astro/.github/workflows/cleanup-cache.yml

name: Cleanup cache

on:
  schedule:
    - cron: "0 11 * * *"
  pull_request:
    types:
      - closed

jobs:
  cleanup:
    runs-on: ubuntu-latest
    steps:
      - name: Check out code
        uses: actions/checkout@v3

      - name: Cleanup caches older than 5 days
        if: github.event_name == 'schedule'
        uses: MyAlbum/purge-cache@v2
        with:
          max-age: 432000

      # https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#force-deleting-cache-entries
      - name: Cleanup on PR close
        if: github.event_name == 'pull_request'
        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 }}