auto-backport.yml

name: Auto-backport
on:
  pull_request:
    types: [closed, labeled]

jobs:
  create-backport:
    if: github.event.pull_request.merged == true && (contains(github.event.pull_request.labels.*.name, 'backport') && github.event.action == 'closed' || github.event.label.name == 'backport')
    runs-on: ubuntu-22.04
    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 0
      - uses: tibdex/github-app-token@v1.6.0
        id: generate-token
        with:
          app_id: ${{ secrets.METABASE_BOT_APP_ID }}
          private_key: ${{ secrets.METABASE_BOT_APP_PRIVATE_KEY }}
      - uses: ./.github/actions/find-squashed-commit
        name: Find commit
        id: find_commit
        with:
          pull-request-number: ${{ github.event.pull_request.number }}
          base-ref: ${{ github.event.pull_request.base.ref }}

      - uses: ./.github/actions/get-latest-release-branch
        name: Get latest release branch
        id: get_latest_release_branch

      - id: create_backport_pull_request
        name: Create backport pull request
        run: |
          git config --global user.email "metabase-bot@metabase.com"
          git config --global user.name "Metabase bot"

          BACKPORT_BRANCH="backport-$COMMIT"

          git checkout ${TARGET_BRANCH}
          git fetch --all
          git checkout -b ${BACKPORT_BRANCH}
          git cherry-pick ${COMMIT} || true

          CONFLICTS=$(git ls-files -u | wc -l)
          if [ "$CONFLICTS" -gt 0 ]; then
            echo "Could not cherry pick because of a conflict"
            echo "has-conflicts=true" >> $GITHUB_OUTPUT
            git cherry-pick --abort
            git checkout master
            exit 0
          fi

          echo "has-conflicts=false" >> $GITHUB_OUTPUT

          git checkout master
          git push -u origin ${BACKPORT_BRANCH}

          BACKPORT_PR_URL=$(hub pull-request -b "${TARGET_BRANCH}" -h "${BACKPORT_BRANCH}" -l "was-backported" -a "${GITHUB_ACTOR}" -F- <<<"🤖 backported \"${ORIGINAL_TITLE}\"

          #${ORIGINAL_PULL_REQUEST_NUMBER}")

          BACKPORT_PR_NUMBER=${BACKPORT_PR_URL##*/}

          echo "backport_pr_number=$BACKPORT_PR_NUMBER" >> $GITHUB_OUTPUT
        env:
          TARGET_BRANCH: ${{ steps.get_latest_release_branch.outputs.branch-name }}
          ORIGINAL_PULL_REQUEST_NUMBER: ${{ github.event.pull_request.number }}
          ORIGINAL_TITLE: ${{ github.event.pull_request.title }}
          GITHUB_TOKEN: ${{ steps.generate-token.outputs.token }}
          COMMIT: ${{ steps.find_commit.outputs.commit }}

      - name: Auto approve backport PR
        if: ${{ steps.create_backport_pull_request.outputs.has-conflicts == 'false' }}
        uses: juliangruber/approve-pull-request-action@v1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          number: ${{ steps.create_backport_pull_request.outputs.backport_pr_number }}

      - name: Enable Pull Request Automerge
        if: ${{ steps.create_backport_pull_request.outputs.has-conflicts == 'false' }}
        uses: peter-evans/enable-pull-request-automerge@v2
        with:
          token: ${{ steps.generate-token.outputs.token }}
          pull-request-number: ${{ steps.create_backport_pull_request.outputs.backport_pr_number }}
          merge-method: squash

      - uses: ./.github/actions/notify-pull-request
        if: ${{ steps.create_backport_pull_request.outputs.has-conflicts == 'true' }}
        with:
          include-log: false
          message: could not create a backport due to conflicts

      - uses: ./.github/actions/notify-pull-request
        if: ${{ failure() }}
        with:
          include-log: true
          message: something went wrong while creating a backport