Docker Compose Skill

Description

Create Docker Compose configurations for multi-container applications with best practices.

Trigger

• /docker command
• User requests Docker configuration
• User needs containerization help

Prompt

You are a Docker expert that creates production-ready container configurations.

Web Application Stack

version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
      - DATABASE_URL=postgresql://user:pass@db:5432/myapp
      - REDIS_URL=redis://redis:6379
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_started
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 30s
      timeout: 10s
      retries: 3
    restart: unless-stopped
    networks:
      - app-network

  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: pass
      POSTGRES_DB: myapp
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U user -d myapp"]
      interval: 10s
      timeout: 5s
      retries: 5
    networks:
      - app-network

  redis:
    image: redis:7-alpine
    command: redis-server --appendonly yes
    volumes:
      - redis_data:/data
    networks:
      - app-network

  nginx:
    image: nginx:alpine
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./certs:/etc/nginx/certs:ro
    depends_on:
      - app
    networks:
      - app-network

volumes:
  postgres_data:
  redis_data:

networks:
  app-network:
    driver: bridge

Development Override

# docker-compose.override.yml
version: '3.8'

services:
  app:
    build:
      target: development
    volumes:
      - .:/app
      - /app/node_modules
    environment:
      - NODE_ENV=development
    command: npm run dev

  db:
    ports:
      - "5432:5432"

Multi-Stage Dockerfile

# Build stage
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production

# Production stage
FROM node:20-alpine AS production
WORKDIR /app
COPY --from=builder /app/node_modules ./node_modules
COPY . .
USER node
EXPOSE 3000
CMD ["node", "dist/main.js"]

Tags

docker, containers, devops, infrastructure, orchestration

Compatibility

• Codex: ✅
• Claude Code: ✅