Chapter 2. Installing

2.1. Overview

The quick installation method allows you to use an interactive CLI utility to install OpenShift Enterprise across a set of hosts. This installer is a self-contained wrapper intended for usage on a Red Hat Enterprise Linux 7 host.

For production environments, a reference configuration implemented using Ansible playbooks is available as the advanced installation method.

Note

Before beginning either installation method, start with the Prerequisites topic.

2.2. Prerequisites

2.2.1. Overview

OpenShift Enterprise infrastructure components can be installed across multiple hosts. The following sections outline the system requirements and instructions for preparing your environment and hosts before installing OpenShift Enterprise.

2.2.2. Planning

For production environments, several factors that can influence installation must be considered prior to deployment:

  • What is the number of required hosts required to run the cluster?
  • How many pods are required in your cluster?
  • Is high availability required? High availability is recommended for fault tolerance.
  • Which installation type do you want to use: RPM or containerized?

2.2.3. System Requirements

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

Important

OpenShift Enterprise 3.2 requires Docker 1.9.1, and supports Docker 1.10 as of OpenShift Enterprise 3.2.1.

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 7.1 or later with "Minimal" installation option, or RHEL Atomic Host 7.2.4 or later.
  • 2 vCPU.
  • Minimum 8 GB RAM.
  • Minimum 30 GB hard disk space for the file system containing /var/.

Nodes

  • Physical or virtual system, or an instance running on a public or private IaaS.
  • Base OS: RHEL 7.1 or later with "Minimal" installation option, or RHEL Atomic Host 7.2.4 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/.
  • An additional minimum 15 GB unallocated space to be used for Docker’s storage back end; see Configuring Docker Storage below.
Important

OpenShift Enterprise 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.

2.2.3.1. Host Recommendations

The following apply to production environments. Test or sample environments will function with the minimum requirements.

Master Hosts
In a highly available OpenShift Enterprise cluster with external etcd, a master host should have 1 CPU core and 1.5 GB of memory, on top of the defaults in the table above, for each 1000 pods. Therefore, the recommended size of master host in an OpenShift Enterprise cluster of 2000 pods would be 2 CPU cores and 5 GB of RAM, in addition to the minimum requirements for a master host of 2 CPU cores and 8 GB of RAM.

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

Node Hosts
The size of a node host depends on the expected size of its workload. As an OpenShift Enterprise cluster administrator, you will need to calculate the expected workload, then add about 10% for overhead. For production environments, allocate enough resources so that 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

300

Maximum pods per nodes

110

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.

2.2.3.2. Configuring Core Usage

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

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

# export GOMAXPROCS=1

2.2.3.3. Security Warning

OpenShift Enterprise 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 Enterprise uses security context constraints that control the actions that pods can perform and what it has the ability to access.

2.2.4. Environment Requirements

The following must be set up in your environment before OpenShift Enterprise can be installed.

2.2.4.1. DNS

A fully functional DNS environment is a requirement for OpenShift Enterprise to work correctly. Adding entries into the /etc/hosts file is not enough, because that file is not copied into containers running on the platform.

To configure the OpenShift Enterprise DNS environment:

Key components of OpenShift Enterprise run themselves inside of containers. By default, these containers receive their /etc/resolv.conf DNS configuration file from their host. OpenShift Enterprise 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. 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 Enterprise 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

Previously, in OpenShift Enterprise 3.1, a DNS server could not be installed on a master node, because it ran its own internal DNS server. Now, with master nodes using dnsmasq, SkyDNS is now configured to listen on port 8053 so that dnsmasq can run on the masters. Note that these DNS changes (dnsmasq configured on nodes and the SkyDNS port change) only apply to new installations of OpenShift Enterprise 3.2. Clusters upgraded to OpenShift Enterprise 3.2 from a previous version do not currently have these changes applied during the upgrade process.

Note

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

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 Enterprise web console, because it is not accessible via IP address alone

Configuring a DNS Environment

To properly configure your DNS environment for OpenShift Enterprise:

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

    $ cat /etc/resolv.conf
    # Generated by NetworkManager
    search ose3.example.com
    nameserver 10.64.33.1
    # nameserver updated by /etc/NetworkManager/dispatcher.d/99-origin-dns.sh
  2. Ensure that the DNS servers listed in /etc/resolv.conf are able to resolve to the addresses of all the masters and nodes in your OpenShift Enterprise environment:

    $ dig <node_hostname> @<IP_address> +short

    For example:

    $ dig node1.ose3.example.com @10.64.33.1 +short
    10.64.33.156
    $ dig master.ose3.example.com @10.64.33.1 +short
    10.64.33.37
  3. 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 Enterprise (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).

2.2.4.1.1. Disabling dnsmasq

If you want to disable dnsmasq (for example, if your /etc/resolv.conf is managed by a configuration tool other than NetworkManager), then set openshift_use_dnsmasq to false in the Ansible playbook.

However, certain containers do not properly move to the next nameserver when the first issues SERVFAIL. Red Hat Enterprise Linux (RHEL)-based containers do not suffer from this, but certain versions of uclibc and musl do.

Configuring Wildcard DNS

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 Enterprise 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 Enterprise may fail to resolve host names properly.

Running Diagnostics

To explore your DNS setup and run specific DNS queries, you can use the host and dig commands (part of the bind-utils package). For example, you can query a specific DNS server, or check if recursion is involved.

$ host `hostname`
ose3-master.example.com has address 172.16.25.41

$ dig ose3-node1.example.com  +short
172.16.25.45

2.2.4.2. 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.

NetworkManager

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

Required Ports

OpenShift Enterprise infrastructure components communicate with each other using ports, which are communication endpoints that are identifiable for specific processes or services. Ensure the following ports required by OpenShift Enterprise are open between hosts, for example if you have a firewall in your environment. 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 Enterprise SDN). Required only internally on node hosts.

8443

TCP

For use by the OpenShift Enterprise 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 Enterprise 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.

2.2.4.3. Git Access

You must have either Internet access and a GitHub account, or read and write access to an internal, HTTP-based Git server

2.2.4.4. Persistent Storage

The Kubernetes persistent volume framework allows you to provision an OpenShift Enterprise cluster with persistent storage using networked storage available in your environment. This can be done after completing the initial OpenShift Enterprise 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 Enterprise cluster with persistent storage using NFS, GlusterFS, Ceph RBD, OpenStack Cinder, AWS Elastic Block Store (EBS), GCE Persistent Disks, and iSCSI.

2.2.4.5. SELinux

Security-Enhanced Linux (SELinux) must be enabled on all of the servers before installing OpenShift Enterprise 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

2.2.4.6. Cloud Provider Considerations

Set up the 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 Enterprise 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 Enterprise hosts for environments installed prior to or upgraded to 3.2
  • udp/53 from all OpenShift Enterprise hosts for environments installed prior to or upgraded to 3.2
  • tcp/8053 from all OpenShift Enterprise hosts for new environments installed with 3.2
  • udp/8053 from all OpenShift Enterprise 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 Enterprise 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.

Override 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 playbooks/byo/openshift_facts.yml

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.

Post-Installation Configuration for Cloud Providers

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

2.2.5. Host Preparation

Before installing OpenShift Enterprise, you must first prepare each host per the following.

2.2.5.1. Software Prerequisites

Installing an Operating System

A base installation of RHEL 7.1 or later or RHEL Atomic Host 7.2.4 or later is required for master and node hosts. See the following documentation for the respective installation instructions, if required:

Registering the Hosts

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

  1. On each host, register with RHSM:

    # subscription-manager register --username=<user_name> --password=<password>
  2. List the available subscriptions:

    # subscription-manager list --available
  3. In the output for the previous command, find the pool ID for an OpenShift Enterprise subscription and attach it:

    # subscription-manager attach --pool=<pool_id>
    Note

    When finding the pool ID, the related subscription name might include either "OpenShift Enterprise" or "OpenShift Container Platform", due to the product name change introduced with version 3.3.

  4. Disable all repositories and enable only the required ones:

    # subscription-manager repos --disable="*"
    # subscription-manager repos \
        --enable="rhel-7-server-rpms" \
        --enable="rhel-7-server-extras-rpms" \
        --enable="rhel-7-server-ose-3.2-rpms"

Managing 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
  2. Update the system to the latest packages:

    # yum update
  3. Install the following package, which provides OpenShift Enterprise 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
  4. Install the following *-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 Enterprise version:

    # yum install atomic-openshift-excluder atomic-openshift-docker-excluder
  5. 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 packages from the list for the duration of the installation.

    # atomic-openshift-excluder unexclude

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

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 Enterprise.

  1. For RHEL 7 systems, install Docker 1.10.

    Note

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

    The atomic-openshift-docker-excluder package that was installed in Software Prerequisites should ensure that the correct version of Docker is installed in this step:

    # yum install docker

    After the package installation is complete, verify that version 1.10.3 was installed:

    # docker version
  2. Edit the /etc/sysconfig/docker file and add --insecure-registry 172.30.0.0/16 to the OPTIONS parameter. For example:

    OPTIONS='--selinux-enabled --insecure-registry 172.30.0.0/16'

    If using the Quick Installation method, you can easily script a complete installation from a kickstart or cloud-init setup, change the default configuration file:

    # sed -i '/OPTIONS=.*/c\OPTIONS="--selinux-enabled --insecure-registry 172.30.0.0/16"' \
    /etc/sysconfig/docker

    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_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 Enterprise installation is complete, you can choose to secure the integrated Docker registry, which involves adjusting the --insecure-registry option accordingly.

2.2.5.2. Configuring Docker Storage

Docker 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.

  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 Enterprise, 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 Docker 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 Enterprise.

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.

Managing Docker 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.

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

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.

2.2.5.3. 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.

2.2.6. Setting Global Proxy Values

The OpenShift Enterprise installer uses the proxy settings in the _/etc/environment _ file.

Ensure the following domain suffixes and IP addresses are in the /etc/environment file in the no_proxy parameter:

  • Master and node host names (domain suffix).
  • Other internal host names (domain suffix).
  • Etcd IP addresses (must be IP addresses and not host names, as etcd access is done by IP address).
  • Docker registry IP address.
  • Kubernetes IP address, by default 172.30.0.1. Must be the value set in the openshift_portal_net parameter in the Ansible inventory file, by default /etc/ansible/hosts.
  • Kubernetes internal domain suffix: cluster.local.
  • Kubernetes internal domain suffix: .svc.

The following example assumes http_proxy and https_proxy values are set:

no_proxy=.internal.example.com,10.0.0.1,10.0.0.2,10.0.0.3,.cluster.local,.svc,localhost,127.0.0.1,172.30.0.1
Note

Because noproxy does not support CIDR, you can use domain suffixes.

2.2.7. What’s Next?

If you are interested in installing OpenShift Enterprise using the containerized method (optional for RHEL but required for RHEL Atomic Host), see RPM vs Containerized to ensure that you understand the differences between these methods.

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

2.3. RPM vs Containerized

2.3.1. Overview

The default method for installing OpenShift Enterprise on Red Hat Enterprise Linux (RHEL) uses RPMs. Alternatively, you can use the containerized method, which deploys containerized OpenShift Enterprise master and node components. When targeting a RHEL 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.

You can easily deploy environments mixing containerized and RPM based installations. 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 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.

Note

When installing an environment with multiple masters, the load balancer cannot be deployed by the installation process as a container. See Advanced Installation for load balancer requirements using the native HA method.

The following sections detail the differences between the RPM and containerized methods.

2.3.2. 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:

cli_docker_additional_registries=<registry_hostname>
cli_docker_insecure_registries=<registry_hostname>
cli_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.

2.3.3. 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 Enterprise 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.

2.3.4. File Paths

All OpenShift 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.

2.3.5. 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 Enterprise; see the System Requirements section for details.

2.3.6. Open vSwitch SDN Initialization

OpenShift Enterprise 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.

2.4. Quick Installation

2.4.1. Overview

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

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. While RHEL Atomic Host is supported for running containerized OpenShift Enterprise services, the installer is provided by an RPM not available by default 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 Enterprise cluster, but it can be.

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.

2.4.2. Before You Begin

The installer allows you to install OpenShift Enterprise 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 Enterprise 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 Enterprise, 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

If you are interested in installing OpenShift Enterprise using the containerized method (optional for RHEL but required for RHEL Atomic Host), see RPM vs Containerized 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.

2.4.3. 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 Enterprise 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.

2.4.4. 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.

Example 2.1. Installation Configuration File Specification

version: v1 1
variant: openshift-enterprise 2
variant_version: 3.2 3
ansible_ssh_user: root 4
ansible_log_path: /tmp/ansible.log 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
  master: true 11
  node: true 12
  containerized: true 13
  connect_to: 24.222.0.1 14
- ip: 10.0.0.2
  hostname: node1-private.example.com
  public_ip: 24.222.0.2
  public_hostname: node1.example.com
  node: true
  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
  node: true
  connect_to: 10.0.0.3
1
The version of this installation configuration file. As of OpenShift Enterprise 3.1, the only valid version here is v1.
2
The OpenShift Enterprise variant to install. For OSE, set this to openshift-enterprise.
3
A valid version your selected variant: 3.2, 3.1, or 3.0. If not specified, this defaults to the newest version for the specified variant.
4
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.
5
Defines where the Ansible logs are stored. By default, this is the /tmp/ansible.log file.
6
Defines a list of the hosts onto which you want to install the OpenShift Enterprise 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 12
Determines the type of services that are installed. At least one of these must be set to true for the configuration file to be considered valid.
13
If set to true, containerized OpenShift Enterprise 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 RPM vs Containerized for more details.
14
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.

2.4.5. 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.

2.4.6. 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                      LABELS                                                                     STATUS
    master.example.com        kubernetes.io/hostname=master.example.com,region=infra,zone=default        Ready,SchedulingDisabled
    node1.example.com         kubernetes.io/hostname=node1.example.com,region=primary,zone=east          Ready
    node2.example.com         kubernetes.io/hostname=node2.example.com,region=primary,zone=west          Ready
  2. To verify that the web console is installed correctly, use the master host name and the console port number to access the console with a web browser.

    For example, for a master host with a hostname 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. Now that the install has been verified, run the following command on each master and node host to add the atomic-openshift packages back to the list of yum excludes on the host:

    # atomic-openshift-excluder exclude

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

2.4.7. Uninstalling OpenShift Enterprise

You can uninstall OpenShift Enterprise on all hosts in your cluster using the installer by running:

$ atomic-openshift-installer uninstall

See the advanced installation method for more options.

2.4.8. What’s Next?

Now that you have a working OpenShift Enterprise instance, you can:

2.5. Advanced Installation

2.5.1. Overview

For production environments, a reference configuration implemented using Ansible playbooks is available as the advanced installation method for installing OpenShift Enterprise hosts. 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.

While RHEL Atomic Host is supported for running containerized OpenShift Enterprise 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 Enterprise cluster, but it can be.

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

Important

Running Ansible playbooks with the --tags or --check options is not supported by Red Hat.

2.5.2. Before You Begin

Before installing OpenShift Enterprise, you must first see the Prerequisites topic to prepare your hosts, which includes verifying system and environment requirements per component type and properly installing and configuring Docker. It also includes installing Ansible version 2.2.0 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 Enterprise using the containerized method (optional for RHEL but required for RHEL Atomic Host), see RPM vs Containerized 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 in this topic to Configuring Ansible.

2.5.3. Configuring Ansible

The /etc/ansible/hosts file is Ansible’s inventory file for the playbook to use during the installation. The inventory file describes the configuration for your OpenShift Enterprise 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. The examples 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.

2.5.3.1. 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 2.9. 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 Enterprise 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 RPM vs Containerized for more details. Containerized installations are supported starting in OSE 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_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".

2.5.3.2. Configuring Cluster Variables

To assign environment variables during the Ansible install that apply more globally to your OpenShift Enterprise 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 2.10. 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.

containerized

If set to true, containerized OpenShift Enterprise 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 RPM vs Containerized for more details. Containerized installations are supported starting in OSE 3.1.1.

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. If you use an external load balancer, specify the address of the external load balancer.

For example:

---- openshift_master_cluster_public_hostname=openshift-ansible.public.example.com ----

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 Enterprise 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_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 Enterprise 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 172.16.0.0/16, 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.

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.

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 Enterprise 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_docker_additional_registries

OpenShift Enterprise adds the specified additional registry or registries to the Docker configuration.

openshift_docker_insecure_registries

OpenShift Enterprise adds the specified additional insecure registry or registries to the Docker configuration.

openshift_docker_blocked_registries

OpenShift Enterprise adds the specified blocked registry or registries to the Docker configuration.

2.5.3.3. 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 2.11. 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 Enterprise 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.

2.5.3.4. 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 below), 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'}"

The openshift_router_selector and openshift_registry_selector Ansible settings 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 if nodes exist that match the selector settings above. For example:

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

2.5.3.5. Marking Masters as Unschedulable Nodes

Any hosts you designate as masters during the installation process should also be configured as nodes by adding them to the [nodes] section so that the masters are configured as part of the OpenShift Enterprise SDN.

However, in order to ensure that your masters are not burdened with running pods, you can make them unschedulable by adding the openshift_schedulable=false option any node that is also a master. For example:

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

2.5.3.6. 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']

2.5.3.7. Configuring Custom Certificates

Custom serving certificates for the public host names of the OpenShift Enterprise 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"}]

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"]}]

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

2.5.4. Single Master Examples

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

Note

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

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

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

Example 2.2. Single Master and Multiple Nodes 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

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

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

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, 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 Enterprise’s embedded etcd is not supported.

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

Example 2.3. 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
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 openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"

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

2.5.5. 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 following high availability (HA) method:

native

Leverages the native HA master capabilities built into OpenShift Enterprise 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 a load balancing solution of your choice to balance the master API (port 8443) on all master hosts.

For your pre-configured load balancing solution, you must have:

  • A pre-created load balancer VIP configured for SSL passthrough.
  • 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 Enterprise installer.

See External Load Balancer Integrations for more information.

Note

For more on the high availability master architecture, see Kubernetes Infrastructure.

Note the following when using the native HA method:

  • 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.
  • In a HAProxy setup, controller manager servers run as standalone processes. They elect their active leader with a lease stored in etcd. The lease expires after 30 seconds by default. If a failure happens on an active controller server, it will take up to this number of seconds to elect another leader. The interval can be configured with the osm_controller_lease_ttl variable.

To configure multiple masters, refer to the following section.

Multiple Masters with Multiple etcd, and 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 Enterprise’s embedded etcd is not supported.

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

Example 2.4. 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
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

# 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'}"
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"

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, and Using Native HA

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

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

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
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

# override the default controller lease ttl
#osm_controller_lease_ttl=30

# 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 openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"

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

2.5.6. Running the Advanced Installation

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

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

Warning

The installer caches playbook configuration values for 10 minutes, by default. If you change any system, network, or inventory configuration, and then re-run the installer within that 10 minute period, the new values are not used, and the previous values are used instead. You can delete the contents of the cache, which is defined by the fact_caching_connection value in the /etc/ansible/ansible.cfg file.

Note

Due to a known issue, after running the installation, if NFS volumes are provisioned for any component, the following directories might be created whether their components are being deployed to NFS volumes or not:

  • /exports/logging-es
  • /exports/logging-es-ops/
  • /exports/metrics/
  • /exports/prometheus
  • /exports/prometheus-alertbuffer/
  • /exports/prometheus-alertmanager/

You can delete these directories after installation, as needed.

2.5.7. 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                      LABELS                                                                     STATUS
    master.example.com        kubernetes.io/hostname=master.example.com,region=infra,zone=default        Ready,SchedulingDisabled
    node1.example.com         kubernetes.io/hostname=node1.example.com,region=primary,zone=east          Ready
    node2.example.com         kubernetes.io/hostname=node2.example.com,region=primary,zone=west          Ready
  2. To verify that the web console is installed correctly, use the master host name and the console port number to access the console with a web browser.

    For example, for a master host with a hostname 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. Now that the install has been verified, run the following command on each master and node host to add the atomic-openshift packages back to the list of yum excludes on the host:

    # atomic-openshift-excluder exclude

Multiple etcd Hosts

If you installed multiple etcd hosts:

  1. On a etcd 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
  2. 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

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.

2.5.8. Uninstalling OpenShift Enterprise

You can uninstall OpenShift Enterprise hosts in your cluster by running the uninstall.yml playbook. This playbook deletes OpenShift Enterprise 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 Enterprise across all hosts in your cluster, run the playbook using the inventory file you used when installing OpenShift Enterprise initially or ran most recently:

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

2.5.8.1. 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
    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 Enterprise content should be removed from any specified hosts.

2.5.9. Known Issues

The following are known issues for specified installation configurations.

Multiple Masters

  • On failover, 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, run the following on all hosts:

    # yum -y remove openshift openshift-* etcd docker docker-common
    
    # rm -rf /etc/origin /var/lib/openshift /etc/etcd \
        /var/lib/etcd /etc/sysconfig/atomic-openshift* /etc/sysconfig/docker* \
        /root/.kube/config /etc/ansible/facts.d /usr/share/openshift

2.5.10. What’s Next?

Now that you have a working OpenShift Enterprise instance, you can:

2.6. Disconnected Installation

2.6.1. Overview

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

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

  • The OpenShift Enterprise software channels and repositories are not available via Red Hat’s content distribution network.
  • OpenShift Enterprise 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 Enterprise 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 Enterprise, 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 Enterprise nodes. Installing the source control repository is outside the scope of this document.

Also, when building applications in OpenShift Enterprise, 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 Enterprise 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 Enterprise 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 Enterprise 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 Enterprise software onto the Satellite for use with the OpenShift Enterprise 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 Enterprise containerized components. Doing so is outside of the scope of this document.

2.6.2. Prerequisites

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

2.6.3. 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.

2.6.3.1. 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 Enterprise subscriptions:

    # subscription-manager register
  2. Attach to a subscription that provides OpenShift Enterprise channels. You can find the list of available subscriptions using:

    # subscription-manager list --available

    Then, find the pool ID for the subscription that provides OpenShift Enterprise, 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-server-ose-3.2-rpms"
  3. 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.

  4. 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>
  5. 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-server-ose-3.2-rpms
    do
      reposync --gpgcheck -lm --repoid=${repo} --download_path=/path/to/repos
      createrepo -v </path/to/repos/>${repo} -o </path/to/repos/>${repo}
    done

2.6.3.2. Syncing Images

To sync the container images:

  1. Start the Docker daemon:

    # systemctl start docker
  2. Pull all of the required OpenShift Enterprise containerized components:

    # docker pull registry.access.redhat.com/openshift3/ose-haproxy-router:v3.2.1.31
    # docker pull registry.access.redhat.com/openshift3/ose-deployer:v3.2.1.31
    # docker pull registry.access.redhat.com/openshift3/ose-sti-builder:v3.2.1.31
    # docker pull registry.access.redhat.com/openshift3/ose-docker-builder:v3.2.1.31
    # docker pull registry.access.redhat.com/openshift3/ose-pod:v3.2.1.31
    # docker pull registry.access.redhat.com/openshift3/ose-docker-registry:v3.2.1.31
  3. Pull all of the required OpenShift Enterprise containerized components for the additional centralized log aggregation and metrics aggregation components:

    # docker pull registry.access.redhat.com/openshift3/logging-deployment:3.2.1
    # docker pull registry.access.redhat.com/openshift3/logging-elasticsearch:3.2.1
    # docker pull registry.access.redhat.com/openshift3/logging-kibana:3.2.1
    # docker pull registry.access.redhat.com/openshift3/logging-fluentd:3.2.1
    # docker pull registry.access.redhat.com/openshift3/logging-auth-proxy:3.2.1
    # docker pull registry.access.redhat.com/openshift3/metrics-deployer:3.2.1
    # docker pull registry.access.redhat.com/openshift3/metrics-hawkular-metrics:3.2.1
    # docker pull registry.access.redhat.com/openshift3/metrics-cassandra:3.2.1
    # docker pull registry.access.redhat.com/openshift3/metrics-heapster:3.2.1
  4. 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
    • 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

2.6.3.3. 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 Enterprise containerized components:

    # docker save -o ose3-images.tar \
        registry.access.redhat.com/openshift3/ose-haproxy-router \
        registry.access.redhat.com/openshift3/ose-deployer \
        registry.access.redhat.com/openshift3/ose-sti-builder \
        registry.access.redhat.com/openshift3/ose-docker-builder \
        registry.access.redhat.com/openshift3/ose-pod \
        registry.access.redhat.com/openshift3/ose-docker-registry
  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-deployment \
        registry.access.redhat.com/openshift3/logging-elasticsearch \
        registry.access.redhat.com/openshift3/logging-kibana \
        registry.access.redhat.com/openshift3/logging-fluentd \
        registry.access.redhat.com/openshift3/logging-auth-proxy \
        registry.access.redhat.com/openshift3/metrics-deployer \
        registry.access.redhat.com/openshift3/metrics-hawkular-metrics \
        registry.access.redhat.com/openshift3/metrics-cassandra \
        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 Tomcat image:

    # 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

2.6.4. 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.

2.6.4.1. 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

2.6.5. OpenShift Enterprise Systems

2.6.5.1. Building Your Hosts

At this point you can perform the initial creation of the hosts that will be part of the OpenShift Enterprise 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 Enterprise-specific prerequisites.

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

2.6.5.2. Connecting the Repositories

On all of the relevant systems that will need OpenShift Enterprise 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-server-ose-3.2-rpms]
name=rhel-7-server-ose-3.2-rpms
baseurl=http://<server_IP>/repos/rhel-7-server-ose-3.2-rpms
enabled=1
gpgcheck=0

2.6.5.3. Host Preparation

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

Skip the section titled Registering the Hosts and start with Managing Packages.

2.6.6. Installing OpenShift Enterprise

2.6.6.1. Importing OpenShift Enterprise Containerized Components

To import the relevant components, securely copy the images from the connected host to the individual OpenShift Enterprise 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 Enterprise 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 Enterprise 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"

2.6.6.2. Running the OpenShift Enterprise Installer

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

2.6.6.3. Creating the Internal Docker Registry

You now need to create the internal Docker registry.

2.6.7. Post-Installation Changes

In one of the previous steps, the S2I images were imported into the Docker daemon running on one of the OpenShift Enterprise 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 Enterprise 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).

2.6.7.1. 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 Enterprise 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

2.6.7.2. Creating an Administrative User

Pushing the container images into OpenShift Enterprise’s Docker registry requires a user with cluster-admin privileges. Because the default OpenShift Enterprise 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 Enterprise. 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 Enterprise before an account is created in the internal database. Log in to OpenShift Enterprise for this account to be created. This assumes you are using the self-signed certificates generated by OpenShift Enterprise 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

2.6.7.3. Modifying the Security Policies

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

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

2.6.7.4. 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 Enterprise’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

2.6.7.5. 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
    ...

2.6.8. Installing a Router

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

2.7. Configure or Deploy a Docker Registry

2.7.1. Overview

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

2.7.2. Deploying the Registry

Starting in OpenShift Enterprise 3.2, quick installations automatically handle the initial deployment of the Docker registry and the OpenShift Enterprise router. However, you may need to manually create the registry if:

  • You did an advanced install and did not include the openshift_registry_selector variable.

    Or,

  • For some reason it was not automatically deployed during a quick installation.

    Or,

  • You deleted the registry and need to deploy it again.

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
    --selector='region=infra' 4

During advanced installation, the openshift_registry_selector and openshift_hosted_router_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. <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 Enterprise. <4> Optionally, you can specify the node location where you want to install the registry by specifying the corresponding node label.

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.

Use --selector to deploy the registry to any node(s) that match a specified node label:

$ oadm registry <registry_name> --replicas=<number> --selector=<label> \
    --service-account=registry

For example, if you want to create a registry named registry and have it placed on a node labeled with region=infra:

$ oadm registry registry --replicas=1 --selector='region=infra' \
  --service-account=registry

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

$ oadm registry --help

2.7.2.1. 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.

2.7.2.2. Storage for the Registry

The registry stores Docker 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.

2.7.2.2.1. 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

Or, to attach an existing NFS volume to the registry:

$ oc volume deploymentconfigs/docker-registry \
     --add --overwrite --name=registry-storage --mount-path=/registry \
     --source='{"nfs": { "server": "<fqdn>", "path": "/path/to/export"}}'
Note

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

2.7.2.2.1.1. 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
    secretkey: awssecretkey
    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

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.

2.7.2.2.2. 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>

2.7.2.3. Maintaining the Registry IP Address

OpenShift Enterprise 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.

2.7.3. Viewing Logs

To view the logs for the Docker registry, use the oc logs command with the deployment config:

$ 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

2.7.4. File Storage

Tag and image metadata is stored in OpenShift Enterprise, 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 on the node host and identify the container ID for the Docker registry:

    # docker ps | grep ose-docker-registry
  4. List the registry contents using the docker exec command:

    # docker exec -it 4c01db0b339c 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 1
    This directory stores all layers and signatures as blobs.
    2 2
    This file contains the blob’s contents.
    3 3
    This directory stores all the image repositories.
    4 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.

2.7.5. 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.

2.7.5.1. 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.

2.7.5.2. 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 Enterprise as a regular user:

    $ oc login
  2. Get your access token:

    $ oc whoami -t
  3. Log in to the Docker registry:

    $ docker login -u <username> -e <any_email_address> \
        -p <token_value> <registry_ip>:<port>

2.7.5.3. 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 Enterprise 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

2.7.6. Securing the Registry

Optionally, you can secure the registry so that it serves 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
  4. Create the secret for the registry certificates:

    $ oc secrets new registry-secret \
        /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 add serviceaccounts/registry secrets/registry-secret
    $ oc secrets add serviceaccounts/default  secrets/registry-secret
  6. Add the secret volume to the registry deployment configuration:

    $ oc volume dc/docker-registry --add --type=secret \
        --secret-name=registry-secret -m /etc/secrets
  7. Enable TLS by adding the following environment variables to the registry deployment configuration:

    $ oc 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.

  8. 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"}}
      }]}}}}'
  9. If your registry was initially deployed on OpenShift Enterprise 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"}}
      }]}}}}'
  10. 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
  11. 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.
  12. 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
  13. 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

2.7.7. Advanced: 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. However, the middleware section may not be overridden using environment variables. Learn how to override specific configuration options.

2.7.7.1. Deploying Updated Configuration

To enable managing the registry configuration file directly, it is recommended that the configuration file be mounted as a secret volume:

  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:
      repository:
        - name: openshift
          options:
            pullthrough: true

  3. Create a new secret called registry-config from your custom registry configuration file you edited locally:

    $ oc secrets new registry-config config.yml=</path/to/custom/registry/config.yml>
  4. Add the registry-config secret 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=secret \
        --secret-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 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 deploy docker-registry --latest
Tip

Maintain configuration files in a source control repository.

2.7.7.2. 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.

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.

2.7.7.2.1. Log

Upstream options are supported.

log:
  level: debug
  formatter: text
  fields:
    service: registry
    environment: staging
2.7.7.2.2. Hooks

Mail hooks are not supported.

2.7.7.2.3. Storage

The following storage drivers are supported:

General registry storage configuration options are supported.

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.
2.7.7.2.4. Auth

Auth options should not be altered. The openshift extension is the only supported option.

auth:
  openshift:
    realm: openshift
2.7.7.2.5. Middleware

The repository middleware extension allows to configure OpenShift Enterprise middleware responsible for interaction with OpenShift Enterprise and image proxying.

The repository middleware extension should not be altered except for the options section to disable pull-through cache.

middleware:
  repository:
    - name: openshift 1
      options:
        pullthrough: true 2
1
These entries are mandatory. Their presence ensures required components get loaded. These values shouldn’t be changed.
2
Let the registry act as a proxy for remote blobs. See below for more details.
2.7.7.2.6. 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.
2.7.7.2.7. 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: false 1
        enforcequota: false 2
        projectcachettl: 1m 3
        blobrepositorycachettl: 10m 4
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.
2
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. It overrides OpenShift Enterprise middleware configuration option. Recognized values are true and false.
3
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.
4
A configuration option that can be overriden 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.
2.7.7.2.7.1. 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. The blob, served this way, will not be stored in the registry.

This feature is on by default. However, it can be disabled using a configuration option.

2.7.7.2.7.2. Manifest schema v2 support

Each image has a manifest describing its blobs, instructions for running it and additional metadata. The manifest is versioned which have 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). The manifest v2 schema 2 (schema2) is not yet supported.

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, they will push the latter to the registry if it supports newer schema. Which means only schema1 will be pushed to the internal Docker registry.
2.7.7.2.8. Reporting

Reporting is unsupported.

2.7.7.2.9. 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
2.7.7.2.10. 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
2.7.7.2.11. Redis

Redis is not supported.

2.7.7.2.12. Health

Upstream options are supported. The registry deployment configuration provides an integrated health check at /healthz.

2.7.7.2.13. Proxy

Proxy configuration should not be enabled. This functionality is provided by the OpenShift Enterprise repository middleware extension, pullthrough: true.

2.7.8. 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 Enterprise 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 Enterprise, 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.

2.7.9. Exposing the Registry

To expose your internal registry externally, it is recommended that you run a secure registry. To expose the registry you must first have deployed a router.

  1. Deploy the registry.
  2. Secure the registry.
  3. Deploy a router.
  4. Create a passthrough 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.

    For example:

    $ 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
    
    $ oc create route passthrough    \
        --service=docker-registry    \1
        --hostname=<host>
    route "docker-registry" created     2
    1
    Specify the registry as the route’s service.
    2
    The route name is identical to the service name.
    $ 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
    Specify this route as a passthrough route.
    Note

    Passthrough is currently the only type of route supported for exposing the secure registry.

  5. 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
  6. 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. You should now be able to tag and push images using the route host.

    $ 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.

    Note

    In the <host>/test/busybox example above, test refers to the project name.

2.7.10. Known Issues

The following are the known issues when deploying or using the integrated registry.

2.7.10.1. 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 Enterprise versions. If not, change it:

    $ oc get -o yaml svc/docker-registry | \
          sed 's/\(sessionAffinity:\s*\).*/\1ClientIP/' | \
          oc replace -f -
  2. Ensure that the NFS export line of your registry volume on your NFS server has the no_wdelay options listed. See Export Settings in the Persistent Storage Using NFS topic for details.

2.7.10.2. 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.

2.7.10.3. 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.

2.7.10.4. Build Fails with error: build error: Failed to push image: EOF

Check your registry log. If you see similar error message to the one below:

time="2016-08-10T07:29:06.882023903Z" level=panic msg="Configuration error: OpenShift registry middleware not activated" 2016-08-10 07:29:06.882174 I | http: panic serving 10.131.0.1:34558: &{0xc820010680 map[] 2016-08-10 07:29:06.882023903 +0000 UTC panic Configuration error: OpenShift registry middleware not activated}

It means that your custom configuration file lacks mandatory entries in the middleware section. Add them, re-deploy the registry, and restart your builds.

2.7.10.5. 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.

2.7.11. What’s Next?

After you have a registry deployed, you can:

2.8. Configure or Deploy the Router

2.8.1. Overview

The OpenShift Enterprise router is the ingress point for all external traffic destined for services in your OpenShift installation. OpenShift provides and supports the following two 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 Enterprise. 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 Enterprise 3.0.2.

2.8.2. Router Service Account

Before deploying an OpenShift Enterprise cluster, you must have a service account for the router. Starting in OpenShift Enterprise 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.

Use of labels (e.g., to define router shards) requires cluster-reader permission.

$ oadm policy add-cluster-role-to-user \
    cluster-reader \
    system:serviceaccount:default:router

2.8.3. Deploying the Default HAProxy Router

The oadm 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 oadm router command creates the service and deployment configuration objects. Just about every form of communication between OpenShift Enterprise components is secured by TLS and uses various certificates and authentication methods. Use the --credentials option to specify what credentials the router should use to contact the master.

Important

Routers directly attach to port 80 and 443 on all interfaces on a host. Restrict routers to hosts where port 80/443 is 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 credentials with your router. The credentials can be provided using the --credentials flag to the oadm router command. Alternatively, the default cluster administrator credentials can be used from the $KUBECONFIG environment variable.

$ oadm router --dry-run --service-account=router \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' 1
1
--credentials is the path to the CLI configuration file for the openshift-router.
Important

Router pods created using oadm 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.

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:
$ oadm router --dry-run \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --service-account=router
Viewing the Default Router
To see what the default router would look like if created:
$ oadm router -o yaml \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --service-account=router
Creating a Router
The quick installation process automatically creates a default router. To create a router if it does not exist:
$ oadm router <router_name> --replicas=<number> \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --service-account=router
Deploying the Router to a Labeled Node
To deploy the router to any node(s) that match a specified node label:
$ oadm router <router_name> --replicas=<number> --selector=<label> \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --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:

$ oadm router router --replicas=1 --selector='region=infra' \
  --credentials='/etc/origin/master/openshift-router.kubeconfig' \
  --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.

To deploy the router to any node(s) that match a specified node label:

$ oadm 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:

$ oadm router router --replicas=1 --selector='region=infra' \
  --service-account=router
Using a Different Router Image
To use a different router image and view the router configuration that would be used:
$ oadm router <router_name> -o <format> --images=<image> \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --service-account=router

For example:

$ oadm router region-west -o yaml --images=myrepo/somerouter:mytag \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --service-account=router

2.8.3.1. High Availability

You can set up a highly-available router on your OpenShift Enterprise cluster using IP failover.

2.8.3.2. 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).

$ oadm 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

2.8.3.3. Working With Multiple Routers

An administrator can create multiple routers with the same definition to serve the same set of routes. By having different groups of routers with different namespace or route selectors, they can vary the routes that the router serves.

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 handles 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.

2.8.3.4. 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.

2.8.3.5. Using Router Shards

The access controls are based on the service account that the router is run with.

Using NAMESPACE_LABELS and/or ROUTE_LABELS, a router can filter out the namespaces and/or routes that it should service. This enables you to partition routes amongst multiple router deployments effectively distributing the set of routes.

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 3 namespaces finance, ops or dev, then this could effectively distribute our 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 accross multiple router deployments.

Example: In addition to the finops-router and dev-router in the example above, we also have an 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 where we have partitioned the routes with an overlapping set.

In addition, this enables us to create more complex routing rules ala divert high priority traffic to the dedicated finops-router but send the lower priority ones to the devops-router.

NAMESPACE_LABELS allows filtering the projects to service and selecting all the routes from those projects. But we 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)"

Example assumes you have all the routes you wish to serviced tagged with a label "mydeployment=<tag>".

2.8.3.6. Creating Router Shards

Router sharding lets you select how routes are distributed among a set of routers.

Router sharding is based on labels; you set labels on the routes in the pool, and express the desired subset of those routes for the router to serve 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 oadm 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
oadm 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

2.8.3.7. 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-dhsard-<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'

2.8.3.8. 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:

$ oadm 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

2.8.4. 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:

# oadm router myrouter --router-canonical-hostname="rtr.example.com"

This creates the ROUTER_CANONCAL_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_CANONCAL_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_CANONCAL_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.

2.8.4.1. Customizing the Default Routing Subdomain

You can customize the default routing subdomain by modifying the master configuration file. Routes that do not specify a host name would have one generated using this default routing subdomain.

2.8.4.1.1. Modifying the Master Configuration file

You can customize the suffix used as the default routing subdomain for your environment using the master configuration file (the /etc/origin/master/master-config.yaml file by default).

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 Enterprise 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

2.8.4.2. 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 oadm 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.

$ oadm router --force-subdomain='${name}-${namespace}.apps.example.com'

2.8.4.3. 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 Enterprise CA to create the certificate. For example:

$ CA=/etc/origin/master
$ oadm 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

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:

$ oadm router --default-cert=cloudapps.router.pem --service-account=router \
    --credentials=${ROUTER_KUBECONFIG:-"$KUBECONFIG"}
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.

2.8.4.4. 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:

# oadm router --replicas=1 --service-account=router  \
    --credentials=${ROUTER_KUBECONFIG:-"$KUBECONFIG"}

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/

2.8.4.5. Using the Container Network Stack

The OpenShift Enterprise 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:

$ oadm router \
    --credentials='/etc/origin/master/openshift-router.kubeconfig' \
    --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 Enterprise 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.

2.8.4.6. Exposing Router metrics

Using the --metrics-image and --expose-metrics options, you can configure the OpenShift Enterprise 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 Enterprise router:

    $ oadm router \
        --credentials='/etc/origin/master/openshift-router.kubeconfig' \
        --service-account=router --expose-metrics

    Or, optionally, use the --metrics-image option to override the HAProxy defaults:

    $ oadm router \
        --credentials='/etc/origin/master/openshift-router.kubeconfig' \
        --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 "

2.8.4.7. 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:

$ oadm 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 root:

$ oc patch dc router -p '{"spec":{"template":{"spec":{"containers":[{"name":"router","securityContext":{"privileged":true}}]}}}}'

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=1

If you used a non-default name for the router, you must change dc/router accordingly.

2.8.5. Deploying a Customized HAProxy Router

The HAProxy router is based on a golang template that generates the HAProxy configuration file from a list of routes. If you want a customized template router to meet your needs, you can customize the template file, build a new Docker image, and run a customized router. Alternatively you can use a ConfigMap.

One common case for this might be implementing new features within the application back ends. For example, it might be desirable in a highly-available setup to use stick-tables that synchronizes between peers. The router plug-in provides all the facilities necessary to make this customization.

You can obtain a new haproxy-config.template file from the latest router image by running:

# docker run --rm --interactive=true --tty --entrypoint=cat \
    registry.access.redhat.com/openshift3/ose-haproxy-router:v3.0.2.0 haproxy-config.template

Save this content to a file for use as the basis of your customized template.

2.8.5.1. Using a ConfigMap to Replace the Router Configuration Template

You can use 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 env and oc volume commands, or alternatively by editing the router deployment configuration.

    Using oc commands
    $ oc env dc/router \
        TEMPLATE_FILE=/var/lib/haproxy/conf/custom/haproxy-config.template
    $ oc volume dc/router --add --overwrite \
        --name=config-volume \
        --mount-path=/var/lib/haproxy/conf/custom \
        --source='{"configMap": { "name": "customrouter"}}'
    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.

2.8.5.2. 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.

2.8.5.3. Rebuilding Your Router

After you have made any desired modifications to the template, such as the example stick tables customization, you must rebuild your router for your changes to go in effect:

  1. Rebuild the Docker image to include your customized template.
  2. Push the resulting image to your repository.
  3. Create the router specifying your new image, either:

    1. in the pod’s object definition directly, or
    2. by adding the --images=<repo>/<image>:<tag> flag to the oadm router command when creating a highly-available routing service.

2.8.6. Deploying the F5 Router

Note

The F5 router plug-in is available starting in OpenShift Enterprise 3.0.2.

The F5 router plug-in is provided as a Docker image and run as a pod, just like the default HAProxy router. Deploying the F5 router is done similarly as well, using the oadm router command but providing additional flags (or environment variables) to specify 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.

--external-host-https-vserver

Specifies the name of the F5 virtual server for HTTPS connections.

--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.

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 only watching routes and endpoints 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.

The F5 router will also need to be run in privileged mode because route certificates get copied using scp:

$ oadm policy remove-scc-from-user hostnetwork -z router
$ oadm policy add-scc-to-user privileged -z router

To deploy the F5 router:

  1. First, establish a tunnel using a ramp node, which allows for the routing of traffic to pods through the OpenShift Enterprise SDN.
  2. Run the oadm router command with the appropriate flags. 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 \
        --credentials='/etc/origin/master/openshift-router.kubeconfig' \1
        --service-account=router
    1
    --credentials is the path to the CLI configuration file for the openshift-router. It is recommended using an openshift-router specific profile with appropriate permissions.

2.8.7. What’s Next?

If you deployed an HAProxy router, you can learn more about monitoring the router.

If you have not yet done so, you can: