helm-diff.yaml

name: Generate Helm Diffs for PR

on:
  workflow_dispatch:
    inputs:
      pr_number:
        description: 'PR number to generate diff for'
        required: true
        type: string
  issue_comment:
    types: [created]

jobs:
  helm-diff:
    if: |
      github.event_name == 'workflow_dispatch' ||
      (github.event.issue.pull_request && contains(github.event.comment.body, '/helm-diff'))
    runs-on: ubuntu-latest
    steps:
      - name: Checkout PR Code
        uses: actions/checkout@v4
        with:
          ref: refs/pull/${{ github.event_name == 'workflow_dispatch' ? inputs.pr_number : github.event.issue.number }}/head

      - name: Set up Helm
        uses: azure/setup-helm@v1
        with:
          version: '3.10.2'

      - name: Install Helm Diff Plugin
        run: helm plugin install https://github.com/databus23/helm-diff

      - name: Add Helm Repositories
        run: |
          helm repo add bitnami https://charts.bitnami.com/bitnami
          helm repo add bitnami-labs https://bitnami-labs.github.io/sealed-secrets/
          helm repo add cert-manager https://charts.jetstack.io
          helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
          helm repo add metallb https://metallb.github.io/metallb
          helm repo add oauth2-proxy https://oauth2-proxy.github.io/manifests
          helm repo update

      - name: Set up kubeconfig
        run: |
          mkdir -p ~/.kube
          echo "${{ secrets.HELM_DIFF_KUBECONFIG }}" > ~/.kube/config
          chmod 600 ~/.kube/config

      - name: Generate and Format Diffs
        id: generate-diff
        run: |
          # Create header for the diff output file
          echo "### Helm Diff Results" > diff_output.md
          echo "" >> diff_output.md
          
          # Function to process diff output and wrap each resource in a dropdown
          process_diff() {
            local resource=""
            local diff_content=""
            local in_diff=false

            while IFS= read -r line; do
              if [[ $line =~ ^"bt, "* ]]; then
                # If a new resource is found, output the previous one (if exists)
                if [ -n "$resource" ]; then
                  {
                    echo "<details>"
                    echo "<summary>$resource</summary>"
                    echo ""
                    echo "\`\`\`diff"
                    echo "$diff_content"
                    echo "\`\`\`"
                    echo "</details>"
                    echo ""
                  } >> diff_output.md
                fi
                # Start a new resource block
                resource="${line#bt, }"
                diff_content=""
                in_diff=true
              elif [ "$in_diff" = true ]; then
                diff_content+="$line"$'\n'
              fi
            done

            # Output the last resource block if exists
            if [ -n "$resource" ]; then
              {
                echo "<details>"
                echo "<summary>$resource</summary>"
                echo ""
                echo "\`\`\`diff"
                echo "$diff_content"
                echo "\`\`\`"
                echo "</details>"
                echo ""
              } >> diff_output.md
            fi
          }
          
          # Update chart dependencies if needed
          helm dependency update ./infra/app
          helm dependency update ./infra/base
          
          # Process app chart diff output and log raw diff
          echo "#### App Chart Changes" >> diff_output.md
          echo "" >> diff_output.md
          echo "Raw App Chart Diff:" >> /tmp/raw_diffs.log
          helm diff upgrade bt-prod-app ./infra/app \
            --install \
            --namespace=bt \
            --set host=stanfurdtime.com \
            --version 1.0.0 2>&1 | tee -a /tmp/raw_diffs.log | process_diff
          
          # Process base chart diff output and log raw diff
          echo "" >> diff_output.md
          echo "#### Base Chart Changes" >> diff_output.md
          echo "" >> diff_output.md
          echo "Raw Base Chart Diff:" >> /tmp/raw_diffs.log
          helm diff upgrade bt-base ./infra/base \
            --install \
            --namespace=bt \
            --version 1.0.0 2>&1 | tee -a /tmp/raw_diffs.log | process_diff

          # Add a dropdown for the raw diff output
          echo "" >> diff_output.md
          echo "#### 📋 Raw Helm Diff Output" >> diff_output.md
          echo "<details>" >> diff_output.md
          echo "" >> diff_output.md
          echo "\`\`\`" >> diff_output.md
          cat /tmp/raw_diffs.log >> diff_output.md
          echo "\`\`\`" >> diff_output.md
          echo "</details>" >> diff_output.md
          
          # Log the raw diffs to GitHub Actions output
          echo "raw_diffs<<EOF" >> $GITHUB_OUTPUT
          cat /tmp/raw_diffs.log >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT
          
          # Save the formatted diff output as a step output using a unique delimiter
          delim=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
          echo "diff<<$delim" >> $GITHUB_OUTPUT
          cat diff_output.md >> $GITHUB_OUTPUT
          echo "$delim" >> $GITHUB_OUTPUT

      - name: Log Raw Diffs
        run: |
          echo "Raw Helm Diffs:"
          echo "${{ steps.generate-diff.outputs.raw_diffs }}"

      - name: Comment PR with Diff Output
        uses: actions/github-script@v6
        with:
          script: |
            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: Number(process.env.PR_NUMBER),
              body: process.env.DIFF
            });
        env:
          PR_NUMBER: ${{ inputs.pr_number }}
          DIFF: ${{ steps.generate-diff.outputs.diff }}