github: Create docker container with documentation on every push to n…

…ew docs repo

.github/actions/container/Dockerfile

@@ -0,0 +1,3 @@
+FROM ghcr.io/rtsp/docker-lighttpd:latest
+
+COPY .vitepress/dist/ /var/www/html/2.4/

.github/workflows/container.yml

@@ -0,0 +1,56 @@
+name: Build Container
+
+on:
+  push:
+    branches:
+      - new-ce-documentation
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  releasenew:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+    - name: Setup Node
+      uses: actions/setup-node@v3
+      with:
+        node-version: 20
+        cache: npm
+    - name: Install Dependencies
+      run: npm ci
+    - name: Build with VitePress
+      run: |
+        npm run docs:build
+    # Login against a Docker registry
+    # https://github.com/docker/login-action
+    - name: Log into registry ${{ env.REGISTRY }}
+      uses: docker/login-action@v3
+      with:
+        registry: ${{ env.REGISTRY }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+    # Extract metadata (tags, labels) for Docker
+    # https://github.com/docker/metadata-action
+    - name: Extract Docker metadata
+      id: meta
+      uses: docker/metadata-action@v5
+      with:
+        images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+    # Build and push Docker image with Buildx
+    # https://github.com/docker/build-push-action
+    - name: Build and push Docker image
+      id: build-and-push
+      uses: docker/build-push-action@v5
+      with:
+        context: .
+        file: .github/actions/container/Dockerfile
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}

README.md

@@ -31,7 +31,7 @@ From [VitePress](https://vitepress.dev/guide/getting-started#prerequisites):
 > [!WARNING]
 > Ubuntu 22.04 LTS (and prior) does NOT contain a new enough version of nodejs.
 >
-> Either run in a container (see https://hub.docker.com/\_/node) or install
+> Either run in a container (see https://hub.docker.com/_/node) or install
 > via out-of-band packages (see https://github.com/nodesource/distributions).
 
 ## Installation
@@ -96,6 +96,27 @@ However, some errors only occur when viewing a page, and will oftentimes
 result in a blank or incomplete page render. In these cases, looking at the
 browser developer console will generally show the error that has occurred.
 
+## Docker Container
+
+An updated Docker container is produced after every code addition, and can be
+used to view the documentation locally.
+
+Container installation information can be found at:
+https://github.com/dovecot/documentation/pkgs/container/documentation
+
+The container exposes a web server on port 80, and the documentation is available
+in the `2.4` directory.
+
+### Example
+
+Provide access to Dovecot documentation at `http://localhost:8080/`:
+
+```console
+docker run --rm \
+  -p 8080:80 \
+  ghcr.io/dovecot/documentation:latest
+```
+
 ## Dovecot-specific VitePress Features
 
 ### Directory Structure