Add GitHub Actions workflow for automated Docker builds

.github/workflows/docker.yml

@@ -0,0 +1,56 @@
+name: Docker Build
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      # Login to Docker Hub (requires DOCKER_USERNAME and DOCKER_PASSWORD secrets)
+      - name: Log in to Docker Hub
+        if: github.event_name != 'pull_request' && vars.DOCKER_ENABLED == 'true'
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          # Image will be named cloud-server under your Docker Hub username
+          # Falls back to GitHub repository owner for local builds
+          images: |
+            ${{ secrets.DOCKER_USERNAME || github.repository_owner }}/cloud-server
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=raw,value=latest,enable={{is_default_branch}}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          # Only push if not a PR and DOCKER_ENABLED variable is set
+          push: ${{ github.event_name != 'pull_request' && vars.DOCKER_ENABLED == 'true' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

README.md

@@ -24,6 +24,19 @@ docker compose up -d
 
 The server will be available at ws://localhost:9080/. Logs are persisted in the `./logs` directory on the host.
 
+Alternatively, if Docker Hub publishing is configured for this repository, you can pull the pre-built image:
+
+```bash
+# To find the Docker Hub username:
+# 1. Go to the repository's Actions tab on GitHub
+# 2. Look for successful "Docker Build" workflow runs
+# 3. Check the workflow logs for the image name being pushed
+# OR ask the repository maintainer for the Docker Hub username
+
+docker pull <username>/cloud-server:latest
+docker run -d -p 9080:9080 <username>/cloud-server:latest
+```
+
 To stop the server:
 
 ```bash
@@ -108,3 +121,24 @@ server {
 ```
 
 You may also want to make a systemd service file for the server, but this is left as an exercise to the reader.
+
+## Development
+
+### CI/CD
+
+This repository includes a GitHub Actions workflow that automatically builds and publishes Docker images:
+
+- **Trigger**: Automatically runs on push to `main` branch and on version tags (e.g., `v1.0.0`)
+- **Image name**: `cloud-server`
+- **Tags**: 
+  - `latest` tag for main branch pushes
+  - Semantic version tags (e.g., `1.0.0`, `1.0`) for version tag pushes
+
+To enable Docker Hub publishing, configure the following repository secrets:
+- `DOCKER_USERNAME`: Your Docker Hub username
+- `DOCKER_PASSWORD`: Your Docker Hub password or access token
+
+And set this repository variable:
+- `DOCKER_ENABLED`: Set to `true` to enable Docker Hub publishing
+
+The workflow will build the Docker image on every push and only push to Docker Hub if the `DOCKER_ENABLED` variable is set to `true`.