Deploy GitHub Actions runner scale sets on Kubernetes with Actions Runner Controller (ARC)

Steps

1. Install the ARC controller Helm chart: helm install arc --namespace arc-systems --create-namespace oci://ghcr.io/actions/actions-runner-controller-charts/gha-runner-scale-set-controller
2. Create a Kubernetes secret holding a GitHub App private key or a PAT with repo/org scope, then reference it in your scale-set values file
3. Install a runner scale set Helm chart, setting githubConfigUrl to your repo or org URL and githubConfigSecret to the secret name: helm install arc-runners --namespace arc-runners --create-namespace -f values.yaml oci://ghcr.io/actions/actions-runner-controller-charts/gha-runner-scale-set
4. In values.yaml set minRunners and maxRunners to control the autoscaling bounds, and set runnerScaleSetName to the label workflows will reference in runs-on
5. Target the scale set from a workflow with runs-on: arc-runners (matching runnerScaleSetName); ARC provisions a runner pod per queued job and terminates it after completion
6. Monitor scale-set activity with kubectl logs -n arc-systems deployment/arc-gha-runner-scale-set-controller and check runner pod status in the arc-runners namespace