Running GitHub Actions Runners on Azure Container Apps with KEDA Autoscaling

This guide explains launching self-hosted GitHub Actions runners on Azure Container Apps Jobs using KEDA for autoscaling. The architecture involves developers triggering workflows that are then processed by a KEDA-monitored GitHub API. KEDA triggers Azure Container App Jobs, spinning up ephemeral containers that register as runners, execute jobs, and then terminate. This approach offers cost optimization, control over the execution environment, and network access to private resources. The setup requires a GitHub PAT, Azure resources like ACR, Key Vault, and Container Apps, and a Docker image. Runner groups are recommended for organization-level runners. The guide details creating these resources in the Azure portal, building the runner's Docker image, and configuring KEDA to scale runners based on GitHub Actions job queue.