preview-deploy.yml

# Workflow for building and deploying Hugo PR previews to GitHub Pages
name: preview-deploy

on:
  pull_request_target:
    branches: [ "master" ]
    types: [opened, synchronize, reopened, closed]

  workflow_dispatch:

# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages and comments
permissions:
  contents: write
  pages: write
  pull-requests: write

concurrency:
  group: "pages-${{ github.event.pull_request.number || github.run_id }}"
  cancel-in-progress: true

# Default to bash
defaults:
  run:
    shell: bash

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest
    env:
      HUGO_VERSION: 0.158.0
      PREVIEW_RETENTION_LIMIT: 6

    steps:
      - name: Install Hugo CLI
        if: github.event.action != 'closed'
        run: |
          wget -O ${{ runner.temp }}/hugo.deb https://github.com/gohugoio/hugo/releases/download/v${HUGO_VERSION}/hugo_extended_${HUGO_VERSION}_linux-amd64.deb \
          && sudo dpkg -i ${{ runner.temp }}/hugo.deb

      - name: Install Dart Sass
        if: github.event.action != 'closed'
        run: sudo snap install dart-sass

      - name: Checkout
        if: github.event.action != 'closed'
        uses: actions/checkout@v6
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          submodules: recursive
          fetch-depth: 0
          
      - name: Checkout for cleanup
        if: github.event.action == 'closed'
        uses: actions/checkout@v6
        with:
          ref: gh-pages
          fetch-depth: 0

      - name: Install Node.js dependencies
        if: github.event.action != 'closed'
        run: "[[ -f package-lock.json || -f npm-shrinkwrap.json ]] && npm ci || true"

      - name: Build with Hugo
        if: github.event.action != 'closed'
        env:
          HUGO_ENVIRONMENT: production
          HUGO_ENV: production
        run: |
          REPO_NAME=$(echo "${{ github.repository }}" | cut -d'/' -f2)
          ORG_NAME=$(echo "${{ github.repository }}" | cut -d'/' -f1)

          PR_BASE_URL="https://${ORG_NAME}.github.io/${REPO_NAME}/pr-preview/pr-${{ github.event.pull_request.number }}/"

          echo "Building for BaseURL: ${PR_BASE_URL}"

          hugo \
            --gc \
            --minify \
            --buildDrafts \
            --buildFuture \
            --baseURL "${PR_BASE_URL}"

      - name: Deploy PR Preview
        if: github.event.action != 'closed'
        id: deploy-preview
        uses: rossjrw/pr-preview-action@v1.6.3
        with:
          source-dir: ./public
          preview-branch: gh-pages
          umbrella-dir: pr-preview
          action: auto
          comment: false

      - name: Checkout gh-pages for preview retention
        if: github.event.action != 'closed'
        uses: actions/checkout@v6
        with:
          ref: gh-pages
          fetch-depth: 0
          filter: blob:none
          sparse-checkout: |
            pr-preview
          path: gh-pages-maintenance

      - name: Prune old PR previews
        id: prune-previews
        if: github.event.action != 'closed'
        run: |
          cd gh-pages-maintenance
          mkdir -p pr-preview
          removed_prs=()

          mapfile -t previews < <(
            while IFS= read -r preview; do
              timestamp="$(git log -1 --format=%ct -- "pr-preview/$preview" 2>/dev/null || echo 0)"
              printf '%s %s\n' "$timestamp" "$preview"
            done < <(find pr-preview -mindepth 1 -maxdepth 1 -type d -name 'pr-*' -printf '%f\n') \
              | sort -nr \
              | awk '{print $2}'
          )

          if (( ${#previews[@]} <= PREVIEW_RETENTION_LIMIT )); then
            echo "removed_prs_json=[]" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          for preview in "${previews[@]:PREVIEW_RETENTION_LIMIT}"; do
            rm -rf "pr-preview/$preview"
            removed_prs+=("${preview#pr-}")
          done

          if git diff --quiet -- pr-preview; then
            echo "removed_prs=" >> "$GITHUB_OUTPUT"
            echo "removed_prs_json=[]" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

          git add pr-preview
          git commit -m "Prune old PR previews"
          git push

          echo "removed_prs=$(IFS=,; echo "${removed_prs[*]}")" >> "$GITHUB_OUTPUT"
          echo "removed_prs_json=$(printf '%s\n' "${removed_prs[@]}" | jq -R . | jq -sc .)" >> "$GITHUB_OUTPUT"

      - name: Comment PR with Preview URL
        if: github.event.action != 'closed'
        uses: marocchino/sticky-pull-request-comment@v2
        with:
          header: pr-preview
          message: |
            🚀 Preview deployment: ${{ steps.deploy-preview.outputs.preview-url }}
            > *Note: Preview may take a moment (GitHub Pages deployment in progress). Please wait and refresh. Track deployment [here](https://github.com/${{ github.repository }}/actions/workflows/pages/pages-build-deployment)*

      - name: Comment on pruned previews
        if: github.event.action != 'closed' && steps.prune-previews.outputs.removed_prs_json != '[]'
        uses: actions/github-script@v7
        env:
          REMOVED_PRS_JSON: ${{ steps.prune-previews.outputs.removed_prs_json }}
          PREVIEW_RETENTION_LIMIT: ${{ env.PREVIEW_RETENTION_LIMIT }}
        with:
          script: |
            const removedPrs = JSON.parse(process.env.REMOVED_PRS_JSON);
            const retentionLimit = process.env.PREVIEW_RETENTION_LIMIT;
            const header = "pr-preview";
            const marker = `<!-- Sticky Pull Request Comment${header} -->`;

            for (const prNumber of removedPrs) {
              const body =
                `Preview deployment for PR #${prNumber} removed.\n\n` +
                `This PR preview was automatically pruned because we keep only the ${retentionLimit} most recently updated previews on GitHub Pages to stay within deployment size limits.\n\n` +
                `If needed, push a new commit to this PR to generate a fresh preview.\n` +
                `${marker}`;

              const { data: comments } = await github.rest.issues.listComments({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: Number(prNumber),
                per_page: 100,
              });

              const existingComment = [...comments].reverse().find((comment) =>
                comment.user?.login === "github-actions[bot]" &&
                comment.body?.includes(marker)
              );

              if (existingComment) {
                await github.rest.issues.updateComment({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  comment_id: existingComment.id,
                  body,
                });
                continue;
              }

              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: Number(prNumber),
                body,
              });
            }

      - name: Cleanup PR Preview on Close
        if: github.event.action == 'closed'
        uses: rossjrw/pr-preview-action@v1.6.3
        with:
          preview-branch: gh-pages
          umbrella-dir: pr-preview
          action: remove