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Language:
English
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Language:
English
Getting Started Guide
Quick-start guide to using and developing with CodeReady Containers
Kevin Owen
kowen@redhat.com
devtools-docs@redhat.com
Abstract
Chapter 1. Getting started with Red Hat CodeReady Containers
1.1. Understanding CodeReady Containers
Red Hat CodeReady Containers brings a minimal OpenShift 4 cluster to your local computer. This cluster provides a minimal environment for development and testing purposes. It’s mainly targetted at running on developers' desktops. For other use cases, such as headless, multi-developer/team-based setups, …, use of the full-fledged OpenShift installer is recommended.
You can refer to the OpenShift documentation for a more in-depth introduction to OpenShift.
CodeReady Containers includes the crc
command-line interface (CLI) to interact with the CodeReady Containers virtual machine running the OpenShift cluster.
1.2. Differences with a production OpenShift install
Red Hat CodeReady Containers is a regular OpenShift installation with the following notable differences:
- It uses a single node which behaves both as a master and as a worker node.
-
The
machine-config
andmonitoring
Operators are disabled by default. - These disabled Operators will cause the corresponding parts of the web console to be non functional.
- For the same reason, there is currently no upgrade path to newer OpenShift versions.
- Due to technical limitations, the CodeReady Containers cluster is ephemeral and will need to be recreated from scratch once a month using a newer release.
- The OpenShift instance is running in a virtual machine, which could cause some other differences, in particular in relation with external networking.
1.3. Minimum system requirements
CodeReady Containers requires the following minimum hardware and operating system requirements.
1.3.1. Hardware requirements
CodeReady Containers requires the following system resources:
- 4 virtual CPUs (vCPUs)
- 8 GB of memory
- 35 GB of storage space
These requirements must be met in order to run OpenShift in the CodeReady Containers virtual machine. Depending on the workload, more resources need to be assigned.
1.3.2. Operating system requirements
CodeReady Containers requires the following minimum version of a supported operating system:
1.3.2.1. Microsoft Windows
- On Microsoft Windows, CodeReady Containers requires the Windows 10 (Pro or Home) Fall Creators Update (version 1709). CodeReady Containers does not work on earlier versions or editions of Microsoft Windows.
1.3.2.2. macOS
- On macOS, CodeReady Containers requires macOS 10.12 Sierra or newer. CodeReady Containers does not work on earlier versions of macOS.
1.3.2.3. Linux
- On Linux, CodeReady Containers is only supported on Red Hat Enterprise Linux/CentOS 7.5 or newer (including 8.x versions) and on the latest two stable Fedora releases.
- When using Red Hat Enterprise Linux, the machine running CodeReady Containers must be registered with Red Hat Customer Portal.
- Ubuntu 18.04 LTS or newer and Debian 10 or newer are not officially supported and may require manual set up of the host machine.
- See Section 1.4, “Required software packages” to install the required packages for your Linux distribution.
1.4. Required software packages
CodeReady Containers requires the libvirt
and NetworkManager
packages. Consult the following table to determine the command used to install these packages for your Linux distribution.
Table 1.1. Package installation commands by distribution
Linux Distribution | Installation command |
---|---|
Fedora |
|
Red Hat Enterprise Linux/CentOS |
|
Debian/Ubuntu |
|
1.5. Installing CodeReady Containers
Prerequisites
- Your host machine must meet the Section 1.3, “Minimum system requirements”.
Procedure
-
Download the latest release of CodeReady Containers for your platform and extract the contents of the archive to a location in your
PATH
.
1.6. Setting up CodeReady Containers
The crc setup
command performs operations to set up the environment of your host machine for the CodeReady Containers virtual machine.
This procedure will create the ~/.crc
directory if it does not already exist.
Prerequisites
-
Your user account must have permission to use the
sudo
command.
The crc
binary should not be run as root
(or Administrator). The crc
binary should always be run with your user account.
Procedure
Set up your host machine for CodeReady Containers:
$ crc setup
1.7. Starting the virtual machine
The crc start
command starts the CodeReady Containers virtual machine and OpenShift cluster.
Prerequisites
-
The host machine has been set up using the
crc setup
command. For more information, see Section 1.6, “Setting up CodeReady Containers”. A valid OpenShift user pull secret. The pull secret can be copied or downloaded from the Pull Secret section of the Install on Laptop: Red Hat CodeReady Containers page on cloud.redhat.com.
NoteA Red Hat account is required in order to access the user pull secret.
Procedure
Start the CodeReady Containers virtual machine:
For native hypervisors:
$ crc start
- When prompted, supply your user pull secret.
The cluster takes a minimum of four minutes to start the necessary containers and operators before serving a request.
1.8. Accessing the OpenShift cluster
Prerequisites
- A running CodeReady Containers virtual machine. For more information, see Section 1.7, “Starting the virtual machine”.
Procedure
To access the OpenShift web console, follow these steps:
-
Run
crc console
. This will open your web browser and direct it to the web console. Log in to the OpenShift web console as the
developer
user with the password printed in the output of thecrc start
command.NoteYou can also view the password for the
developer
user by runningcrc console --credentials
.NoteThe cluster can initially be accessed through either the
kubeadmin
ordeveloper
user. For creating projects or OpenShift applications, and for application deployment, thedeveloper
user should be used. Thekubeadmin
user should only be used for administrative tasks such as creating new users, setting roles, and so on.The OpenShift documentation covers the creation of projects and applications.
See Chapter 3, Troubleshooting Red Hat CodeReady Containers if you cannot access the CodeReady Containers OpenShift cluster.
-
Run
To access the OpenShift cluster via the
oc
command, follow these steps:Run the
crc oc-env
command to print the command needed to add the cachedoc
binary to yourPATH
:$ crc oc-env
- Run the printed command.
Log in by running the
oc login -u developer https://api.crc.testing:6443
command.NoteThe password for the
developer
user was printed in the output of thecrc start
command. You can also view it by running thecrc console --credentials
command.You can now use
oc
to interact with your OpenShift cluster. For example, to verify that the OpenShift cluster operators are available using theoc get co
command:$ oc get co NAME VERSION AVAILABLE PROGRESSING FAILING SINCE authentication 4.1.0-rc.0 True False False 6d6h cloud-credential 4.1.0-rc.0 True False False 6d6h cluster-autoscaler 4.1.0-rc.0 True False False 6d6h console 4.1.0-rc.0 True False False 6d6h dns 4.1.0-rc.0 True False False 89m image-registry 4.1.0-rc.0 True False False 6d6h ingress 4.1.0-rc.0 True False False 89m kube-apiserver 4.1.0-rc.0 True False 6d6h kube-controller-manager 4.1.0-rc.0 True False 6d6h kube-scheduler 4.1.0-rc.0 True False 6d6h machine-api 4.1.0-rc.0 True False False 6d6h machine-config 4.1.0-rc.0 False False True 6d6h marketplace 4.1.0-rc.0 True False False 6d6h monitoring Unknown True Unknown 6d6h network 4.1.0-rc.0 True False 6d6h node-tuning 4.1.0-rc.0 True False False 89m openshift-apiserver 4.1.0-rc.0 True False 6d6h openshift-controller-manager 4.1.0-rc.0 True False 5d11h openshift-samples 4.1.0-rc.0 True False False 6d6h operator-lifecycle-manager 4.1.0-rc.0 True False False 6d6h operator-lifecycle-manager-catalog 4.1.0-rc.0 True False False 6d6h service-ca 4.1.0-rc.0 True False False 6d6h service-catalog-apiserver 4.1.0-rc.0 True False False 88m service-catalog-controller-manager 4.1.0-rc.0 True False False 88m storage 4.1.0-rc.0 True False False 6d6h
NoteThe
machine-config
cluster operator is expected to reportFalse
availability. Themonitoring
cluster operator is expected to reportUnknown
availability.The OpenShift documentation covers the creation of projects and applications. OpenShift Do (
odo
) can also be used to create OpenShift projects and applications from the command line.See Chapter 3, Troubleshooting Red Hat CodeReady Containers if you cannot access the CodeReady Containers OpenShift cluster.
1.9. Stopping the virtual machine
The crc stop
command stops the running CodeReady Containers virtual machine and OpenShift cluster. The stopping process will take a few minutes while the cluster shuts down.
Procedure
Stop the CodeReady Containers virtual machine and OpenShift cluster:
$ crc stop
1.10. Deleting the virtual machine
The crc delete
command deletes an existing CodeReady Containers virtual machine.
All the changes which have been made to the OpenShift cluster will be lost.
Procedure
Delete the CodeReady Containers virtual machine:
$ crc delete
Chapter 2. Common tasks
2.1. Starting Monitoring, Alerting, and Telemetry
In order to make sure CodeReady Containers can run on a typical laptop, some resource–heavy services get disabled by default. One of these is Prometheus and all the related monitoring, alerting, and telemetry functionality, with the latter being responsible for your cluster being listed in the Red Hat OpenShift Cluster Manager.
Prerequisites
-
A running CodeReady Containers virtual machine and a working
oc
command. For more information, see Section 1.8, “Accessing the OpenShift cluster”.
Procedure
Start monitoring, alerting, and telemetry services:
$ oc scale --replicas=1 statefulset --all -n openshift-monitoring; oc scale --replicas=1 deployment --all -n openshift-monitoring
Chapter 3. Troubleshooting Red Hat CodeReady Containers
The goal of Red Hat CodeReady Containers is to deliver an OpenShift environment for development and testing purposes. Issues occurring during installation or usage of specific OpenShift applications are outside of the scope of CodeReady Containers and should be reported to the relevant project. For example, OpenShift issues are tracked on GitHub.
3.1. Basic troubleshooting
The majority of issues can be resolved by stopping a running CodeReady Containers virtual machine, deleting the virtual machine, and starting a new instance of the virtual machine.
Prerequisites
-
The host machine has been set up using the
crc setup
command. For more information, see Section 1.6, “Setting up CodeReady Containers”. -
The virtual machine has been started using the
crc start
command. For more information, see Section 1.7, “Starting the virtual machine”. - You are using the latest CodeReady Containers release. The generated certificates for the embedded system image bundle expire after 30 days. Using an older system image bundle may result in errors related to expired x509 certificates. For more information, see Section 3.4, “Troubleshooting expired certificates”.
Procedure
To troubleshoot CodeReady Containers, perform the following steps:
Stop the CodeReady Containers virtual machine:
$ crc stop
Delete the CodeReady Containers virtual machine:
$ crc delete
Start the CodeReady Containers virtual machine:
$ crc start
NoteThe cluster takes a minimum of four minutes to start the necessary containers and operators before serving a request.
If your issue has not been resolved by this procedure, perform the following steps:
- Search open issues for the issue that you are encountering.
-
If no existing issue addresses the encountered issue, create an issue and attach the
~/.crc/crc.log
file to the created issue. The~/.crc/crc.log
file contains detailed debugging and troubleshooting information which can help diagnose the problem that you are experiencing.
3.2. Getting shell access to the OpenShift cluster
Direct access to the OpenShift cluster is not needed for regular cluster use, and is strongly discouraged. If such access is needed for troubleshooting or debugging purposes, follow these steps:
-
Enable
oc
access to the cluster, logging in askubeadmin
. For detailed steps, see Section 1.8, “Accessing the OpenShift cluster”. Run
oc get nodes
. The output will be similar to this:$ oc get nodes NAME STATUS ROLES AGE VERSION crc-shdl4-master-0 Ready master,worker 7d7h v1.14.6+7e13ab9a7
-
Run
oc debug nodes/crc-shdl4-master-0
wherecrc-shdl4-master-0
is the name of the node which was printed at the previous step.
3.3. DNS configuration details
This section describes how CodeReady Containers configures networking. This can be useful for troubleshooting, or in case you are using a non-standard DNS setup, and want to adjust it for CodeReady Containers needs. The crc ip
command can be used to obtain the VM IP address as needed. This address can change each time the VM is restarted.
3.3.1. Linux
- CodeReady Containers expects NetworkManager to be used to manage networking.
-
NetworkManager is set up to use dnsmasq through the
/etc/NetworkManager/conf.d/crc-nm-dnsmasq.conf
configuration file. -
The configuration file for this dnsmasq instance is
/etc/NetworkManager/dnsmasq.d/crc.conf
:
server=/crc.testing/192.168.130.11 server=/apps-crc.testing/192.168.130.11
-
NetworkManager dnsmasq instance forwards requests for the
crc.testing
andapps-crc.testing
domains to the 192.168.130.11 DNS server which is a dnsmasq instance running inside the virtual machine.
3.3.2. macOS
-
CodeReady Containers creates a
/etc/resolver/testing
file which instructs macOS to forward all DNS requests for thetesting
domain to the CodeReady Containers virtual machine. -
CodeReady Containers also adds an
api.crc.testing
entry to/etc/hosts
pointing at the VM IP address. This is needed by theoc
binary, see OpenShift issue #23266.
3.4. Troubleshooting expired certificates
Prior to Red Hat CodeReady Containers 1.2.0, the system bundle included in each released crc
binary expired 30 days after the release due to certificates embedded in the OpenShift cluster. Using an older crc
binary or system bundle will result in an expired certificates error.
Starting from CodeReady Containers 1.2.0, the embedded certificates can be automatically renewed by crc. The certificate renewal process is triggered when needed when crc start
is run. When certificates need to be renewed, this can add up to five minutes to the start time of the cluster.
Procedure
With CodeReady Containers releases older than 1.2.0, to resolve expired certificate errors:
-
Download the latest CodeReady Containers release and place the
crc
binary in your$PATH
. Remove the cluster with certificate errors using the
crc delete
command:$ crc delete
NoteThe
crc delete
command will result in the loss of data stored in the CodeReady Containers virtual machine.Set up the new release:
$ crc setup
Start the new cluster:
$ crc start