Nikola JokicandCopilot App
810127e8d9
The neighbouring applied-revision helper refuses to move its marker backwards, so the obvious tidy-up is to make this one match. That would break it. Applied revisions derive from metadata.generation and only ever climb. Listener patch IDs do not. setDesiredWorkerState publishes 0 whenever the set is idle at MinRunners with nothing dirty, restarts its sequence from 0 when the listener restarts, and wraps explicitly at MaxInt32, so Spec.PatchID legitimately moves down. The marker only means "the gap below Spec.Replicas was created by cleaning up for exactly this patch ID", so it has to follow the patch ID wherever it goes. A marker that refused to descend would sit above every value the listener went on to publish, and since the guard suppresses only on an exact match, suppression would never fire again -- silently disabling the behaviour this layer adds. This also settles what the optimistic lock is and is not for. It cannot make an older patch ID unwritable, because the retry re-reads and re-applies the same argument, and recording the patch ID whose cleanup actually happened is a true statement regardless of ordering. What it prevents is a write decided against state that has since changed. The test pins the descending case, so a future reader who reaches for >= gets a failure rather than a silently inert guard. 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.