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Contributing to OpenShift

The OpenShift architecture builds upon the flexibility and scalability of Docker and Kubernetes to deliver a powerful new Platform-as-a-Service system. This article explains how to set up a development environment and get involved with this latest version of OpenShift. Kubernetes is included in this repo for ease of development, and the version we include is periodically updated.

To get started you can either:

Or if you are interested in development, start with:

Download from GitHub

The OpenShift team periodically publishes binaries to GitHub on the Releases page. These are Linux, Windows, or Mac OS X 64bit binaries (note that Mac and Windows are client only). You’ll need Docker installed on your local system (see the installation page if you’ve never installed Docker before and you’re not on RHEL/CentOS/Fedora).

The tar file for each platform contains a single binary openshift which is the all-in-one OpenShift installation.

  • Use oc cluster up to launch the server.

  • Use oc login <server> …​ to connect to an OpenShift server

  • Use openshift help to see more about the commands in the binary

OpenShift Development

To get started, fork the origin repo.

Develop locally on your host

You can develop OpenShift on Windows, Mac, or Linux, but you’ll need Docker installed on Linux to actually launch containers. Client and server binaries can be built locally or in the openshift/origin-release container environment. The Go programming language is only necessary for building on the local host.

Currently, OpenShift is built with go 1.9 and uses Docker 1.13 on Fedora/CentOS/RHEL. MacOS supports builds with go 1.9 and Docker CE 17.09.1 - newer versions of go and Docker are not supported. The exact requirement for Docker is documented here.

Installing Prerequisites

MacOS

Follow the installation steps to install Homebrew, which will allow you to install git:

$ brew install git

Then, follow the instructions to install docker. Search the Docker for Mac releases to find a supported version to download. You will need to build linux/amd64 binaries for the OpenShift server; if you want to do the builds locally, you will need to follow the instructions to install the go programming language. Go pkg installers can be downloaded here.

Windows

Follow the installation steps to install git for Windows and docker. Search the Docker for Windows releases to find a supported version to download. You will need to build linux/amd64 binaries for the OpenShift server; if you want to do the builds locally, you will need to follow the instructions to install the go programming language. Go msi installers can be downloaded here.

Fedora

Install git and docker with:

$ sudo dnf install git docker-latest

In order to do builds locally, install the following build dependencies:

$ sudo dnf install golang golang-race make gcc zip mercurial krb5-devel bsdtar bc rsync bind-utils file jq tito createrepo openssl gpgme gpgme-devel libassuan libassuan-devel
CentOS / RHEL

Install git and docker with:

$ sudo yum install git docker

In order to do builds locally, install the following build dependencies:

$ sudo yum install golang make gcc zip mercurial krb5-devel bsdtar bc rsync bind-utils file jq tito createrepo openssl gpgme gpgme-devel libassuan libassuan-devel

Configuring a Development Environment

  1. Create a Go workspace directory:

    $ mkdir $HOME/go
  2. In your .bashrc file or .bash_profile file, set a GOPATH and update your PATH:

    export GOPATH=$HOME/go
    export PATH=$PATH:$GOPATH/bin
    export OS_OUTPUT_GOPATH=1
  3. Open up a new terminal or source the changes in your current terminal. Then clone your forked repo:

    $ mkdir -p $GOPATH/src/github.com/openshift
    $ cd $GOPATH/src/github.com/openshift
    $ git clone git://github.com/<forkid>/origin  # Replace <forkid> with the your github id
    $ cd origin
    $ git remote add upstream git://github.com/openshift/origin
  4. You are now ready to edit the source, build and restart OpenShift to test your changes.

Building Origin Binaries, RPMs and Images

In order to build the base and release images for use by the release build and image build, run:

$ hack/env hack/build-base-images.sh
Note
Avoiding above step can cause below error while running 'hack/env make release'
"openshift/origin-pod: unable to pull image (from: openshift/origin-source, tag: latest): API error (404): {"message":"repository openshift/origin-source not found: does not exist or no pull access"}"

In order to build a full release of Origin, containing binaries, RPMs and container images, run:

$ hack/env make release

In order to make use of the binaries from your shell, add the build output directory to the $PATH:

$ export PATH="$( source hack/lib/init.sh; echo "${OS_OUTPUT_BINPATH}/$( os::build::host_platform )/" ):${PATH}"

See more information in HACKING.md for a more in-depth approach to building releases and incremental artifacts.

Running the OpenShift Server

Next, follow the set-up steps in cluster_up_down.md to start a cluster with oc cluster up. When starting the cluster, you will need to use container images. Images built locally with the make release and hack/build-images.sh scripts are tagged with the git commit you’re working off of as well as :latest. If you have not built all of the images locally, ask oc cluster up for the :latest version and any missing images will be pulled down:

$ oc cluster up --tag=latest

If you have built a full suite of images and want to ensure that only the images you just built are going to be used, ask oc cluster up for the version that corresponds to your git commit:

$ oc cluster up --tag="$(git log -1 --pretty=%h )"
Note
The --tag flag can be used only for development purposes. It is not meant for running a cluster of a different version than oc binary.

Develop and test using a docker-in-docker cluster

It’s possible to run an OpenShift multinode cluster on a single host thanks to docker-in-docker (dind). Cluster creation is cheaper since each node is a container instead of a VM. This was initially implemented to support multinode network testing, but has proven useful for development as well.

Prerequisites:

  1. A host running docker and with SELinux disabled.

  2. It is acceptable to load some kernel modules (overlay and openvswitch) on the docker host.

  3. An environment with the tools necessary to build origin.

  4. A clone of the origin repo.

From the root of the origin repo, run the following command to launch a new cluster:

# -b to build origin, -i to build images
$ hack/dind-cluster.sh start -b -i

Once the cluster is up, source the cluster’s rc file to configure the environment to use it:

$ . dind-openshift.rc

Now the 'oc' command can be used to interact with the cluster:

$ oc get nodes

It’s also possible to login to the participating containers (openshift-master, openshift-node-1, openshift-node-2, etc) via docker exec:

$ docker exec -ti openshift-master bash

While it is possible to manage the OpenShift daemon in the containers, dind cluster management is fast enough that the suggested approach is to manage at the cluster level instead.

Invoking the dind-cluster.sh script without arguments will provide a usage message:

Usage: hack/dind-cluster.sh {start|stop|restart|...}

Additional documentation of how a dind cluster is managed can be found at the top of the dind-cluster.sh script.

Attempting to start a cluster when one is already running will result in an error message from docker indicating that the named containers already exist. To redeploy a cluster use the 'start' command with the '-r' flag to remove an existing cluster.

Testing networking with docker-in-docker

It is possible to run networking tests against a running docker-in-docker cluster (i.e. after 'hack/dind-cluster.sh start' has been invoked):

$ OPENSHIFT_CONFIG_ROOT=dind test/extended/networking.sh

Since a cluster can only be configured with a single network plugin at a time, this method of invoking the networking tests will only validate the active plugin. It is possible to target all plugins by invoking the same script in 'ci mode' by not setting a config root:

$ test/extended/networking.sh

In ci mode, for each networking plugin, networking.sh will create a new dind cluster, run the tests against that cluster, and tear down the cluster. The test dind clusters are isolated from any user-created clusters, and test output and artifacts of the most recent test run are retained in /tmp/openshift-extended-tests/networking.

It’s possible to override the default test regexes via the NETWORKING_E2E_FOCUS and NETWORKING_E2E_SKIP environment variables. These variables set the '-focus' and '-skip' arguments supplied to the ginkgo test runner.

To debug a test run with delve, make sure the dlv executable is installed in your path and run the tests with DLV_DEBUG set:

$ DLV_DEBUG=1 test/extended/networking.sh

Running networking tests against any cluster

It’s possible to run networking tests against any cluster. To target the default vm dev cluster:

$ OPENSHIFT_CONFIG_ROOT=dev test/extended/networking.sh

To target an arbitrary cluster, the config root (parent of openshift.local.config) can be supplied instead:

$ OPENSHIFT_CONFIG_ROOT=[cluster config root] test/extended/networking.sh

It’s also possible to supply the path to a kubeconfig file:

$ OPENSHIFT_TEST_KUBECONFIG=./admin.kubeconfig test/extended/networking.sh

See the script’s inline documentation for further details.

Running Kubernetes e2e tests

It’s possible to target the Kubernetes e2e tests against a running OpenShift cluster. From the root of an origin repo:

$ pushd ..
$ git clone http://github.com/kubernetes/kubernetes/
$ pushd kubernetes/build
$ ./run hack/build-go.sh
$ popd && popd
$ export KUBE_ROOT=../kubernetes
$ hack/test-kube-e2e.sh --ginkgo.focus="[regex]"

The previous sequence of commands will target a vagrant-based OpenShift cluster whose configuration is stored in the default location in the origin repo. To target a dind cluster, an additional environment variable needs to be set before invoking test-kube-e2e.sh:

$ export OS_CONF_ROOT=/tmp/openshift-dind-cluster/openshift

Development: What’s on the Menu?

Right now you can see what’s happening with OpenShift development at:

Ready to play with some code? Hop down and read up on our roadmap for ideas on where you can contribute. You can also try to take a stab at any issue tagged with the help-wanted label.

If you are interested in contributing to Kubernetes directly:
Join the Kubernetes community and check out the contributing guide.

Troubleshooting

If you run into difficulties running OpenShift, start by reading through the troubleshooting guide.

The Roadmap

The OpenShift project roadmap lives on Trello. A summary of the roadmap, releases, and other info can be found here.

Stay in Touch

Reach out to the OpenShift team and other community contributors through IRC and our mailing list: