Docker Compose Setup

Docker Compose Setup Skill

Master Docker Compose for multi-container application orchestration with service dependencies, health checks, and environment management.

Purpose

Design and configure Docker Compose files for development and production environments with proper service orchestration.

Parameters

Modern Compose File (2024-2025)

Note: The version field is deprecated. Start directly with services:.

services:
  frontend:
    build:
      context: ./frontend
      target: production
    ports:
      - "80:80"
    depends_on:
      backend:
        condition: service_healthy
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost/health"]
      interval: 30s
      timeout: 10s
      retries: 3
    restart: unless-stopped

  backend:
    build: ./backend
    expose:
      - "3000"
    environment:
      DATABASE_URL: postgres://user:${DB_PASSWORD}@database:5432/app
    depends_on:
      database:
        condition: service_healthy
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 10s
      timeout: 5s
      retries: 5

  database:
    image: postgres:16-alpine
    volumes:
      - db_data:/var/lib/postgresql/data
    environment:
      POSTGRES_PASSWORD: ${DB_PASSWORD}
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U postgres"]
      interval: 5s
      timeout: 5s
      retries: 5

volumes:
  db_data:

Environment Management

Base + Override Pattern

# docker-compose.yaml (base)
services:
  app:
    image: myapp:latest

# docker-compose.override.yaml (dev - auto-loaded)
services:
  app:
    build: .
    volumes:
      - ./src:/app/src
    environment:
      - DEBUG=true

# docker-compose.prod.yaml (production)
services:
  app:
    deploy:
      replicas: 3
    restart: always

# Development (loads override automatically)
docker compose up

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

Environment Variables

# .env file (auto-loaded)
DB_PASSWORD=secret123
APP_VERSION=1.2.3

# Using in compose
environment:
  - DB_PASSWORD=${DB_PASSWORD}
  - VERSION=${APP_VERSION:-latest}  # Default value

Service Profiles

services:
  app:
    image: myapp

  # Only with --profile debug
  debugger:
    image: debug-tools
    profiles:
      - debug

  # Only with --profile testing
  test-db:
    image: postgres:alpine
    profiles:
      - testing

docker compose up                     # app only
docker compose --profile debug up     # app + debugger

Common Commands

# Start services
docker compose up -d

# Rebuild and start
docker compose up -d --build

# View logs
docker compose logs -f backend

# Scale service
docker compose up -d --scale backend=3

# Stop and clean
docker compose down -v

# Validate config
docker compose config

Error Handling

Common Errors

Fallback Strategy

1. Validate with docker compose config
2. Start services individually
3. Use --no-deps to skip dependencies

Troubleshooting

Debug Checklist

• Valid YAML? docker compose config
• Images available? docker compose pull
• Dependencies healthy? Check healthchecks
• Environment set? Check .env file

Health Check Debugging

# Check health status
docker inspect --format='{{json .State.Health}}' <container>

# View health logs
docker inspect --format='{{range .State.Health.Log}}{{.Output}}{{end}}' <container>

Usage

Skill("docker-compose-setup")

Related Skills

• docker-networking
• docker-volumes
• docker-production