backport.yaml

name: backport
on:
  pull_request_target:
    types:
      - closed
      - labeled

jobs:
  backport:
    runs-on: ubuntu-latest
    # Only react to merged PRs for security reasons.
    # See https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#pull_request_target.
    if: >
      github.event.pull_request.merged
      && (
        github.event.action == 'closed'
        || (
          github.event.action == 'labeled'
          && contains(github.event.label.name, 'backport')
        )
      )
    steps:
      - name: Generate token
        id: generate-token
        uses: tibdex/github-app-token@v2
        with:
          app_id: ${{ secrets.APP_ID }}
          private_key: ${{ secrets.PRIVATE_KEY }}

      - uses: tibdex/backport@v2
        with:
          github_token: ${{ steps.generate-token.outputs.token }}
          title_template: "<%= title %> (backport #<%= number %>)"