Docker Compose for Beginners (v2) — Hands-on Practice

Wed, 04 Feb 2026 00:00:00 +0000

Docker Compose v2 - Multi-container Management Tool

Docker Compose is a tool that helps you define and run multiple containers simultaneously through a YAML file. Version v2 brings many improvements in performance and new features.

I. Installation and Preparation

1. Check Docker Compose Version

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# Check current version
docker compose version

# Expected output (v2.x.x)
Docker Compose version v2.24.5

2. Basic Project Structure

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my-app/
├── docker-compose.yml
├── .env
├── app/
│ ├── Dockerfile
│ └── src/
└── nginx/
 └── nginx.conf

II. Docker Compose v2 Syntax

1. Basic docker-compose.yml File

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version: "3.8"

services:
 web:
 build: .
 ports:
 - "3000:3000"
 environment:
 - NODE_ENV=development
 volumes:
 - .:/app
 - /app/node_modules
 depends_on:
 - db

 db:
 image: postgres:15
 environment:
 POSTGRES_DB: myapp
 POSTGRES_USER: user
 POSTGRES_PASSWORD: password
 volumes:
 - postgres_data:/var/lib/postgresql/data
 ports:
 - "5432:5432"

volumes:
 postgres_data:

2. Using .env File

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# .env file
NODE_ENV=development
DB_HOST=db
DB_PORT=5432
DB_NAME=myapp
DB_USER=user
DB_PASSWORD=password

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# docker-compose.yml
services:
 web:
 environment:
 - NODE_ENV=${NODE_ENV}
 - DB_HOST=${DB_HOST}
 - DB_PORT=${DB_PORT}

III. Best Practices for Docker Compose v2

1. Network Management

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version: "3.8"

services:
 frontend:
 build: ./frontend
 networks:
 - frontend-network

 backend:
 build: ./backend
 networks:
 - frontend-network
 - backend-network

 database:
 image: postgres:15
 networks:
 - backend-network

networks:
 frontend-network:
 driver: bridge
 backend-network:
 driver: bridge

2. Health Checks

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services:
 web:
 build: .
 healthcheck:
 test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
 interval: 30s
 timeout: 10s
 retries: 3
 start_period: 40s

 db:
 image: postgres:15
 healthcheck:
 test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER}"]
 interval: 10s
 timeout: 5s
 retries: 5

3. Resource Limits

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services:
 web:
 build: .
 deploy:
 resources:
 limits:
 cpus: "0.5"
 memory: 512M
 reservations:
 cpus: "0.25"
 memory: 256M

IV. Common Docker Compose v2 Commands

1. Basic Commands

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# Start services (detached mode)
docker compose up -d

# View logs
docker compose logs -f

# Stop services
docker compose down

# Rebuild and restart
docker compose up --build -d

# View service status
docker compose ps

2. Advanced Commands

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# Run a command inside a container
docker compose exec web bash

# Scale a service
docker compose up --scale web=3 -d

# View resource usage
docker compose top

# Validate compose file
docker compose config

V. Real-World Example: Web App with Database

1. Node.js + PostgreSQL + Redis

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version: "3.8"

services:
 app:
 build:
 context: .
 dockerfile: Dockerfile
 ports:
 - "3000:3000"
 environment:
 - NODE_ENV=development
 - DATABASE_URL=postgresql://user:password@db:5432/myapp
 - REDIS_URL=redis://redis:6379
 volumes:
 - .:/app
 - /app/node_modules
 depends_on:
 db:
 condition: service_healthy
 redis:
 condition: service_started
 restart: unless-stopped

 db:
 image: postgres:15-alpine
 environment:
 POSTGRES_DB: myapp
 POSTGRES_USER: user
 POSTGRES_PASSWORD: password
 volumes:
 - postgres_data:/var/lib/postgresql/data
 - ./init.sql:/docker-entrypoint-initdb.d/init.sql
 healthcheck:
 test: ["CMD-SHELL", "pg_isready -U user"]
 interval: 10s
 timeout: 5s
 retries: 5
 restart: unless-stopped

 redis:
 image: redis:7-alpine
 command: redis-server --appendonly yes
 volumes:
 - redis_data:/data
 restart: unless-stopped

 nginx:
 image: nginx:alpine
 ports:
 - "80:80"
 volumes:
 - ./nginx.conf:/etc/nginx/nginx.conf
 depends_on:
 - app
 restart: unless-stopped

volumes:
 postgres_data:
 redis_data:

2. nginx.conf File

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events {
 worker_connections 1024;
}

http {
 upstream app {
 server app:3000;
 }

 server {
 listen 80;

 location / {
 proxy_pass http://app;
 proxy_set_header Host $host;
 proxy_set_header X-Real-IP $remote_addr;
 }
 }
}

VI. Override and Multiple Environments

1. docker-compose.override.yml

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# docker-compose.override.yml (automatically loaded)
version: "3.8"

services:
 app:
 volumes:
 - .:/app
 environment:
 - DEBUG=true

2. Environment-specific Files

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# Development
docker compose -f docker-compose.yml -f docker-compose.dev.yml up -d

# Production
docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d

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# docker-compose.prod.yml
version: "3.8"

services:
 app:
 restart: always
 deploy:
 resources:
 limits:
 memory: 1G
 environment:
 - NODE_ENV=production

Implementation Notes

When applying to your project, keep these important points in mind:
- Always use .env files for sensitive data
- Implement health checks for critical services
- Use named volumes for persistent data
- Configure appropriate restart policies
Best practices:
- Separate networks for security
- Use specific image tags instead of latest
- Implement a proper logging strategy
Troubleshooting:
- Use docker compose logs to debug
- Check docker compose config before deploying
- Monitor resource usage with docker compose top

🎯 Conclusion

Docker Compose v2 is a powerful tool that helps you manage multi-container applications with ease. With the best practices above, you can build and deploy applications professionally and efficiently! 🚀

Try experimenting with the examples above and gradually apply them to your real-world projects. 😊

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