Docker Operations Skill

This skill provides comprehensive guidance for all Docker operations in this project.

When to Use This Skill

Use this skill when the user requests any Docker-related operation:

• Building Docker images
• Running containers
• Managing container lifecycle (start, stop, restart, remove)
• Viewing container logs
• Working with Docker Compose
• Inspecting containers and images
• Docker cleanup operations

Core Operations

Building Images

# Build from Dockerfile in current directory
docker build -t <image-name>:<tag> .

# Build with specific Dockerfile
docker build -f Dockerfile.prod -t <image-name>:<tag> .

# Build with build arguments
docker build --build-arg NODE_ENV=production -t <image-name>:<tag> .

Running Containers

# Run in detached mode
docker run -d --name <container-name> <image-name>

# Run with port mapping
docker run -d -p <host-port>:<container-port> <image-name>

# Run with volume mount
docker run -d -v <host-path>:<container-path> <image-name>

# Run with environment variables
docker run -d -e VAR_NAME=value <image-name>

# Run interactively
docker run -it --rm <image-name> /bin/sh

Container Management

docker ps                    # List running containers
docker ps -a                 # List all containers
docker stop <container>      # Stop a container
docker start <container>     # Start a stopped container
docker restart <container>   # Restart a container
docker rm <container>        # Remove a container
docker rm -f <container>     # Force remove running container

Logs and Inspection

docker logs <container>           # View logs
docker logs -f <container>        # Follow logs
docker logs --tail 100 <container> # Last 100 lines
docker inspect <container>        # Full container details
docker stats                      # Resource usage

Image Management

docker images                # List images
docker pull <image>          # Pull from registry
docker push <image>          # Push to registry
docker rmi <image>           # Remove image
docker tag <src> <dest>      # Tag an image

Docker Compose Operations

docker-compose up              # Start services
docker-compose up -d           # Start in detached mode
docker-compose up --build      # Rebuild and start
docker-compose down            # Stop and remove
docker-compose down -v         # Also remove volumes
docker-compose logs            # View all logs
docker-compose logs <service>  # View service logs
docker-compose ps              # List services
docker-compose exec <svc> sh   # Execute in service

Cleanup Operations

docker system prune           # Remove unused data
docker system prune -a        # Remove all unused images
docker volume prune           # Remove unused volumes
docker network prune          # Remove unused networks
docker container prune        # Remove stopped containers

Additional Resources

Reference Files

• references/docker-commands.md - Complete Docker CLI reference
• references/docker-compose.md - Docker Compose configuration guide

Examples

• examples/Dockerfile.example - Sample Dockerfile for Node.js apps
• examples/docker-compose.example.yml - Sample Docker Compose file

Scripts

• scripts/docker-check.sh - Verify Docker installation and status

Best Practices

1. Always use specific tags - Avoid using latest in production
2. Use multi-stage builds - Reduce image size
3. Don't run as root - Use USER directive in Dockerfile
4. Use .dockerignore - Exclude unnecessary files
5. Health checks - Add HEALTHCHECK to Dockerfiles
6. Resource limits - Set memory and CPU limits in production