cache-cleanup.yml

# Delete all GitHub Actions caches scoped to a pull request when it is closed
#
# See: https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows

name: cache-cleanup

# WARNING be sure this workflow never accesses anything from the PR contents
on:
  pull_request_target:
    types:
      - closed

permissions:
  contents: read

jobs:
  cleanup:
    name: Delete caches for closed PR
    runs-on: ubuntu-24.04
    permissions:
      # Required for `gh cache delete`
      actions: write
      contents: read
    steps:
      - name: Delete caches scoped to this PR
        env:
          GH_TOKEN: ${{ github.token }}
          GH_REPO: ${{ github.repository }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
        run: |
          set -eu
          for PR_REF in "refs/pull/${PR_NUMBER}/merge" "refs/pull/${PR_NUMBER}/head"; do
             echo "Caches currently scoped to ${PR_REF}:"
             if ! gh cache list --ref "${PR_REF}" --limit 100; then
               echo "::warning::Unable to list caches for ${PR_REF}"
             fi
             if ! gh cache delete --all --ref "${PR_REF}"; then
               echo "::warning::Unable to delete caches for ${PR_REF}"
             fi
           done