to issue operations in later steps.

6.5. Downgrading Docker

Both OpenShift Container Platform 3.6 and 3.7 require Docker 1.12, so Docker does not need to be downgraded.

6.6. Reinstalling RPMs

Disable the OpenShift Container Platform 3.7 repositories, and re-enable the 3.6 repositories:

# subscription-manager repos \
    --disable=rhel-7-server-ose-3.7-rpms \
    --enable=rhel-7-server-ose-3.6-rpms

On each master, install the following packages:

# yum install atomic-openshift \
    atomic-openshift-clients \
    atomic-openshift-node \
    atomic-openshift-master \
    openvswitch \
    atomic-openshift-sdn-ovs \
    tuned-profiles-atomic-openshift-node \
    atomic-openshift-excluder \
    atomic-openshift-docker-excluder

On each node, install the following packages:

# yum install atomic-openshift \
    atomic-openshift-node \
    openvswitch \
    atomic-openshift-sdn-ovs \
    tuned-profiles-atomic-openshift-node \
    atomic-openshift-excluder \
    atomic-openshift-docker-excluder

If using an external etcd cluster, install the following package on each etcd member:

# yum install etcd

6.7. Restoring etcd

See Backup and Restore.

6.8. Bringing OpenShift Container Platform Services Back Online

See Backup and Restore.

6.9. Verifying the Downgrade

  1. To verify the downgrade, first check that all nodes are marked as Ready:

    # oc get nodes
    NAME                        STATUS                     AGE
    master.example.com          Ready,SchedulingDisabled   165d
    node1.example.com           Ready                      165d
    node2.example.com           Ready                      165d
  2. Then, verify that you are running the expected versions of the docker-registry and router images, if deployed:

    # oc get -n default dc/docker-registry -o json | grep \"image\"
        "image": "openshift3/ose-docker-registry:v3.6.173.0.49",
    # oc get -n default dc/router -o json | grep \"image\"
        "image": "openshift3/ose-haproxy-router:v3.6.173.0.49",
  3. You can use the diagnostics tool on the master to look for common issues and provide suggestions:

    # oc adm diagnostics
    ...
    [Note] Summary of diagnostics execution:
    [Note] Completed with no errors or warnings seen.

Chapter 7. Master and Node Configuration

7.1. Overview

The openshift start command is used to launch OpenShift Container Platform servers. The command and its subcommands (master to launch a master server and node to launch a node server) all take a limited set of arguments that are sufficient for launching servers in a development or experimental environment.

However, these arguments are insufficient to describe and control the full set of configuration and security options that are necessary in a production environment. To provide those options, it is necessary to use the dedicated master and node configuration files.

Master configuration files and node configuration files are fully specified with no default values. Therefore, any empty value indicates that you want to start up with an empty value for that parameter. This makes it easy to reason about exactly what your configuration is, but it also makes it difficult to remember all of the options to specify. To make this easier, the configuration files can be created with the --write-config option and then used with the --config option.

7.2. Master Configuration Files

This section reviews parameters mentioned in the master-config.yaml file.

You can create a new master configuration file to see the valid options for your installed version of OpenShift Container Platform.

Important

Whenever you modify the master-config.yaml file, you must restart the master for the changes to take effect.

7.2.1. Admission Control Configuration

Table 7.1. Admission Control Configuration Parameters

Parameter NameDescription

AdmissionConfig

Contains admission control plug-in configuration.

APIServerArguments

Key-value pairs that will be passed directly to the Kube API server that match the API servers' command line arguments. These are not migrated, but if you reference a value that does not exist the server will not start. These values may override other settings in KubernetesMasterConfig, which may cause invalid configurations.

ControllerArguments

Key-value pairs that will be passed directly to the Kube controller manager that match the controller manager’s command line arguments. These are not migrated, but if you reference a value that does not exist the server will not start. These values may override other settings in KubernetesMasterConfig, which may cause invalid configurations.

DefaultAdmissionConfig

Used to enable or disable various admission plug-ins. When this type is present as the configuration object under pluginConfig and if the admission plug-in supports it, this will cause an off by default admission plug-in to be enabled.

PluginConfig

Allows specifying a configuration file per admission control plug-in.

PluginOrderOverride

A list of admission control plug-in names that will be installed on the master. Order is significant. If empty, a default list of plug-ins is used.

SchedulerArguments

Key-value pairs that will be passed directly to the Kube scheduler that match the scheduler’s command line arguments. These are not migrated, but if you reference a value that does not exist the server will not start. These values may override other settings in KubernetesMasterConfig, which may cause invalid configurations.

7.2.2. Asset Configuration

Table 7.2. Asset Configuration Parameters

Parameter NameDescription

AssetConfig

Holds the necessary configuration options for serving assets.

DisabledFeatures

A list of features that should not be started. You will likely want to set this as null. It is very unlikely that anyone will want to manually disable features and that is not encouraged.

Extensions

Files to serve from the asset server file system under a subcontext.

ExtensionDevelopment

When set to true, tells the asset server to reload extension scripts and stylesheets for every request rather than only at startup. It lets you develop extensions without having to restart the server for every change.

ExtensionProperties

Key- (string) and value- (string) pairs that will be injected into the console under the global variable OPENSHIFT_EXTENSION_PROPERTIES.

ExtensionScripts

File paths on the asset server files to load as scripts when the web console loads.

ExtensionStylesheets

File paths on the asset server files to load as style sheets when the web console loads.

LoggingPublicURL

The public endpoint for logging (optional).

LogoutURL

An optional, absolute URL to redirect web browsers to after logging out of the web console. If not specified, the built-in logout page is shown.

MasterPublicURL

How the web console can access the OpenShift Container Platform server.

MetricsPublicURL

The public endpoint for metrics (optional).

PublicURL

URL of the the asset server.

7.2.3. Authentication and Authorization Configuration

Table 7.3. Authentication and Authorization Parameters

Parameter NameDescription

authConfig

Holds authentication and authorization configuration options.

AuthenticationCacheSize

Indicates how many authentication results should be cached. If 0, the default cache size is used.

AuthorizationCacheTTL

Indicates how long an authorization result should be cached. It takes a valid time duration string (e.g. "5m"). If empty, you get the default timeout. If zero (e.g. "0m"), caching is disabled.

7.2.4. Controller Configuration

Table 7.4. Controller Configuration Parameters

Parameter NameDescription

Controllers

List of the controllers that should be started. If set to none, no controllers will start automatically. The default value is * which will start all controllers. When using *, you may exclude controllers by prepending a - in front of their name. No other values are recognized at this time.

ControllerLeaseTTL

Enables controller election, instructing the master to attempt to acquire a lease before controllers start and renewing it within a number of seconds defined by this value. Setting this value non-negative forces pauseControllers=true. This value defaults off (0, or omitted) and controller election can be disabled with -1.

PauseControllers

Instructs the master to not automatically start controllers, but instead to wait until a notification to the server is received before launching them.

7.2.5. etcd Configuration

Table 7.5. etcd Configuration Parameters

Parameter NameDescription

Address

The advertised host:port for client connections to etcd.

etcdClientInfo

Contains information about how to connect to etcd.

etcdConfig

Holds the necessary configuration options for connecting with an etcd database.

etcdStorageConfig

Contains information about how API resources are stored in etcd. These values are only relevant when etcd is the backing store for the cluster.

KubernetesStoragePrefix

The path within etcd that the Kubernetes resources will be rooted under. This value, if changed, will mean existing objects in etcd will no longer be located. The default value is kubernetes.io.

KubernetesStorageVersion

The API version that Kubernetes resources in etcd should be serialized to. This value should not be advanced until all clients in the cluster that read from etcd have code that allows them to read the new version.

OpenShiftStoragePrefix

The path within etcd that the OpenShift Container Platform resources will be rooted under. This value, if changed, will mean existing objects in etcd will no longer be located. The default value is openshift.io.

OpenShiftStorageVersion

API version that OS resources in etcd should be serialized to. This value should not be advanced until all clients in the cluster that read from etcd have code that allows them to read the new version.

PeerAddress

The advertised host:port for peer connections to etcd.

PeerServingInfo

Describes how to start serving the etcd peer.

ServingInfo

Describes how to start serving the etcd master.

StorageDir

The path to the etcd storage directory.

7.2.6. Grant Configuration

Table 7.6. Grant Configuration Parameters

Parameter NameDescription

GrantConfig

Describes how to handle grants.

GrantHandlerAuto

Auto-approves client authorization grant requests.

GrantHandlerDeny

Auto-denies client authorization grant requests.

GrantHandlerPrompt

Prompts the user to approve new client authorization grant requests.

Method

Determines the default strategy to use when an OAuth client requests a grant.This method will be used only if the specific OAuth client does not provide a strategy of their own. Valid grant handling methods are:

  • auto: always approves grant requests, useful for trusted clients
  • prompt: prompts the end user for approval of grant requests, useful for third-party clients
  • deny: always denies grant requests, useful for black-listed clients

7.2.7. Image Configuration

Table 7.7. Image Configuration Parameters

Parameter NameDescription

Format

The format of the name to be built for the system component.

Latest

Determines if the latest tag will be pulled from the registry.

7.2.8. Image Policy Configuration

Table 7.8. Image Policy Configuration Parameters

Parameter NameDescription

DisableScheduledImport

Allows scheduled background import of images to be disabled.

MaxImagesBulkImportedPerRepository

Controls the number of images that are imported when a user does a bulk import of a Docker repository. This number defaults to 5 to prevent users from importing large numbers of images accidentally. Set -1 for no limit.

MaxScheduledImageImportsPerMinute

The maximum number of scheduled image streams that will be imported in the background per minute. The default value is 60.

ScheduledImageImportMinimumIntervalSeconds

The minimum number of seconds that can elapse between when image streams scheduled for background import are checked against the upstream repository. The default value is 15 minutes.

AllowedRegistriesForImport

Limits the docker registries that normal users may import images from. Set this list to the registries that you trust to contain valid Docker images and that you want applications to be able to import from. Users with permission to create Images or ImageStreamMappings via the API are not affected by this policy - typically only administrators or system integrations will have those permissions.

InternalRegistryHostname

Sets the hostname for the default internal image registry. The value must be in hostname[:port] format. For backward compatibility, users can still use OPENSHIFT_DEFAULT_REGISTRY environment variable but this setting overrides the environment variable.

ExternalRegistryHostname

ExternalRegistryHostname sets the hostname for the default external image registry. The external hostname should be set only when the image registry is exposed externally. The value is used in publicDockerImageRepository field in ImageStreams. The value must be in hostname[:port] format.

7.2.9. Kubernetes Master Configuration

Table 7.9. Kubernetes Master Configuration Parameters

Parameter NameDescription

APILevels

A list of API levels that should be enabled on startup, v1 as examples.

DisabledAPIGroupVersions

A map of groups to the versions (or *) that should be disabled.

KubeletClientInfo

Contains information about how to connect to kubelets.

KubernetesMasterConfig

Holds the necessary configuration options for the Kubernetes master.

MasterCount

The number of expected masters that should be running. This value defaults to 1 and may be set to a positive integer, or if set to -1, indicates this is part of a cluster.

MasterIP

The public IP address of Kubernetes resources. If empty, the first result from net.InterfaceAddrs will be used.

MasterKubeConfig

File name for the .kubeconfig file that describes how to connect this node to the master.

ServicesNodePortRange

The range to use for assigning service public ports on a host. Default 30000-32767.

Servi