docs: add Docker setup for building documentation (#2130)

Add comprehensive Docker-based setup for building OpenCue documentation
without requiring local Ruby installation. This provides multiple
interfaces (helper script, Make, Docker Compose, direct Docker) to
accommodate different workflows and ensures consistent build
environments across all platforms.

Changes:
- Add Dockerfile with Ruby 3.2 Alpine base image
- Add docker-compose.yml with build, serve, and ci profiles
- Add docker-build.sh helper script with fallback support
- Add Makefile for Make-based Docker commands
- Add .dockerignore for optimized builds
- Add DOCKER.md with comprehensive documentation
- Add DOCKER_SETUP_SUMMARY.md for implementation details
- Update README.md to recommend Docker setup as Option 1

Features:
- No Ruby installation required
- Live reload development server
- Persistent gem caching for faster builds
- CI/CD ready with clean build profile
- Backward compatible with local Ruby setup
- Supports Docker Compose v1, v2, or direct Docker commands

Issue Number: close #1869

---------

Signed-off-by: Madduri, Pavan <[email protected]>
Signed-off-by: pmady <[email protected]>

Author: pmady

.github/workflows/docs-pipeline.yml

@@ -55,12 +55,8 @@ jobs:
           VERSION_TAG=${GITHUB_REF#refs/tags/}
           git checkout tags/$VERSION_TAG -b docs-$VERSION_TAG
           
-      - name: Setup Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: '3.2'
-          bundler-cache: true
-          working-directory: ./docs
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
 
       - name: Extract version information
         id: version
@@ -107,7 +103,12 @@ jobs:
           git_hash: "$(git rev-parse --short HEAD)"
           EOF
           
-      - name: Build with Jekyll
+      - name: Build Docker image
+        working-directory: ./docs
+        run: |
+          docker build -t opencue-docs:ci .
+          
+      - name: Build with Jekyll using Docker
         working-directory: ./docs
         run: |
           # Set version in config
@@ -122,24 +123,28 @@ jobs:
           echo "opencue_version: ${{ steps.version.outputs.opencue_version }}" >> _config.yml
           
           # Determine baseurl based on deployment target
-          # For docs.opencue.io deployment, use empty baseurl
-          # For GitHub Pages in forks, use /OpenCue
+          BASEURL=""
           if [ "${{ github.repository }}" = "AcademySoftwareFoundation/OpenCue" ]; then
             # Main repository - deploying to docs.opencue.io
-            bundle exec jekyll build --baseurl ""
+            BASEURL=""
           elif [ "${{ github.event_name }}" = "pull_request" ]; then
             # Pull request - use GitHub Pages path
-            bundle exec jekyll build --baseurl "/OpenCue"
+            BASEURL="/OpenCue"
           else
             # Fork or other deployment - use GitHub Pages path
             if [ "${{ steps.version.outputs.version }}" != "main" ]; then
-              bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}/${{ steps.version.outputs.version }}"
+              BASEURL="${{ steps.pages.outputs.base_path }}/${{ steps.version.outputs.version }}"
             else
-              bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}"
+              BASEURL="${{ steps.pages.outputs.base_path }}"
             fi
           fi
-        env:
-          JEKYLL_ENV: production
+          
+          # Build documentation using Docker
+          docker run --rm \
+            -v "$(pwd):/docs" \
+            -e JEKYLL_ENV=production \
+            opencue-docs:ci \
+            bundle exec jekyll build --baseurl "$BASEURL" --verbose
           
       - name: Create version redirect
         if: github.event_name != 'pull_request'

docs/.dockerignore

@@ -0,0 +1,30 @@
+# Docker ignore file for OpenCue documentation builds
+# Excludes unnecessary files from Docker build context
+
+# Build output
+_site/
+.jekyll-cache/
+.sass-cache/
+
+# Git
+.git/
+.gitignore
+
+# IDE and editor files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+.DS_Store
+
+# Documentation metadata
+nav_order_index.txt
+
+# Docker files (not needed in container)
+.dockerignore
+docker-compose.yml
+
+# Temporary files
+*.tmp
+*.log