cherrypick.yml

# Copyright lowRISC contributors (OpenTitan project).
# Licensed under the Apache License, Version 2.0, see LICENSE for details.
# SPDX-License-Identifier: Apache-2.0

name: Cherry-pick Pull Request
on:
  pull_request_target:
    types: [closed, labeled]

permissions:
  contents: read

# 2 backport jobs may be running simultaneously if the merge and label event happen in quick
# succession. Serialize them based on PR number to avoid this.
concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: false

jobs:
  cherrypick:
    # NOTE: We currently need these permissions because we create pull request with the repo-scoped
    # default token. We should in the future move to a PAT owned by lowrisc-bot and create pull request
    # on its behalf.
    permissions:
      # Needed for the action to create branch.
      contents: write
      # Needed for the action to create a pull request.
      pull-requests: write

    name: Cherry-pick Pull Request
    if: github.event.pull_request.merged == true && (github.event_name != 'labeled' || startsWith('CherryPick:', github.event.label.name))
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Create backport PRs
        id: backport
        uses: korthout/backport-action@e8161d6a0dbfa2651b7daa76cbb75bc7c925bbf3 # v2.4.1
        with:
          label_pattern: "^CherryPick:([^ ]+)$"
          pull_title: "Cherry-pick to ${target_branch}: ${pull_title}"
          pull_description: |
            This is an automatic cherry-pick of #${pull_number} to branch `${target_branch}`.

      - name: Apply label for manually cherry picking
        if: ${{ steps.backport.outputs.was_successful == 'false' }}
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          gh pr edit ${{ github.event.pull_request.number }} --add-label 'Manually CherryPick'