docker-compose

Docker Compose — Multi-Container Orchestration

Manage multi-container Docker applications with docker-compose. Define services, networks, volumes, and dependencies in YAML. Perfect for local development, testing, and simple production deployments.

When to Use

• Setting up local development environments
• Running multi-service applications (app + database + cache)
• Testing microservices locally
• CI/CD pipeline containers
• Simple production deployments

Core Concepts

Services

services:
  app:
    build: .
    ports:
      - "3000:3000"
    depends_on:
      - db
  
  db:
    image: postgres:15
    environment:
      POSTGRES_PASSWORD: secret
    volumes:
      - db-data:/var/lib/postgresql/data

volumes:
  db-data:

Networks

networks:
  frontend:
  backend:

services:
  app:
    networks:
      - frontend
      - backend
  
  db:
    networks:
      - backend

Common Patterns

1. Full-Stack App (Frontend + Backend + Database)

version: '3.8'

services:
  frontend:
    build: ./frontend
    ports:
      - "3000:3000"
    environment:
      - REACT_APP_API_URL=http://localhost:8000
    depends_on:
      - backend

  backend:
    build: ./backend
    ports:
      - "8000:8000"
    environment:
      - DATABASE_URL=postgresql://user:pass@db:5432/myapp
    depends_on:
      - db

  db:
    image: postgres:15
    environment:
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=pass
      - POSTGRES_DB=myapp
    volumes:
      - postgres-data:/var/lib/postgresql/data

volumes:
  postgres-data:

2. Microservices with Redis Cache

services:
  api:
    build: ./api
    ports:
      - "8000:8000"
    environment:
      - REDIS_URL=redis://cache:6379
    depends_on:
      - cache
      - db

  worker:
    build: ./worker
    environment:
      - REDIS_URL=redis://cache:6379
    depends_on:
      - cache

  cache:
    image: redis:7-alpine
    ports:
      - "6379:6379"

  db:
    image: postgres:15
    environment:
      - POSTGRES_PASSWORD=secret
    volumes:
      - db-data:/var/lib/postgresql/data

volumes:
  db-data: