docker-registry.helm/.github/workflows/pr_diff.yaml

name: PR Diff for Helm chart
on:
  pull_request:

jobs:
  diff:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: azure/setup-helm@v3
      - name: Run diff
        id: diff
        run: |
          OPTIONS=(
            --set serviceAccount.create=true
            --set priorityClassName=high
            --set podAnnotations.test=annotation
            --set extraEnvVars[0].name=TEST_NAME
            --set extraEnvVars[0].value=TEST_VALUE
            --set secrets.htpasswd=abc
            --set tlsSecretName=abc
            --set garbageCollect.enabled=true
            --set proxy.enabled=true
            --set storage=s3
            --set secrets.s3.secretKey=abc
            --set secrets.s3.accessKey=def
            --set s3.region=us-42
            --set s3.bucket=abc
            --set s3.encrypt=abc
          )
          # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#multiline-strings
          echo 'HELM_DIFF<<EOF' >> $GITHUB_ENV
          diff -u <(helm template --debug ${OPTIONS[@]} ${{ github.server_url }}/${{ github.repository }}/archive/refs/heads/${{ github.base_ref }}.tar.gz) <(helm template --debug ${OPTIONS[@]} .) >> $GITHUB_ENV
          echo 'EOF' >> $GITHUB_ENV
      - uses: marocchino/sticky-pull-request-comment@v2
        with:
          message: |
            Running a `helm template` smoketest on this branch results in the following diff against `${{ github.base_ref }}`:
            
            ```diff
            ${{ env.HELM_DIFF }}
            ```