pr-commit-signatures.yml

name: "Commit signatures"

on:
  pull_request:

jobs:
  check:
    runs-on: ubuntu-latest

    steps:
      - name: Fetch commits
        run: gh api "${{ github.event.pull_request._links.commits.href }}" | tee commits.json
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Filter unverified commits
        run: jq '[.[].commit | select(.verification.verified == false)]' < commits.json | tee unverified-commits.json

      - name: List unverified commits
        run: jq '.[] | [{message, tree, author, committer, verification}]' < unverified-commits.json

      - name: Result
        run: |
          COUNT="$(jq '. | length' < unverified-commits.json)"

          if [[ "$COUNT" == "0" ]];
          then
            echo "✅ All commits are verified."
            exit 0
          fi

          echo "❌ PR contains $COUNT unverified commit(s)!"
          echo ""
          echo "Please note that we require that all commits are signed."
          echo "Please see the documentation about signed commits and how to sign yours on GitHub:"
          echo "- https://docs.github.com/en/authentication/managing-commit-signature-verification/about-commit-signature-verification"
          echo "- https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits"
          echo ''
          echo 'Once you have set up commit signatures, you can sign your existing commits:'
          echo ''
          echo '  git rebase main --exec "git commit --amend --gpg-sign --no-edit"'
          echo ''
          echo 'Then you will need to force-push your branch once:'
          echo ''
          echo '  git push --force'
          echo ''
          exit 1