Apa itu Docker Compose?

Docker Compose memungkinkan kita mendefinisikan dan menjalankan multi-container application menggunakan satu file YAML. Sangat berguna untuk development environment yang butuh beberapa service sekaligus.

docker-compose.yml Dasar

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

  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_DB: myapp
      POSTGRES_USER: admin
      POSTGRES_PASSWORD: secret
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data

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

volumes:
  postgres_data:

Command Docker Compose

# Start semua service (background)
docker compose up -d

# Build ulang dan start
docker compose up -d --build

# Stop semua
docker compose down

# Stop dan hapus volumes
docker compose down -v

# Lihat logs
docker compose logs -f app

# Exec command di container
docker compose exec app sh
docker compose exec db psql -U admin myapp

Environment Variables

# .env file otomatis dibaca oleh compose
# .env
DB_PASSWORD=secret123

# docker-compose.yml
services:
  db:
    environment:
      POSTGRES_PASSWORD: ${DB_PASSWORD}