sync-with-upstream.yml

name: "Sync with upstream"

on:
  schedule:
    - cron: 20 4 * * *

  workflow_dispatch:


env:
  # repo to fetch changes from
  UPSTREAM_REPO: vllm-project/vllm
 # branch to sync
  BRANCH: main

jobs:
  upstream-sync:
    name: Sync with upstream
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
      contents: write

    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Fetch upstream repo
        run: |
          git remote add upstream https://github.com/${UPSTREAM_REPO}
          git fetch upstream

      - name: Check diff
        id: diff
        shell: bash
        run: |
          echo 'diff<<EOF' >> $GITHUB_OUTPUT
          git diff --stat upstream/${BRANCH} | tee -a >(cat >> $GITHUB_OUTPUT)
          echo 'EOF' >> $GITHUB_OUTPUT

      - name: Create PR
        if: ${{ steps.diff.outputs.diff != '' }}
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          set -xeu

          git_hash="$(git rev-parse upstream/${BRANCH})"
          echo "git_hash=$git_hash" >> $GITHUB_OUTPUT
          git_describe="$(git describe --tags upstream/${BRANCH})"
          echo "git_describe=$git_describe" >> $GITHUB_OUTPUT

          # echo 'commits<<EOF' >> $GITHUB_OUTPUT
          # git log --oneline ..upstream/${BRANCH} >> $GITHUB_OUTPUT
          # echo 'EOF' >> $GITHUB_OUTPUT

          upstream_url="https://github.com/${UPSTREAM_REPO}"
          upstream_branch="$upstream_url/tree/${BRANCH}"

          title="Sync with upstream@${git_describe}"
          body="Merge [${UPSTREAM_REPO}]($upstream_url):[${BRANCH}]($upstream_branch)@[${git_describe}](${upstream_url}/commit/$git_hash) into $BRANCH"

          gh repo set-default $GITHUB_REPOSITORY
          pr_number=$(gh pr list -S "Sync with upstream@" --json number --jq '.[0].number')

          if [[ -z $pr_number ]]; then
            echo "Creating PR"
            gh pr create \
              --head $(echo $UPSTREAM_REPO | sed 's|/|:|g'):${BRANCH} \
              --base ${BRANCH} \
              --label code-sync \
              --title "$title" \
              --body "$body" \
              --draft \
              --no-maintainer-edit
            exit 0
          fi

          echo "Checking if PR is up-to-date"

          git fetch ${upstream_url} refs/pull/${pr_number}/head
          if git diff --stat --exit-code upstream/main FETCH_HEAD; then
            echo "PR is up-to-date"
            exit 0
          fi

          echo "Updating PR \#${pr_number}"
          gh pr edit \
            $pr_number \
            --body "$body" \
            --title "$title"