Docker Compose Configuration Skill

Overview

This skill generates Docker Compose configurations for multi-container applications. It creates properly structured compose files with:

• Service definitions

• Network configuration

• Volume management

• Health checks

• Dependencies

• Environment configuration

Activation

Use this skill when:

• Creating a new compose file

• Adding services to existing compose

• Configuring container orchestration

• Setting up development or production environments

Process

1. Understand Requirements

Gather information about:

• Required services (web, api, database, cache, etc.)

• Environment (development/production)

• Networking needs (internal, external, SSL)

• Persistence requirements

• Scaling needs

2. Consult Documentation

Read relevant documentation:

• 03-compose-fundamentals.md for structure

• 04-networking.md for networks

• 05-databases.md for database services

• 06-services.md for dependencies

• 08-volumes.md for persistence

3. Generate Configuration

Create compose file following best practices:

Modern compose (no version field)

services: app: build: context: . dockerfile: Dockerfile restart: unless-stopped ports: - "3000:3000" environment: - NODE_ENV=production depends_on: db: condition: service_healthy networks: - frontend - backend healthcheck: test: ["CMD", "curl", "-f", "http://localhost:3000/health"] interval: 30s timeout: 10s retries: 3

db: image: postgres:16-alpine restart: unless-stopped environment: POSTGRES_USER: ${DB_USER} POSTGRES_PASSWORD: ${DB_PASSWORD} POSTGRES_DB: ${DB_NAME} volumes: - postgres_data:/var/lib/postgresql/data networks: - backend healthcheck: test: ["CMD-SHELL", "pg_isready -U ${DB_USER}"] interval: 10s timeout: 5s retries: 5

volumes: postgres_data:

networks: frontend: backend: internal: true

Service Patterns

Web Application

services: web: build: . ports: - "80:80" depends_on: - api

API Service

services: api: build: ./api expose: - "3000" environment: - DATABASE_URL=postgresql://user:pass@db:5432/app depends_on: db: condition: service_healthy

Database Service

services: db: image: postgres:16-alpine volumes: - db_data:/var/lib/postgresql/data environment: POSTGRES_PASSWORD: ${DB_PASSWORD} healthcheck: test: ["CMD-SHELL", "pg_isready"] interval: 10s retries: 5

Cache Service

services: redis: image: redis:7-alpine command: redis-server --appendonly yes volumes: - redis_data:/data

Background Worker

services: worker: build: . command: npm run worker depends_on: - db - redis

Network Patterns

Internal Database Network

networks: backend: internal: true # No external access

External Shared Network

networks: proxy: external: true name: traefik_proxy

Volume Patterns

Named Volume

volumes: postgres_data:

Bind Mount (Development)

volumes:

• ./src:/app/src

Anonymous Volume

volumes:

• /app/node_modules

Environment Patterns

Direct Values

environment:

• NODE_ENV=production

From .env File

env_file:

• .env

With Defaults

environment:

• DB_HOST=${DB_HOST:-localhost}

Output

Generated compose file includes:

• All required services

• Proper network configuration

• Volume definitions

• Health checks

• Dependency management

• Environment configuration

• Comments for complex settings