clean-cache-post-merge.yml

# Copied from
# https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#usage-limits-and-eviction-policy
name: cleanup caches by a branch
on:
  pull_request_target:
    types:
      - closed
  workflow_dispatch:
    inputs:
      branch:
        description: "Branch name"
        required: false
        default: ""
jobs:
  cleanup:
    runs-on: ubuntu-latest
    timeout-minutes: 15
    permissions:
      actions: write
    steps:
      - name: Setup Branch Name
        id: setup-branch
        run: |
          if [ "${{ github.event.inputs.branch }}" != "" ]; then
            echo "branch=${{ github.event.inputs.branch }}" >> $GITHUB_OUTPUT
          elif [ "${{ github.head_ref }}" != "" ]; then
            echo "branch=${{ github.head_ref }}" >> $GITHUB_OUTPUT
          else
            echo "branch=${{ github.ref_name }}" >> $GITHUB_OUTPUT
          fi
      - name: Cleanup
        run: |
          gh extension install actions/gh-actions-cache

          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
              echo "Deleting $cacheKey"
              gh actions-cache delete $cacheKey -R $REPO -B $BRANCH --confirm
          done
          echo "Done"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          REPO: ${{ github.repository }}
          BRANCH: ${{ steps.setup-branch.outputs.branch }}