Migrate from Actions Runner Controller (ARC) to Managed Runners

By Kaveh Alemi·Latchkey

ARC works, but you maintain a Kubernetes cluster, the controller, and scaling config to get ephemeral runners. Managed runners give you ephemeral runners with none of that.

Actions Runner Controller (ARC) runs self-hosted runners as pods and scales them with runner scale sets. It is real infrastructure: a cluster, the controller, listeners, and upgrade cycles. Managed runners replace the whole stack with a runs-on: label.

What changes

Before and after

jobs:
  build:
    runs-on: arc-runner-set   # ARC runner scale set
    steps:
      - uses: actions/checkout@v4
      - run: npm ci && npm test

Managed equivalent

jobs:
  build:
    runs-on: latchkey-medium   # no cluster to run
    steps:
      - uses: actions/checkout@v4
      - run: npm ci && npm test

Migration steps

1. Inventory which workflows target your ARC runner scale set labels.
2. Connect the managed-runner provider to your org.
3. Swap the ARC label for the managed label on one workflow.
4. Verify parity, roll out, then scale the ARC deployment to zero.
5. Tear down the controller and (if dedicated) the cluster.

Gotchas

• If jobs relied on in-cluster services or node-local mounts, replace those with services: containers or steps.
• Container-mode ARC jobs may need container: on GitHub-managed runners.
• Keep ARC scaled down (not deleted) until you have run in parallel and trust the new path.

What you gain

• Roughly 70% lower per-minute cost than GitHub-hosted runners.
• Warm pools remove queue time - jobs start almost immediately.
• Self-healing detects, fixes, and auto-retries transient and mechanical failures.
• Zero ops: no agents, autoscalers, or controllers to patch and babysit.

Key takeaways

• ARC trades GitHub-hosted cost for cluster + controller upkeep.
• Managed runners give ephemeral runners with no cluster.
• Migration is a label swap, then scale ARC to zero.

Frequently asked questions

Related guides

References

• GitHub Actions documentation