Self-Hosted CI/CD: Running GitHub Actions Runners on k3s
TL;DR Running self-hosted GitHub Actions runners on the same k3s cluster they deploy to is a powerful pattern. GitHub Actions Runner Controller (ARC) manages runner pods as Kubernetes resources, scaling them based on workflow demand. This post covers the full setup, the RBAC model that makes it work, and every gotcha I encountered. Why Self-Hosted Runners? GitHub-hosted runners are convenient but have limitations: Cost: Free tier gives 2,000 minutes/month. With 5+ repositories doing multiple deploys per day, that burns fast. Speed: GitHub-hosted runners are shared infrastructure. Cold starts take 20-30 seconds, and you are competing with other users. Access: GitHub-hosted runners cannot reach my private cluster network. Every deployment would need a VPN or tunnel. Control: I want to install whatever tools I need (kubectl, helm, terraform, ansible) without Docker layer caching tricks. Self-hosted runners solve all of these: they run inside the cluster, have direct network access to all services, pre-configured tools, and no usage limits. ...