cleanup-cache-postpr.yml

name: CleanUpCachePostPR

on:
  workflow_run:
    workflows: [PostPR]
    types:
      - completed

jobs:
  CleanUpCcacheCachePostPR:
    name: Clean Up Ccache Cache Post PR
    runs-on: ubuntu-22.04
    permissions:
      actions: write
      contents: read
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
      - uses: actions/checkout@v4
      - name: Clean up ccache
        run: |
          gh extension install actions/gh-actions-cache

          REPO=${{ github.repository }}

          # For debugging cat ${GITHUB_EVENT_PATH} to see the payload.

          pr_head_sha=${{ github.event.workflow_run.head_sha }}
          pr_number=$(gh pr list --state all --search $pr_head_sha --json number --jq '.[0].number')
          echo "Post-PR cache cleanup for PR ${pr_number}"
          BRANCH=refs/pull/${pr_number}/merge

          # Setting this to not fail the workflow while deleting cache keys.
          set +e

          keys=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH | cut -f 1)
          # $keys might contain spaces. Thus we set IFS to \n.
          IFS=$'\n'
          for k in $keys
          do
            gh actions-cache delete "$k" -R $REPO -B $BRANCH --confirm
          done
          unset IFS