automerge.yaml

---
name: automerge
on:
  workflow_run:
    types:
      - completed
    workflows:
      - "ci"
jobs:
  automerge:
    name: Automerge
    runs-on: ubuntu-latest
    if: ${{ github.event.workflow_run.conclusion == 'success' && github.actor == 'nsmbot' }}
    outputs:
      pr_branch_ref: ${{ steps.check_mergeability.outputs.pr_branch_ref }}
    steps:
      - name: Find current PR
        uses: jwalton/gh-find-current-pr@v1.0.2
        id: findPr
        with:
          sha: ${{ github.event.workflow_run.head_sha }}
          github-token: ${{ secrets.NSM_BOT_GITHUB_TOKEN }}
      - name: Validate PR number
        run: |
          if [ -z ${{ steps.findPr.outputs.pr }} ]; then
            echo "No opened PR was found for SHA ${{ github.event.workflow_run.head_sha }}"
            exit 1
          fi
      - name: Get PR Info
        id: get_pull_request_info
        uses: octokit/request-action@v2.x
        with:
          route: GET /repos/${{ github.repository }}/pulls/${{ steps.findPr.outputs.pr }}
        env:
          GITHUB_TOKEN: ${{ secrets.NSM_BOT_GITHUB_TOKEN }}
      - name: Check mergeability
        id: check_mergeability
        run: |
          echo "Mergeable: ${{ fromJson(steps.get_pull_request_info.outputs.data).mergeable }}"
          PR_BRANCH_REF=${{ fromJson(steps.get_pull_request_info.outputs.data).head.ref }}
          echo "PR_BRANCH_REF: $PR_BRANCH_REF"
          echo "::set-output name=pr_branch_ref::$PR_BRANCH_REF"
          if [ "${{ fromJson(steps.get_pull_request_info.outputs.data).mergeable }}" != "true" ]; then
            echo "PR has conflicts"
            exit 1
          fi
      - name: Check out the code
        uses: actions/checkout@v2
      - name: Fetch main
        run: |
          git remote -v
          git fetch --depth=1 origin main
      - name: Only allow go.mod and go.sum changes
        run: |
          find . -type f ! -name 'go.mod' ! -name 'go.sum' ! -name '*.yaml' ! -name '*.yml' ! -name '*.txt' ! -name '*.md' ! -name '*.conf' -exec git diff --exit-code origin/main -- {} +
      - name: Merge PR
        uses: ridedott/merge-me-action@master
        with:
          GITHUB_LOGIN: nsmbot
          ENABLED_FOR_MANUAL_CHANGES: true
          GITHUB_TOKEN: ${{ secrets.NSM_BOT_GITHUB_TOKEN }}
  resolve_conflicts:
    name: Autoresolve Conflicts
    needs: [automerge]
    if: ${{ always() && needs.automerge.result == 'failure' && needs.automerge.outputs.pr_branch_ref != '' && github.actor == 'nsmbot' }}
    runs-on: ubuntu-latest
    steps:
      - name: Checkout default branch
        uses: actions/checkout@v2
        with:
          fetch-depth: 0
          token: ${{ secrets.NSM_BOT_GITHUB_TOKEN }}
      - name: Checkout PR branch
        uses: actions/checkout@v2
        with:
          ref: ${{ needs.automerge.outputs.pr_branch_ref }}
          fetch-depth: 0
          token: ${{ secrets.NSM_BOT_GITHUB_TOKEN }}
      - name: Verify conflicts only in go.mod/go.sum
        run: |
          CONFLICTING_FILES=$(git merge-tree $(git merge-base origin/main HEAD) origin/main HEAD | \
            awk 'BEGIN {is_conflict = 0} /changed in both/{is_conflict = 1; next} /base/{if (is_conflict) {print $4; is_conflict = 0} next }' | \
            { grep -vF "go.mod" || true; } | \
            { grep -vF "go.sum" || true; })
          if [[ -n $CONFLICTING_FILES ]]; then
            echo "Conflicts can be resolved only in go.mod and go.sum files, but conflicts were found in other files: $CONFLICTING_FILES"
            exit 1
          fi
      - name: Check number of retries
        run: |
          if [ $(git log --oneline | head -n 10 | grep -Fc "Automatically resolving conflicts in go.mod") -ge 3 ]; then
            echo "Couldn't automatically resolve conflicts (number of re-tries is >= 3). Please, resolve them manually."
            exit 1
          fi
      - name: Merge default branch
        run: |
          git config --global user.email "nsmbot@networkservicmesh.io"
          git config --global user.name "NSMBot"
          git config pull.rebase false
          git pull -q origin main -s ort -X theirs
      - name: Setup Go
        uses: actions/setup-go@v1
        with:
          go-version: 1.16
      - name: Re-generate go.sum
        run: go mod tidy
      - name: Push changes
        run: |
          echo "Automatically resolving conflicts in go.mod and updating dependency versions to the latest" >> /tmp/commit-message
          git config --global user.email "nsmbot@networkservicmesh.io"
          git config --global user.name "NSMBot"
          git add -- go.sum go.mod
          git commit -s -F /tmp/commit-message
          echo "Force-pushing changes to ${{ needs.automerge.outputs.pr_branch_ref }}"
          git push -f origin ${{ needs.automerge.outputs.pr_branch_ref }}