Using Flux on OpenShift

OpenShift Setup

Steps described in this document have been tested on OpenShift 4.6 only. You require cluster-admin privileges to install Flux on OpenShift. This means that it currently is not possible to install Flux on the OpenShift Developer Sandbox.

CodeReady Containers

An easy way to provision OpenShift is to use CodeReady Containers (CRC) for OpenShift, which could be obtained from here. With this setup, you require a physical Linux box. An OpenShift cluster will run inside a VM installed by CRC.

# Setup the OpenShift configuration
# You need to paste a pull secret here
crc setup

# Start the cluster with 18 GB of RAM
crc start -c 4 -m 18432

After the cluster is up and running, there will be a message tell us how to login. Please make sure that you use kubeadmin user to login before installing Flux.

# Prepare environment setup for the OC command
eval $(crc oc-env)

# Login 
oc login -u kubeadmin -p <your password> https://api.crc.testing:6443

Security Context Constraints

Before installing Flux, you need to set the privileged security context constraint for the following controller in the flux-system namespace.

NS="flux-system"
oc adm policy add-scc-to-user privileged system:serviceaccount:$NS:source-controller
oc adm policy add-scc-to-user privileged system:serviceaccount:$NS:kustomize-controller
oc adm policy add-scc-to-user privileged system:serviceaccount:$NS:image-automation-controller
oc adm policy add-scc-to-user privileged system:serviceaccount:$NS:image-reflector-controller

Flux Installation with CLI

The best way to install Flux on OpenShift currently is to use the flux bootstrap command. This command works with GitHub, GitLab as well as generic Git provider. Please refer to the command’s documentations here in details.

Assuming that you are a GitHub user, you could start by preparing your GitHub credentials.

export GITHUB_TOKEN=<your-token>
export GITHUB_USER=<your-username>

Then simply bootstrap Flux.

flux bootstrap github \
  --owner=$GITHUB_USER \
  --repository=openshift-gitops \
  --branch=main \
  --path=./clusters/my-cluster \
  --personal

and enjoy your GitOps on OpenShift.

Flux Upgrade

Upgrading Flux on OpenShift is very simple and straightforward. Please just make sure that you are already logged in as kubeadmin user. Assuming you are a Homebrew user, you could upgrade Flux CLI using the following command.

# Upgrade Flux
brew upgrade fluxcd/tap/flux

# Check Flux version
flux -v

# Login as kubeadmin
oc login -u kubeadmin -p <your password> https://api.crc.testing:6443

After you obtained the Flux version you wanted, simply re-run the above flux bootstrap command from the previous section, and all of your Flux component will be upgraded.

# Re-running the bootstrap command to upgrade
flux bootstrap github \
  --owner=$GITHUB_USER \
  --repository=openshift-gitops \
  --branch=main \
  --path=./clusters/my-cluster \
  --personal

Please see also the upgrade and the bootstrap upgrade documentations for details.