docker-compose-creator

Docker Compose Creator

Design and manage multi-container applications with Docker Compose for both development and production deployments.

When to Use

• Setting up local development environments
• Defining multi-service application stacks
• Managing service dependencies
• Configuring networking between services
• Environment variable management
• Production deployments (single host)
• Testing multi-service interactions

Docker Compose Versions

Version	Released	Features	Use Case
v3.x	2016	Service definitions, networks	Legacy (avoid for new projects)
v2.x	2014	Legacy format	Not recommended
v3.14	2023	Full features, modern syntax	Current default

Use version 3.14 or later for new projects.

Basic Structure

version: '3.14'

services:
  # Service definitions go here

volumes:
  # Named volumes

networks:
  # Custom networks

Full-Featured Example: Web Application Stack

version: '3.14'

services:
  # Frontend (Nginx)
  nginx:
    image: nginx:1.25-alpine
    container_name: webapp-nginx
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./ssl:/etc/nginx/ssl:ro
    depends_on:
      - api
    networks:
      - frontend
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "wget", "--quiet", "--tries=1", "--spider", "http://localhost/health"]
      interval: 30s
      timeout: 5s
      retries: 3
      start_period: 10s

  # API Server (Node.js)
  api:
    build:
      context: ./api
      dockerfile: Dockerfile
      target: production
    container_name: webapp-api
    environment:
      - NODE_ENV=production
      - DATABASE_HOST=postgres
      - REDIS_HOST=redis
      - LOG_LEVEL=info
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started
    networks:
      - frontend
      - backend
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 30s
      timeout: 5s
      retries: 3
      start_period: 10s
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "3"

  # PostgreSQL Database
  postgres:
    image: postgres:15-alpine
    container_name: webapp-db
    environment:
      - POSTGRES_DB=myapp
      - POSTGRES_USER=appuser
      - POSTGRES_PASSWORD=${DB_PASSWORD:?Database password required}
    volumes:
      - postgres_data:/var/lib/postgresql/data
      - ./init-scripts:/docker-entrypoint-initdb.d:ro
    networks:
      - backend
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U appuser -d myapp"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 10s
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "3"

  # Redis Cache
  redis:
    image: redis:7-alpine
    container_name: webapp-cache
    command: redis-server --requirepass ${REDIS_PASSWORD:?Redis password required}
    volumes:
      - redis_data:/data
    networks:
      - backend
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5

  # Background Worker (Optional)
  worker:
    build:
      context: ./worker
      dockerfile: Dockerfile
    container_name: webapp-worker
    environment:
      - NODE_ENV=production
      - DATABASE_HOST=postgres
      - REDIS_HOST=redis
    depends_on:
      - postgres
      - redis
    networks:
      - backend
    restart: unless-stopped

volumes:
  postgres_data:
  redis_data:

networks:
  frontend:
    driver: bridge
  backend:
    driver: bridge

Service Configuration

Image vs Build

# Using pre-built image
services:
  app:
    image: myregistry/myapp:1.0.0

# Building from Dockerfile
services:
  app:
    build: ./app

# Advanced build options
services:
  app:
    build:
      context: ./app
      dockerfile: Dockerfile.prod
      args:
        - BUILD_ENV=production
      target: production

Environment Variables

# Method 1: Inline
services:
  api:
    environment:
      - NODE_ENV=production
      - LOG_LEVEL=info

# Method 2: From file
services:
  api:
    env_file:
      - .env
      - .env.${ENVIRONMENT}

# Method 3: Mixed (with required variable check)
services:
  api:
    environment:
      - DATABASE_PASSWORD=${DB_PASSWORD:?Database password required}
      - DATABASE_HOST=postgres

Resource Limits

services:
  api:
    # Memory: 512MB max, 256MB soft limit
    mem_limit: 512m
    memswap_limit: 1g

    # CPU: 1 core
    cpus: '1.0'

    # File descriptor limit
    ulimits:
      nofile:
        soft: 65536
        hard: 65536

Restart Policy

services:
  api:
    restart: unless-stopped  # Restart unless manually stopped
    # Options: no, always, unless-stopped, on-failure

  worker:
    restart: on-failure
    restart_policy:
      condition: on-failure
      delay: 5s
      max_attempts: 3
      window: 60s

Networking

Service Discovery

services:
  api:
    networks:
      - backend
    environment:
      # Access postgres by service name on backend network
      - DATABASE_HOST=postgres

  postgres:
    networks:
      - backend

Multi-Network Setup

services:
  api:
    networks:
      - frontend  # Can talk to nginx
      - backend   # Can talk to postgres

  nginx:
    networks:
      - frontend  # Can talk to api

  postgres:
    networks:
      - backend   # Can talk to api, worker

networks:
  frontend:
  backend:

Port Mapping

services:
  api:
    ports:
      - "3000:3000"           # Map container 3000 to host 3000
      - "3001:3000"           # Map container 3000 to host 3001
      - "127.0.0.1:3000:3000" # Bind to localhost only

Volumes

Named Volumes

services:
  postgres:
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:

Bind Mounts

services:
  api:
    volumes:
      # Host path : Container path
      - ./src:/app/src
      # Read-only
      - ./config:/app/config:ro
      # With options
      - ./logs:/app/logs:delegated

Tmpfs (Memory-backed)

services:
  api:
    tmpfs:
      - /tmp
      - /run

Depends On

Basic Dependency

services:
  api:
    depends_on:
      - postgres
      - redis

  postgres:
    image: postgres:15

  redis:
    image: redis:7

Conditional Dependency (Health Checks)

services:
  api:
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started

  postgres:
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U user"]
      interval: 10s
      timeout: 5s
      retries: 5

Health Checks

services:
  api:
    healthcheck:
      # Check command
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]

      # Check interval
      interval: 30s

      # Timeout per check
      timeout: 5s

      # Retries before failure
      retries: 3

      # Wait before first check
      start_period: 10s

Logging

services:
  api:
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "3"
        labels: "service=api"

  # Syslog
  worker:
    logging:
      driver: "syslog"
      options:
        syslog-address: "udp://127.0.0.1:514"
        tag: "{{.Name}}"

Development vs Production

Development (docker-compose.yml)

version: '3.14'

services:
  api:
    build: ./api
    ports:
      - "3000:3000"
    volumes:
      - ./api/src:/app/src  # Hot reload
    environment:
      - NODE_ENV=development
    command: npm run dev

Production (docker-compose.prod.yml)

version: '3.14'

services:
  api:
    image: myregistry/myapp:1.0.0
    restart: unless-stopped
    environment:
      - NODE_ENV=production
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 30s
      timeout: 5s
      retries: 3

Running with Override

# Development
docker compose up

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

Common Commands

# Start services
docker compose up

# Start in background
docker compose up -d

# Stop services
docker compose down

# Stop without removing volumes
docker compose stop

# Remove containers, networks, volumes
docker compose down -v

# View logs
docker compose logs -f

# Specific service logs
docker compose logs -f api

# Execute command in service
docker compose exec api npm test

# Run one-off command
docker compose run api npm test

# View service status
docker compose ps

# Rebuild images
docker compose up --build

# Remove and rebuild
docker compose down --rmi all && docker compose up --build

Advanced Patterns

Service Override

# docker-compose.override.yml (git-ignored)
services:
  api:
    volumes:
      - ./src:/app/src  # Local development
    environment:
      - DEBUG=true

Multiple Configurations

# Production with monitoring
docker compose \
  -f docker-compose.yml \
  -f docker-compose.prod.yml \
  -f docker-compose.monitoring.yml \
  up -d

Environment-Specific Files

# Load .env.${ENVIRONMENT}
docker compose --env-file .env.production up -d

Production Deployment Checklist

• All services have healthchecks
• Services use restart: unless-stopped
• Sensitive data in .env (git-ignored)
• Volumes for persistent data
• Resource limits set
• Logging configured
• Networks isolated
• Use specific image tags (never latest)
• Test with docker compose up -d && docker compose ps

Troubleshooting

# Check service status
docker compose ps

# View detailed service info
docker compose exec postgres psql -U user -c "\l"

# Network diagnosis
docker compose exec api ping postgres

# Resource usage
docker stats

# Rebuild and restart
docker compose down --rmi local
docker compose up --build

References

• Docker Compose documentation: https://docs.docker.com/compose/
• Compose file format: https://docs.docker.com/compose/compose-file/
• Best practices: https://docs.docker.com/compose/production/