forkjo/.forgejo/workflows/backport.yml

# Copyright 2024 The Forgejo Authors
# SPDX-License-Identifier: MIT
#
# To modify this workflow:
#
#  - change pull_request_target: to  pull_request:
#    so that it runs from a pull request instead of the default branch
#
#  - push it to the wip-ci-backport branch on the forgejo repository
#    otherwise it will not have access to the secrets required to push
#    the PR
#
#  - open a pull request targetting wip-ci-backport that includes a change
#    that can be backported without conflict in v1.21 and set the
#    `backport/v1.21` label.
#
#  - once it works, open a pull request for the sake of keeping track
#    of the change even if the PR won't run it because it will use
#    whatever is in the default branch instead
#
#  - after it is merged, double check it works by setting a
#    `backport/v1.21` label on a merged pull request that can be backported
#    without conflict.
#
on:
  pull_request_target:
    types:
      - closed
      - labeled

jobs:
  backporting:
    if: >
      !startsWith(vars.ROLE, 'forgejo-') && (
        github.event.pull_request.merged
        && (
          (
            github.event.action == 'closed' &&
            contains(toJSON(github.event.pull_request.labels), 'backport/v')
          )
          ||
          (
            github.event.action == 'labeled' &&
            contains(github.event.label.name, 'backport/v')
          )
        )
      )
    runs-on: docker
    container:
      image: 'docker.io/node:20-bookworm'
    steps:
      - name: Fetch labels
        id: fetch-labels
        shell: bash
        run: |
          set -x
          echo "Labels retrieved below"
          export DEBIAN_FRONTEND=noninteractive
          apt-get update -qq
          apt-get -q install -qq -y jq
          filtered_labels=$(echo "$LABELS" | jq -c 'map(select(.name | startswith("backport/v")))')
          echo "FILTERED_LABELS=${filtered_labels}" >> $GITHUB_ENV
        env:
          LABELS: ${{ toJSON(github.event.pull_request.labels) }}
      - name: Extract targets
        id: extract-targets
        shell: bash
        run: |
          set -x
          targets="$(echo $FILTERED_LABELS | jq -c '[.[] | .name | sub("backport/"; "")]')"
          echo "targets=$(echo $targets)" >> $GITHUB_OUTPUT

      - name: Printing info
        shell: bash
        run: |
          echo "targets: ${{ steps.extract-targets.outputs.targets }}"
          echo "target-branch: ${{ fromJSON(steps.extract-targets.outputs.targets)[0] }}"
          echo "pull-request: ${{ github.event.pull_request.url }}"

      - uses: https://code.forgejo.org/actions/git-backporting@v4.5.2
        with:
          target-branch: ${{ fromJSON(steps.extract-targets.outputs.targets)[0] }}/forgejo
          no-squash: true
          auth: ${{ secrets.BACKPORT_TOKEN }}
          pull-request: ${{ github.event.pull_request.url }}