docker-compose

What I do

• •Create docker-compose.yml for service orchestration
• •Define multi-stage builds and service dependencies
• •Configure volumes, networks, and environment variables
• •Set up health checks and restart policies
• •Debug container startup and networking issues
• •Manage container lifecycle (start, stop, rebuild)

When to use me

Use me when orchestrating multi-container applications, especially when:

• •Setting up local development environments
• •Configuring production deployments
• •Managing service dependencies and networking
• •Debugging container communication issues
• •Optimizing image sizes and build times

Common commands

• •docker-compose up -d - Start services in detached mode
• •docker-compose down - Stop and remove containers
• •docker-compose build - Build images
• •docker-compose logs -f - Follow logs
• •docker-compose exec service sh - Execute command in container
• •docker-compose ps - List running containers

Service configuration

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
    volumes:
      - ./data:/app/data
    depends_on:
      - db
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 30s
      timeout: 10s
      retries: 3

Networking patterns

• •Create custom networks for service isolation
• •Use service names as hostnames (e.g., db:5432)
• •Expose ports only where necessary (internal vs external)
• •Configure DNS resolution for service discovery

Volume strategies

• •Named volumes for persistent data
• •Bind mounts for live code reloading
• •Temporary volumes for caches and logs
• •Backup named volumes before major changes

Build optimization

• •Use multi-stage builds to reduce image size
• •Cache dependencies with COPY layers
• •Use .dockerignore to exclude unnecessary files
• •Build once, run multiple times (no build in production containers)

Health checks

• •Define health checks for critical services
• •Use depends_on: {condition: service_healthy} for ordering
• •Implement readiness endpoints in applications
• •Configure appropriate timeouts and retries

Debugging tips

• •Use docker-compose logs --tail=100 service for recent logs
• •Enter container with docker-compose exec service sh
• •Check networking with docker network inspect
• •Verify environment variables with docker-compose config
• •Use --no-cache flag when troubleshooting builds