cleanup-cache.yml

name: CleanUpCache

on:
  workflow_run:
    workflows: [bittree, LinuxClang, cuda, LinuxGcc, hip, Hypre, intel, macos, PETSc, SUNDIALS, CodeQL, smoke, apps]
    types:
      - completed

jobs:
  CleanUpCcacheCache:
    name: Clean Up Ccache Cache for ${{ github.event.workflow_run.name }}
    runs-on: ubuntu-latest
    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 }}

          # push or pull_request or schedule or ...
          EVENT=${{ github.event.workflow_run.event }}

          # Triggering workflow run name (e.g., LinuxClang)
          WORKFLOW_NAME="${{ github.event.workflow_run.name }}"

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

          if [[ $EVENT == "pull_request" ]]; then
            pr_head_sha=${{ github.event.workflow_run.head_sha }}
            pr_number=$(gh pr list --search $pr_head_sha --json number --jq '.[0].number')
            echo "Clean up cache for PR ${pr_number}"
            BRANCH=refs/pull/${pr_number}/merge
          else
            BRANCH=refs/heads/${{ github.event.workflow_run.head_branch }}
          fi

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

          # In our cache keys, substring after `-git-` is git hash, substring
          # before that is a unique id for jobs (e.g., `ccache-LinuxClang-configure-2d`).
          # The goal is to keep the last used key of each job and delete all others.

          # something like ccache-LinuxClang-
          keyprefix="ccache-${WORKFLOW_NAME}-"

          cached_jobs=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH --key "$keyprefix" | awk -F '-git-' '{print $1}' | sort | uniq)

          # cached_jobs is something like "ccache-LinuxClang-configure-1d ccache-LinuxClang-configure-2d".
          # It might also contain spaces. Thus we set IFS to \n.
          IFS=$'\n'
          for j in $cached_jobs
          do
            # Delete all entries except the last used one
            old_keys=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH --key "${j}-git-" --sort last-used | cut -f 1 | tail -n +2)
            for k in $old_keys
            do
              gh actions-cache delete "$k" -R $REPO -B $BRANCH --confirm
            done
          done
          unset IFS