Docker Compose for Production

While Kubernetes handles large-scale deployments, Docker Compose is excellent for small to medium production workloads. This guide covers production-grade configurations.

Production-Ready docker-compose.yml

services:
  api:
    image: myapp/api:${TAG:-latest}
    restart: unless-stopped
    
    # Resource limits
    deploy:
      resources:
        limits:
          cpus: '2'
          memory: 512M
        reservations:
          memory: 256M
      replicas: 2
    
    # Health check
    healthcheck:
      test: ["CMD", "wget", "-qO-", "http://localhost:3000/health"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s
    
    environment:
      NODE_ENV: production
      PORT: 3000
    
    # Secrets (not in environment!)
    secrets:
      - db_password
      - jwt_secret
    
    networks:
      - frontend
      - backend
    
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_healthy
    
    logging:
      driver: "json-file"
      options:
        max-size: "10m"
        max-file: "3"

  postgres:
    image: postgres:15-alpine
    restart: unless-stopped
    
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER}"]
      interval: 10s
      timeout: 5s
      retries: 5
    
    environment:
      POSTGRES_DB: myapp
      POSTGRES_USER: myapp
      POSTGRES_PASSWORD_FILE: /run/secrets/db_password
    
    volumes:
      - postgres_data:/var/lib/postgresql/data
      - ./init.sql:/docker-entrypoint-initdb.d/init.sql:ro
    
    secrets:
      - db_password
    
    networks:
      - backend

  redis:
    image: redis:7-alpine
    restart: unless-stopped
    command: redis-server --appendonly yes --requirepass-file /run/secrets/redis_password
    
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
    
    volumes:
      - redis_data:/data
    
    secrets:
      - redis_password
    
    networks:
      - backend

  nginx:
    image: nginx:alpine
    restart: unless-stopped
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./certs:/etc/nginx/certs:ro
    networks:
      - frontend
    depends_on:
      - api

secrets:
  db_password:
    file: ./secrets/db_password.txt
  jwt_secret:
    file: ./secrets/jwt_secret.txt
  redis_password:
    file: ./secrets/redis_password.txt

volumes:
  postgres_data:
  redis_data:

networks:
  frontend:
  backend:
    internal: true  # Not accessible from outside

Reading Secrets in Application

// Node.js: read Docker secrets from /run/secrets/
const fs = require('fs');

function getSecret(name) {
  const secretPath = `/run/secrets/${name}`;
  try {
    return fs.readFileSync(secretPath, 'utf8').trim();
  } catch {
    // Fallback to environment variable for local dev
    return process.env[name.toUpperCase()];
  }
}

const config = {
  dbPassword: getSecret('db_password'),
  jwtSecret: getSecret('jwt_secret'),
};

Rolling Updates

# Pull new image
docker compose pull api

# Rolling restart (update one replica at a time)
docker compose up -d --no-deps --scale api=2 api

# Or use update order
docker compose up -d api
# Compose will stop old container after new one is healthy

Backup and Restore

# Backup PostgreSQL
docker compose exec postgres pg_dump -U myapp myapp | gzip > backup-$(date +%Y%m%d).sql.gz

# Restore
gunzip -c backup-20240101.sql.gz | docker compose exec -T postgres psql -U myapp myapp

# Backup volumes
docker run --rm   -v myapp_postgres_data:/data   -v $(pwd)/backups:/backup   alpine tar czf /backup/postgres-$(date +%Y%m%d).tar.gz /data

Environment-Specific Overrides

# docker-compose.override.yml (auto-loaded in development)
services:
  api:
    build: .  # Build from source in dev
    volumes:
      - .:/app  # Hot reload
    environment:
      NODE_ENV: development
    ports:
      - "9229:9229"  # Debug port
  
  postgres:
    ports:
      - "5432:5432"  # Expose in dev

# Production: explicit file selection
docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d

# Development: uses override automatically
docker compose up -d

Monitoring with Compose

# Add Prometheus + Grafana
  prometheus:
    image: prom/prometheus
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
    networks:
      - backend

  grafana:
    image: grafana/grafana
    ports:
      - "3001:3000"
    environment:
      GF_SECURITY_ADMIN_PASSWORD_FILE: /run/secrets/grafana_password
    secrets:
      - grafana_password
    networks:
      - backend

Summary

Production Docker Compose patterns:

• Always use health checks for dependency ordering
• Store secrets as files, not environment variables
• Use internal networks to isolate backend services
• Set resource limits to prevent container starvation
• Use environment-specific override files
• Automate backups for stateful services