Github Runner Fallback Action

Github action to determine the availability of self-hosted runners, and fallback to a GitHub runner if the primary runners are offline.

This action uses GitHub API to check the statuses of self hosted-runners that match specific labels, and outputs the runner label(s), or a fallback runner if the self-hosted runner(s) is unavailable.

This output can then used on the runs-on property of subsequent jobs.

Note: In order to support an array of labels for the runs-on field, the output is formatted as a JSON string and needs to be parsed using fromJson. See example usage below.

Usage

jobs:
  # Job to 
  determine-runner:
    runs-on: ubuntu-latest
    outputs:
      runner: ${{ steps.set-runner.outputs.use-runner }}
    steps:
      - name: Determine which runner to use
        id: set-runner
        uses: jimmygchen/runner-fallback-action@v1
        with:
          primary-runner: "self-hosted,linux"
          fallback-runner: "ubuntu-latest"
          github-token: ${{ secrets.YOUR_GITHUB_TOKEN }}

  another-job:
    needs: determine-runner
    runs-on: ${{ fromJson(needs.determine-runner.outputs.runner) }}
    steps:
      - name: Do something
        run: echo "Doing something on ${{ needs.determine-runner.outputs.runner }}"

Credit: this action is based on the pattern described by @ianpurton on this feature request thread.