cache-cleanup.yml

# Cache Cleanup
#
# Delete caches when a pull request is closed or on workflow dispatch.
#
# References:
#
# - https://docs.github.com/actions/learn-github-actions/contexts
# - https://docs.github.com/actions/learn-github-actions/expressions
# - https://docs.github.com/actions/using-workflows/caching-dependencies-to-speed-up-workflows#force-deleting-cache-entries
# - https://docs.github.com/actions/using-workflows/events-that-trigger-workflows#pull_request
# - https://docs.github.com/actions/using-workflows/events-that-trigger-workflows#workflow_dispatch
# - https://docs.github.com/actions/using-workflows/using-github-cli-in-workflows
# - https://docs.github.com/webhooks-and-events/webhooks/webhook-events-and-payloads#pull_request
# - https://docs.github.com/webhooks-and-events/webhooks/webhook-events-and-payloads#workflow_dispatch
# - https://github.com/actions/checkout
# - https://github.com/actions/gh-actions-cache
# - https://github.com/hmarr/debug-action

---
name: cache-cleanup
on:
  pull_request:
    types:
      - closed
  workflow_dispatch:
    inputs:
      all:
        default: false
        description: delete caches without filtering by branch
        type: boolean
permissions:
  actions: write
env:
  BRANCH: |
    ${{ github.event.number && format('refs/pull/{0}/merge', github.event.number) || github.ref }}
  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
concurrency:
  cancel-in-progress: true
  group: ${{ github.workflow }}-${{ format('refs/heads/{0}', github.head_ref || github.ref_name) }}
jobs:
  cache-cleanup:
    runs-on: ubuntu-latest
    steps:
      - id: debug
        name: Print environment variables and event payload
        uses: hmarr/debug-action@v2.1.0
      - id: checkout
        name: Checkout main
        uses: actions/checkout@v3.5.2
        with:
          persist-credentials: false
          ref: main
      - id: gh-actions-cache
        name: Install actions/gh-actions-cache
        run: gh extension install actions/gh-actions-cache
      - id: cleanup
        name: Delete caches${{ !inputs.all && format(' created by {0}', env.BRANCH) || '' }}
        env:
          BRANCH_FILTER: ${{ !inputs.all && format('--branch {0}', env.BRANCH) || '' }}
        run: |
          # prevent workflow failure while deleting cache keys
          set +e

          # delete all caches or caches created by ${{ env.BRANCH }}
          for key in $(gh actions-cache list $BRANCH_FILTER --limit 100 | cut -f 1); do
            gh actions-cache delete $key $BRANCH_FILTER --confirm
          done