cleanup_cache.yml

name: cleanup caches
on:
  pull_request:
    types:
      - closed

jobs:
  cleanup:
    runs-on: ubuntu-latest

    permissions:
      # `actions:write` permission is required to delete caches
      actions: write
      contents: read

    steps:
      - name: Check out code
        uses: actions/checkout@v3

      - 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 for ${BRANCH}"
          cacheKeysForPR=$(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

          BRANCH="master"
          echo "Fetching list of cache key for ${BRANCH}"
          cacheKeysForPR=$(gh actions-cache list -R $REPO -B $BRANCH -L 100 | cut -f 1 )
          echo "${cacheKeysForPR[*]}"
          cacheKeysForPRSliced = ("${cacheKeysForPR[@]:1}")
          echo "${cacheKeysForPRSliced[*]}"
          ## Setting this to not fail the workflow while deleting cache keys.
          set +e
          echo "Deleting caches..."
          for cacheKey in cacheKeysForPRSliced
          do
              # gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
              echo "${cacheKey}"
          done
          echo "Done"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}