Add Docker support and update README

- Add Dockerfile with multi-stage build for Node.js + React
- Add docker-compose.yml for easy local deployment
- Add .dockerignore to exclude unnecessary files
- Add GitHub Actions workflow for automatic Docker image builds and pushes to GHCR
- Add comprehensive DOCKER.md documentation
- Update README with Docker installation instructions

DOCKER.md

@@ -0,0 +1,182 @@
+# Docker Setup for SkyWatch
+
+This guide explains how to build and run SkyWatch using Docker.
+
+## Prerequisites
+
+- Docker and Docker Compose installed on your system
+- A `.env` file configured in the project root (see README.md for configuration details)
+
+## Building Locally
+
+### Using Docker Compose (Recommended)
+
+The easiest way to build and run SkyWatch with Docker:
+
+```bash
+docker-compose up -d
+```
+
+This will:
+1. Build the Docker image
+2. Create a container named `skywatch-monitor`
+3. Start the application on port 3001
+4. Mount a persistent volume for data storage
+
+### Using Docker Directly
+
+To build the image manually:
+
+```bash
+docker build -t skywatch:latest .
+```
+
+To run the container:
+
+```bash
+docker run -d \
+  --name skywatch \
+  -p 3001:3001 \
+  --env-file .env \
+  -v skywatch-data:/app/data \
+  skywatch:latest
+```
+
+## Pushing to GitHub Container Registry (GHCR)
+
+### Automatic Deployment (Recommended)
+
+The project includes a GitHub Actions workflow (`.github/workflows/docker-publish.yml`) that automatically:
+- Builds your Docker image when you push to `main` or create a tag
+- Pushes it to GitHub Container Registry (GHCR)
+- Tags images as:
+  - `latest` (for main branch)
+  - Branch name (e.g., `main`)
+  - Semantic version (if you push a tag like `v1.0.0`)
+  - Short commit SHA
+
+**No configuration needed!** The workflow uses GitHub's built-in authentication.
+
+### Manual Push to GHCR
+
+If you want to push manually:
+
+1. Authenticate with GitHub Container Registry:
+```bash
+echo ${{ secrets.GITHUB_TOKEN }} | docker login ghcr.io -u USERNAME --password-stdin
+# Or use a Personal Access Token (PAT) with `read:packages` and `write:packages` scopes
+```
+
+2. Build and tag the image:
+```bash
+docker build -t ghcr.io/YOUR-USERNAME/monitor:latest .
+```
+
+3. Push to GHCR:
+```bash
+docker push ghcr.io/YOUR-USERNAME/monitor:latest
+```
+
+## Viewing Published Images
+
+Visit: `https://github.com/nmemmert/monitor/pkgs/container/monitor`
+
+Or pull the image:
+```bash
+docker pull ghcr.io/nmemmert/monitor:latest
+```
+
+## Managing Containers
+
+### View running containers
+```bash
+docker ps
+```
+
+### View logs
+```bash
+docker logs skywatch-monitor
+# Follow logs in real-time
+docker logs -f skywatch-monitor
+```
+
+### Stop the container
+```bash
+docker-compose down
+# Or
+docker stop skywatch-monitor
+```
+
+### Remove containers and volumes
+```bash
+docker-compose down -v
+```
+
+## Environment Variables
+
+Make sure your `.env` file is in the project root with required variables:
+
+```env
+PORT=3001
+NODE_ENV=production
+# Add other environment variables as needed
+```
+
+The `.env` file is loaded by Docker Compose from the `env_file` directive.
+
+## Health Checks
+
+The Docker container includes a health check that verifies the API is responding:
+
+```bash
+docker inspect skywatch-monitor --format='{{.State.Health.Status}}'
+```
+
+## Troubleshooting
+
+### Container exits immediately
+Check logs:
+```bash
+docker logs skywatch-monitor
+```
+
+### Port already in use
+Change the port in `docker-compose.yml`:
+```yaml
+ports:
+  - "3002:3001"  # Access at localhost:3002
+```
+
+### Database issues
+Clear the volume and rebuild:
+```bash
+docker-compose down -v
+docker-compose up -d
+```
+
+### Permission issues
+The container runs as non-root user (nodejs). Ensure `.env` file permissions allow reading.
+
+## Production Deployment
+
+For production environments, consider:
+
+1. Using a reverse proxy (nginx, traefik)
+2. Setting up SSL/TLS certificates
+3. Using environment-specific `.env` files
+4. Implementing container orchestration (Kubernetes, Docker Swarm)
+5. Setting resource limits in docker-compose.yml:
+
+```yaml
+services:
+  skywatch:
+    # ... other config
+    deploy:
+      resources:
+        limits:
+          cpus: '1'
+          memory: 512M
+        reservations:
+          cpus: '0.5'
+          memory: 256M
+```