.github/workflows/automatic-backport.yml

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#
---
name: Automatic Backport
on:  # yamllint disable-line rule:truthy
  push:
    branches:
      - main
permissions:
  contents: read
jobs:
  get-pr-info:
    name: "Get PR information"
    runs-on: ubuntu-latest
    outputs:
      branches: ${{ steps.pr-info.outputs.branches }}
      commit-sha: ${{ github.sha }}
    steps:
      - name: Get commit SHA
        id: get-sha
        run: echo "COMMIT_SHA=${GITHUB_SHA}" >> $GITHUB_ENV

      # Adding a slight delay to allow GitHub's API to associate the merge commit with the PR.
      # This is needed because GH has a consistency of 6-10+ seconds
      # to process the commit and PR association after a merge based on some of our past runs.
      # Without this delay, the listPullRequestsAssociatedWithCommit API call may return an empty array
      # even though a PR was just merged, causing backports to be skipped.
      - name: Add delay for GitHub to process PR merge
        run: sleep 15

      - name: Find PR information
        id: pr-info
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea  # v7.0.1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          script: |
            const { data: pullRequest } = await github.rest.repos.listPullRequestsAssociatedWithCommit({
                owner: context.repo.owner,
                repo: context.repo.repo,
                commit_sha: process.env.GITHUB_SHA
            });
            if (pullRequest.length > 0) {
                const pr = pullRequest[0];
                const backportBranches = pr.labels
                      .filter(label => label.name.startsWith('backport-to-'))
                      .map(label => label.name.replace('backport-to-', ''));

                console.log(`Commit ${process.env.GITHUB_SHA} is associated with PR ${pr.number}`);
                console.log(`Backport branches: ${backportBranches}`);
                core.setOutput('branches', JSON.stringify(backportBranches));
            } else {
                console.log('⚠️ No pull request found for this commit.');
                core.setOutput('branches', '[]');
            }

  trigger-backport:
    name: "Trigger Backport"
    uses: ./.github/workflows/backport-cli.yml
    needs: get-pr-info
    if: ${{ needs.get-pr-info.outputs.branches != '[]' }}
    strategy:
      matrix:
        branch: ${{ fromJSON(needs.get-pr-info.outputs.branches) }}
      fail-fast: false
    permissions:
      contents: write
      pull-requests: write
    with:
      target-branch: ${{ matrix.branch }}
      commit-sha: ${{ needs.get-pr-info.outputs.commit-sha }}