cache-cleaner.yml

# Example taken from https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#managing-caches
name: Cleanup Caches on Pull Request Merge
on:
  pull_request:
    types:
      - closed

permissions:  # added using https://github.com/step-security/secure-repo
  contents: read

jobs:
  cleanup:
    name: Cleanup
    runs-on: ubuntu-latest
    permissions:
      actions: write
    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@0080882f6c36860b6ba35c610c98ce87d4e2f26f # v2.10.2
        with:
          disable-sudo: true
          egress-policy: block
          allowed-endpoints: >
            api.github.com:443
            github.com:443
            objects.githubusercontent.com:443

      - name: Checkout Repository
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2

      - name: Cleanup
        run: |
          gh extension install actions/gh-actions-cache

          REPO=${{ github.repository }}
          BRANCH="refs/pull/${{ github.event.pull_request.number }}/merge"

          echo "Fetching list of cache key"
          cacheKeysForPR=$(gh actions-cache list -R $REPO -B $BRANCH -L 100 | cut -f 1 )

          ## Setting this to not fail the workflow while deleting cache keys.
          set +e
          echo "Deleting caches..."
          for cacheKey in $cacheKeysForPR
          do
              gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
          done
          echo "Done"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}