Summary

BEGINNER
│
├── ✅ Understand containers vs VMs
├── ✅ Install Docker
├── ✅ Run pre-built images (nginx, mongodb, redis)
├── ✅ Understand images, containers, tags
├── ✅ Port mapping and volumes
├── ✅ Basic CLI commands
│
INTERMEDIATE
│
├── 📝 Write your first Dockerfile
├── 📝 Build custom images
├── 📝 Multi-stage builds
├── 📝 Docker Compose (multi-container apps)
├── 📝 Docker networking deep dive
├── 📝 Docker secrets and security
│
ADVANCED
│
├── 🚀 Container orchestration (Kubernetes)
├── 🚀 Docker Swarm
├── 🚀 CI/CD with Docker (GitHub Actions, Jenkins)
├── 🚀 Private registries (ECR, GCR, Harbor)
├── 🚀 Container monitoring (Prometheus, Grafana)
├── 🚀 Security scanning (Trivy, Snyk)

1. Dockerfile — Write your own image definitions
2. Docker Compose — Orchestrate multiple containers with one YAML file
3. Multi-Stage Builds — Create tiny production images
4. Docker Swarm — Basic container orchestration
5. Kubernetes — Production-grade container orchestration
6. CI/CD Integration — Automate Docker builds in pipelines

docker run -d -p 8080:80 --name web nginx     # Run container
docker ps -a                                   # List all containers
docker logs -f web                             # Follow logs
docker exec -it web sh                         # Enter container
docker stop web && docker rm web               # Stop and remove
docker images                                  # List images
docker pull node:18-alpine                     # Download image
docker volume create mydata                    # Create volume
docker network create mynet                    # Create network
docker system prune                            # Clean up resources

🎉 Congratulations! You’ve completed Docker Fundamentals. You now understand why Docker exists, how it works under the hood, and how to use it effectively for real-world projects. Keep practicing by containerizing your own projects — that’s the fastest way to master Docker.

Documentation version: 1.0 | Last updated: 2025 | Covers Docker Engine 24.x+