Nikola JokicandCopilot App
41d05325c2
An outdated runner used to flip the whole scale set into the Outdated
phase permanently, which tears down the listener and switches the scale
set off. That verdict outlived the runner spec it was about: a runner
busy with a job survives the revision cleanup that follows a spec
update, and only reports Outdated once the job finishes. The result was
that a freshly applied fix could be discarded by a runner that never ran
it.
Runners are now stamped with the actionable revision they were built
from. An Outdated runner whose revision is behind the applied revision is
considered stale: it is deleted so the scaling logic replaces it with one
built from the current spec, and it no longer contributes to the set's
phase. A runner at the current revision still marks the set Outdated, so
a genuinely bad spec is still surfaced.
Two supporting fixes:
- patchAppliedActionableRevisionStatus now recomputes the phase in both
directions. It only ever forced Running, so the early-return path
could leave a stale Outdated behind.
- The AutoscalingRunnerSet only tears down on an Outdated set once that
set has applied its current actionable revision. Otherwise a spec
update races the EphemeralRunnerSet controller and the teardown fires
against a phase that predates the update.
Runners created before this change parse to revision 0, which matches
the zero value of AppliedActionableRevision, so they are treated as
current until a revision is actually applied.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Actions Runner Controller (ARC)
About
Actions Runner Controller (ARC) is a Kubernetes operator that orchestrates and scales self-hosted runners for GitHub Actions.
With ARC, you can create runner scale sets that automatically scale based on the number of workflows running in your repository, organization, or enterprise. Because controlled runners can be ephemeral and based on containers, new runner instances can scale up or down rapidly and cleanly. For more information about autoscaling, see "Autoscaling with self-hosted runners."
You can set up ARC on Kubernetes using Helm, then create and run a workflow that uses runner scale sets. For more information about runner scale sets, see "Deploying runner scale sets with Actions Runner Controller."
People
Actions Runner Controller (ARC) is an open-source project currently developed and maintained in collaboration with the GitHub Actions team, external maintainers @mumoshu and @toast-gear, various contributors, and the awesome community.
If you think the project is awesome and is adding value to your business, please consider directly sponsoring community maintainers and individual contributors via GitHub Sponsors.
If you are already the employer of one of the contributors, sponsoring via GitHub Sponsors might not be an option. Just support them by other means!
See the sponsorship dashboard for the former and the current sponsors.
Getting Started
To give ARC a try with just a handful of commands, please refer to the Quickstart guide.
For an overview of ARC, please refer to About ARC.
With the introduction of autoscaling runner scale sets, the existing autoscaling modes are now legacy. The legacy modes have certain use cases and will continue to be maintained by the community only.
For further information on what is supported by GitHub and what's managed by the community, please refer to this announcement discussion.
Documentation
ARC documentation is available on docs.github.com.
Legacy documentation
The following documentation is for the legacy autoscaling modes that continue to be maintained by the community:
- Quickstart guide
- About ARC
- Installing ARC
- Authenticating to the GitHub API
- Deploying ARC runners
- Adding ARC runners to a repository, organization, or enterprise
- Automatically scaling runners
- Using custom volumes
- Using ARC runners in a workflow
- Managing access with runner groups
- Configuring Windows runners
- Using ARC across organizations
- Using entrypoint features
- Deploying alternative runners
- Monitoring and troubleshooting
Contributing
We welcome contributions from the community. For more details on contributing to the project (including requirements), please refer to "Getting Started with Contributing."
Troubleshooting
We are very happy to help you with any issues you have. Please refer to the "Troubleshooting" section for common issues.