check-chart-versions-bump.yml

name: Check chart version bump
on:
  pull_request:
    paths:
      - 'charts/**'
jobs:
  check_version_bump_on_modified_charts:
    runs-on: ubuntu-latest
    name: Check version bump on modified charts
    steps:
      - uses: actions/checkout@v3
      - id: list_modified_charts
        name: List modified charts
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          # Retrieve the list of modified chart names in the pull request
          modifiedCharts=$(gh pr view ${{ github.event.pull_request.number }} --json files -q '.files[].path' | xargs dirname | grep "^charts/" | cut -d "/" -f 2 | sort --unique | tr '\n' ',')

          # Remove last comma
          modifiedCharts="${modifiedCharts%,}"

          if [ -z "$modifiedCharts" ]; then
            echo "= Info: no modified chart found."
          else
            echo "= modified chart(s): ${modifiedCharts}"
          fi

          # Store the result
          echo "modified_charts=${modifiedCharts}" >> "$GITHUB_OUTPUT"
      - id: check_bump
        if: steps.list_modified_charts.outputs.modified_charts != ''
        name: Check if chart version has been bumped
        run: |
          git fetch --quiet origin pull/${{ github.event.pull_request.number }}/head:pr-branch
          git fetch --quiet origin ${{ github.event.pull_request.base.ref }}:target-branch

          # Set IFS to a comma to split the string into an array
          IFS=',' read -ra chartNames <<< "${{ steps.list_modified_charts.outputs.modified_charts }}"

          notBumped=0

          for chartName in "${chartNames[@]}"; do          
            # Retrieve version from each branch Chart.yaml, or empty if it does not exist
            MAIN_CHART_VERSION=$(git show target-branch:charts/$chartName/Chart.yaml 2>/dev/null | grep "^version:" | cut -d " " -f 2)
            PR_CHART_VERSION=$(git show pr-branch:charts/$chartName/Chart.yaml 2>/dev/null | grep "^version:" | cut -d " " -f 2)

            # If it's a new chart we're just informing the file doesn't exist or a version can't be read from it on the target branch
            if [ -z "$MAIN_CHART_VERSION" ]; then
              echo "= Info: charts/$chartName/Chart.yaml doesn't exist or a version can't be read from it on the target branch."
            fi

            # If the version hasn't been bumped between the pull request and the target branch
            # or if there is no Chart.yaml in the pull request branch
            if [ "$MAIN_CHART_VERSION" == "$PR_CHART_VERSION" ] || [ -z "$PR_CHART_VERSION" ]; then
              echo "= ERROR: the version of the '$chartName' chart hasn't been bumped: '$PR_CHART_VERSION'."
              ((notBumped++))
            fi

            echo "= Info: the version of the '$chartName' chart has been bumped from '$MAIN_CHART_VERSION' to '$PR_CHART_VERSION'."
          done

          if [ "$notBumped" -gt 0 ]; then
            echo "= ERROR: there is at least a version of a chart that hasn't been bumped."
            exit 1
          fi