GitHub Actions Runner Controller (ARC) for OpenShift 4.X

Source : https://github.com/actions-runner-controller/actions-runner-controller

There are multiple ways of installing ARC, I have chosen to use GitHub Apps to store credentials and access controls and to configure my runners at the Org level so that all repos underneath could have access to them. I also will install everything using .yaml files vs Helm.

Cert-Manager Installation

Prior to installing ARC, you will need to install and configure cert-manager, this can be done by installing the cert-manager operator from the Operator Hub. Once the operator is installed (using the defaults), we will need to setup the private CA cert & key.

1. Copy your ca.crt & ca.key files locally
2. Create a SECRET with these files in the openshift-operators namespace
   oc create secret tls ca-key-pair --cert=ca.crt --key=ca.key
3. I chose to provide acces to the cluster by creating a kind ClusterIssuer

  kind: ClusterIssuer
  apiVersion: cert-manager.io/v1
  metadata:
    name: redcloud-clusterissuer
  spec:
    selfSigned:
      ca:
        secretName: ca-key-pair

ARC Installation

Releases : https://github.com/actions-runner-controller/actions-runner-controller/releases/

1. Install the current release
   kubectl create -f https://github.com/actions-runner-controller/actions-runner-controller/releases/download/v0.25.0/actions-runner-controller.yaml
2. When deploying the solution for a GHES environment you need to provide an additional environment variable as part of the controller deployment
   kubectl set env deploy controller-manager -c manager GITHUB_ENTERPRISE_URL=https://git.redcloud.land --namespace actions-runner-system
3. Prior to 0.25 you have to set privileged access
   oc adm policy add-scc-to-user privileged -z default -n actions-runner-system

Deploying Using GitHub App Authentication

You can create a GitHub App for either your user account or any organization, below are the app permissions required for each supported type of runner.

Required Permissions for Repository Runners:

• Actions (read)
• Administration (read / write)
• Checks (read) (if you are going to use Webhook Driven Scaling)
• Metadata (read)

Required Permissions for Organization Runners:

• Actions (read)
• Metadata (read)

Organization Permissions

• Self-hosted runners (read / write)

GitHub App for your organization

1. Replace the :org part of the following URL with your organization name before opening it. Then enter any unique name in the "GitHub App name" field, and hit the "Create GitHub App" button at the bottom of the page to create a GitHub App.

   https://github.com/organizations/:org/settings/apps/new?url=http://github.com/actions-runner-controller/actions-runner-controller&webhook_active=false&public=false&administration=write&organization_self_hosted_runners=write&actions=read&checks=read

   You will see an App ID on the page of the GitHub App you created as follows, the value of this App ID will be used later.

2. Download the private key file by pushing the "Generate a private key" button at the bottom of the GitHub App page. This file will also be used later.

3. Go to the "Install App" tab on the left side of the page and install the GitHub App that you created for your account or organization.

   NOTE: When the installation is complete, you will be taken to a URL in one of the following formats, the last number of the URL will be used as the Installation ID later (For example, if the URL ends in settings/installations/12345, then the Installation ID is 12345).

4. Register the App ID (APP_ID), Installation ID (INSTALLATION_ID), and the downloaded private key file (PRIVATE_KEY_FILE_PATH) to OpenShift as a secret.

$ kubectl create secret generic controller-manager \
    -n actions-runner-system \
    --from-literal=github_app_id=${APP_ID} \
    --from-literal=github_app_installation_id=${INSTALLATION_ID} \
    --from-file=github_app_private_key=${PRIVATE_KEY_FILE_PATH}

Runner Deployments

There are additional ways to launch your runners, here I chose using kind: RunnerDeployment

NOTE: Keep in mind that OpenShift will not natively display your deployments, to view them as well as the later HorizontalRunnerAutoscaler, you'll need to use the full name oc get runnerdeployment, oc get hra & oc get horizonalrunnerautoscaler.

kind: RunnerDeployment
metadata:
  name: example-runner-deployment
spec:
  template:
    spec:
      repository: example/myrepo
---
apiVersion: actions.summerwind.dev/v1alpha1
kind: HorizontalRunnerAutoscaler
metadata:
  name: example-runner-deployment-autoscaler
spec:
  scaleTargetRef:
    name: example-runner-deployment
  minReplicas: 1
  maxReplicas: 5
  metrics:
  - type: TotalNumberOfQueuedAndInProgressWorkflowRuns
    repositoryNames:
    - example/myrepo

There are a lot of options here, so I am only showing the defaults, but if you'd like an example I have included my scripts under /manifests. Additionally, I have evaluated two custom runners - one based on docker and the other based on podman (buildah). I will include these as examples under /builds.