compose-patterns-2025

Docker Compose Patterns for Production (2025)

Overview

This skill documents production-ready Docker Compose patterns and best practices for 2025, based on official Docker documentation and industry standards.

File Format Changes (2025)

IMPORTANT: The version field is now obsolete in Docker Compose v2.42+.

Correct (2025):

services:
  app:
    image: myapp:latest

Incorrect (deprecated):

version: '3.8'  # DO NOT USE
services:
  app:
    image: myapp:latest

Multiple Environment Strategy

Pattern: Base + Environment Overrides

compose.yaml (base):

services:
  app:
    build:
      context: ./app
      dockerfile: Dockerfile
    environment:
      - NODE_ENV=production
    restart: unless-stopped

compose.override.yaml (development - auto-loaded):

services:
  app:
    build:
      target: development
    volumes:
      - ./app/src:/app/src:cached
    environment:
      - NODE_ENV=development
      - DEBUG=*
    ports:
      - "9229:9229"  # Debugger

compose.prod.yaml (production - explicit):

services:
  app:
    build:
      target: production
    deploy:
      replicas: 3
      resources:
        limits:
          cpus: '1'
          memory: 512M
      restart_policy:
        condition: on-failure
        max_attempts: 3

Usage:

# Development (auto-loads compose.override.yaml)
docker compose up

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

# CI/CD
docker compose -f compose.yaml -f compose.ci.yaml up --abort-on-container-exit

Environment Variable Management

Pattern: .env Files per Environment

.env.template (committed to git):

# Database
DB_HOST=sqlserver
DB_PORT=1433
DB_NAME=myapp
DB_USER=sa
# DB_PASSWORD= (set in actual .env)

# Redis
REDIS_HOST=redis
REDIS_PORT=6379
# REDIS_PASSWORD= (set in actual .env)

# Application
NODE_ENV=production
LOG_LEVEL=info

.env.dev:

DB_PASSWORD=Dev!Pass123
REDIS_PASSWORD=redis-dev-123
NODE_ENV=development
LOG_LEVEL=debug