dependabot_reviewer.yml

# Auto-merge as documented in official Github docs
# https://docs.github.com/en/code-security/dependabot/working-with-dependabot/automating-dependabot-with-github-actions

name: Auto-review Dependabot PRs
on: pull_request_target

permissions:
  pull-requests: write
  contents: write

jobs:
  dependabot-reviewer:
    runs-on: ubuntu-latest

    if: ${{ github.event.pull_request.user.login == 'dependabot[bot]' }}
    
    steps:
      - name: Checkout Repository
        uses: actions/checkout@v2

      - name: Dependabot metadata
        id: metadata
        uses: dependabot/fetch-metadata@v1.5.1
        with:
          github-token: "${{ secrets.GITHUB_TOKEN }}"

      - name: Check Whitelist
        id: check-whitelist
        if: steps.metadata.outputs.update-type == 'version-update:semver-patch' || steps.metadata.outputs.update-type == 'version-update:semver-minor'
        run: |
          cfg_path=".github/workflows/whitelist.json"
        
          IFS=', ' read -r -a libsUpdated <<< "${{ steps.metadata.outputs.dependency-names }}"

          # Loop through the array to make sure all updated libraries are whitelisted
          all_in_whitelist="true"
          reason_array=()

          # If any element is not in the whitelist, set the flag to false
          for lib in "${libsUpdated[@]}"; do
            exists=$(jq --arg lib "$lib" 'any(.[]; .name == $lib)' $cfg_path)
            if [[ "$exists" != "true" ]]; then
              echo "$lib is not in the whitelist, manual review is required."
              all_in_whitelist="false"
              break
            else
              reason_array+=("$(jq -r --arg lib "$lib" '.[] | select(.name == $lib) | .reason' $cfg_path)")
            fi
          done

          if [[ "$all_in_whitelist" == "true" ]]; then
            reasons=$(IFS=','; echo "${reason_array[*]}")
            echo "All dependencies are in the whitelist. with reason $reasons"
            echo "::set-output name=reasons::$reasons"
            echo "::set-output name=allInWhitelist::true"
          else
            echo "Not all dependencies are in the whitelist."
            echo "::set-output name=allInWhitelist::false"
          fi

      - name: Approve and auto-merge
        if: steps.check-whitelist.conclusion == 'success' && steps.check-whitelist.outputs.allInWhitelist == 'true'
        run: |
          gh pr merge --auto --squash "$PR_URL"
          gh pr review $PR_URL \
          --approve -b "**I'm approving** this pull request because it includes a patch or minor \
          update to dependencies that are already whitelisted.

          The reason this library is whitelisted is that ${{ steps.check-whitelist.outputs.reasons}}"
        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}

      - name: Manual review is required
        if: steps.check-whitelist.conclusion != 'success' || steps.check-whitelist.outputs.allInWhitelist == 'false'
        run: |
          gh pr comment $PR_URL --body "**This library is not auto-approved**

          Unfortunately, this library is not included in our whitelist, which means it cannot be auto-approved. \
          If you believe it should be considered for auto-approval, please open a pull request to add \
          it to the whitelist configuration. 

          To add this library to the whitelist, please modify the [whitelist.json](https://https://github.com/grafana/mimir/.github/workflow/whitelist.json) file and \
          include the necessary details for review."

        env:
          PR_URL: ${{github.event.pull_request.html_url}}
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}