backport-pr.yml

name: Link-Backport-PR-Issue

on:
  pull_request:
    types: [opened]
    branches:
      - master
      - "v*"

jobs:
  check-backport:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Check if PR is a backport
        run: |
          if [[ "${{ github.event.pull_request.title }}" =~ "backport #" ]]; then
            echo "BACKPORT=true" >> $GITHUB_ENV
          else
            echo "BACKPORT=false" >> $GITHUB_ENV
          fi

      - name: Extract backport branch and issue number
        if: env.BACKPORT == 'true'
        run: |
          # Extract branch from the target branch of the PR
          BRANCH=$(echo "${{ github.event.pull_request.base.ref }}")
          BRANCH=${BRANCH%.x}   # Remove the '.x' suffix
          BRANCH=$(echo "${BRANCH}" | sed 's/\./\\./g')   # Escape periods
          echo "BRANCH=$BRANCH" >> $GITHUB_ENV

          # Extract issue number from the PR description
          ORIGINAL_ISSUE_NUMBER=$(echo "${{ github.event.pull_request.body }}" | grep -oE 'issues/[0-9]+' | cut -d'/' -f2)
          echo "ORIGINAL_ISSUE_NUMBER=$ORIGINAL_ISSUE_NUMBER" >> $GITHUB_ENV

      - name: Get the original issue
        if: env.BACKPORT == 'true'
        id: original-issue
        uses: octokit/request-action@v2.x
        with:
          route: GET /repos/longhorn/longhorn/issues/${{ env.ORIGINAL_ISSUE_NUMBER }}
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: URL encode the original issue title
        if: env.BACKPORT == 'true'
        run: echo "ORIGINAL_ISSUE_TITLE=$(node -e 'console.log(encodeURIComponent("${{ fromJson(steps.original-issue.outputs.data).title  }}"))')" >> $GITHUB_ENV

      - name: Find corresponding backport issue number
        if: env.BACKPORT == 'true'
        run: |
          BACKPORT_ISSUE_NUMBER=$(curl -s "https://api.github.com/search/issues?q=repo:longhorn/longhorn+is:open+is:issue+in:title+${{ env.BRANCH }}+${{ env.ORIGINAL_ISSUE_TITLE }}" | jq .items[0].number)
          echo "BACKPORT_ISSUE_NUMBER=$BACKPORT_ISSUE_NUMBER" >> $GITHUB_ENV

      - name: Link the PR with the corresponding backport issue
        if: env.BACKPORT == 'true'
        run: |
          # Relate the pull request to the backport issue
          gh issue comment --repo longhorn/longhorn ${{ env.BACKPORT_ISSUE_NUMBER }} --body "Related PR: ${{ github.event.pull_request.html_url }}"
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}