enforce-toolchain-synchronization.yml

# Enforce rebasing Pull Requests if Toolchain was modified on target branch
#
# If new commits, which modifies toolchain files was pushed to given branch, find all PRs targeting
# this branch, which also change toolchain files. Then, enforce rebasing them by changing
# CI/Jenkins/toolchain check to FAILURE.
# This prevents race condition issue when new toolchain bundle has to be built after PR is merged.
#
# Toolchain files:
# * scripts/requirements-fixed.txt
# * scripts/tools-versions-darwin.yml
# * scripts/tools-versions-win10.yml
# * scripts/tools-versions-linux.yml

name: Enforce rebasing Pull Requests if Toolchain was modified on target branch

on:
  push:
    branches:
      - '**'  # Triggers on pushes to any branch
jobs:
  check-prs:
    if: ${{ !github.event.created }}  # Skip for new branches
    runs-on: ubuntu-latest

    steps:
      - name: Define list of files to check
        id: define_files
        run: |
          echo "TOOLCHAIN_FILES=scripts/requirements-fixed.txt,scripts/tools-versions-linux.yml,scripts/tools-versions-darwin.yml,scripts/tools-versions-win10.yml" >> $GITHUB_ENV

      - name: Checkout the repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          persist-credentials: false

      - name: Get files modified by recent commits
        id: get_files
        run: |
          echo "Modified files in this commit:"
          git diff --name-only ${{ github.event.before }} ${{ github.sha }} > modified_files.txt
          cat modified_files.txt

      - name: Check if any watched files are modified
        id: check_files
        run: |
          modified_files=$(cat modified_files.txt)
          IFS=',' read -r -a watched_files <<< "${{ env.TOOLCHAIN_FILES }}"
          modified=false
          for file in "${watched_files[@]}"; do
            if echo "$modified_files" | grep -q "$file"; then
              echo "$file was modified."
              modified=true
            fi
          done
          echo "modified=$modified" >> $GITHUB_ENV

      # App token is required to update Check Status
      - name: Get jenkins-ncs App token
        if: env.modified == 'true'
        uses: actions/create-github-app-token@v1
        id: app-token
        with:
          app-id: ${{ vars.JENKINS_NCS_APP_ID }}
          private-key: ${{ secrets.JENKINS_NCS_APP_PRIVATE_KEY }}

      - name: Find open pull requests targeting this branch and modyfing Toolchain files
        if: env.modified == 'true'
        id: find_prs
        run: |
          PRs=$(gh pr list --base ${{ github.ref_name }} --state open --json url,headRefName,files --jq '[.[] | select(.files[]? | .path as $file | [$file] | inside([env.TOOLCHAIN_FILES]))]')
          echo "Found PRs: $PRs"
          echo "prs=$PRs" >> $GITHUB_ENV
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}

      - name: Set CI/Jenkins/toolchain status check to failure
        if: env.modified == 'true' && steps.find_prs.outputs.prs != '[]'
        env:
          GH_TOKEN: ${{ steps.app-token.outputs.token }}
        run: |
          for pr in $(echo "$prs" | jq -r '.[].url'); do
            pr_url=$(echo $pr | sed 's|https://github.com/||')
            pr_owner=$(echo $pr_url | cut -d'/' -f1)
            pr_repo=$(echo $pr_url | cut -d'/' -f2)
            pr_number=$(echo $pr_url | cut -d'/' -f4)

            echo "Setting CI/Jenkins/toolchain status to failure for PR: $pr"

            # Get the SHA of the last commit in the PR branch
            commit_sha=$(gh pr view $pr_number --json headRefOid --jq '.headRefOid')

            # Get the Check Run ID by listing the check runs for the PR's head commit
            check_run_id=$(gh api \
              -H "Accept: application/vnd.github.v3+json" \
              /repos/$pr_owner/$pr_repo/commits/$commit_sha/check-runs \
              --jq '.check_runs[] | select(.name == "CI/Jenkins/toolchain") | .id')

            # If no check run exists, create a new one; otherwise, update the existing one
            if [ -z "$check_run_id" ]; then
              echo "Creating new check run for PR: $pr"
              gh api \
                -H "Accept: application/vnd.github.v3+json" \
                --method POST /repos/$pr_owner/$pr_repo/check-runs \
                -f name="CI/Jenkins/toolchain" \
                -f head_sha="$commit_sha" \
                -f status="completed" \
                -f conclusion="failure" \
                -f output[title]="Rebase needed - Toolchain changed on '${{ github.ref_name }}' branch" \
                -f output[summary]="Toolchain was modified on '${{ github.ref_name }}' and this PR has to be rebased"
            else
              echo "Updating existing check run with ID $check_run_id"
              gh api \
                -H "Accept: application/vnd.github.v3+json" \
                --method PATCH /repos/$pr_owner/$pr_repo/check-runs/$check_run_id \
                -f conclusion="failure" \
                -f status="completed" \
                -f output[title]="Rebase needed - Toolchain changed on '${{ github.ref_name }}' branch" \
                -f output[summary]="Toolchain was modified on '${{ github.ref_name }}' and this PR has to be rebased"
            fi
          done