clean_cache.yml

on:
  pull_request:
    branches: 
      - master
    types:
      - closed

jobs:
  clear_cache:
    runs-on: ubuntu-latest
    steps:
      - name: Install and setup mc client
        run: |
          wget https://dl.min.io/client/mc/release/linux-amd64/mc
          chmod +x mc
          ./mc --help
          ./mc alias set hetzner https://hel1.your-objectstorage.com ${{ secrets.HETZNER_S3_ACCESS_KEY }} ${{ secrets.HETZNER_S3_ACCESS_SECRET }}
      
      - name: Remove matching cache objects
        shell: bash
        run: |
          # CAREFUL: only bash, not zsh compatible
          all_objects=$(./mc ls --quiet --recursive hetzner/gha-cache | awk '{ print $6 }')
          filtered=""
          for line in $all_objects; do
            # will match (any_char)<branch_name>(-<any_number>)/cache.tzst, anything inside () being optional
            if [[ "$line" =~ ^.*${{ github.head_ref }}-?[0-9]*?\/cache\.tzst$ ]]; then
              filtered="$line $filtered"
            fi
          done

          for entry in $filtered; do
            ./mc rm --recursive --force hetzner/gha-cache/${entry} || echo "couldn't find $entry"
          done