Docker Compose Grundlagen

Docker Compose ermöglicht das Definieren und Ausführen von Multi-Container-Anwendungen. Mit einer YAML-Datei konfigurieren Sie alle Services, Netzwerke und Volumes.

Installation

# Docker Compose Plugin (empfohlen)
sudo apt install docker-compose-plugin -y

# Version prüfen
docker compose version

Grundlegende Syntax

# docker-compose.yml
version: '3.8'

services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    volumes:
      - ./html:/usr/share/nginx/html
    restart: unless-stopped

  db:
    image: mysql:8
    environment:
      MYSQL_ROOT_PASSWORD: geheim
      MYSQL_DATABASE: myapp
    volumes:
      - db_data:/var/lib/mysql
    restart: unless-stopped

volumes:
  db_data:

Wichtige Befehle

# Container starten
docker compose up -d

# Container stoppen
docker compose down

# Logs anzeigen
docker compose logs -f

# Container neustarten
docker compose restart

# Status anzeigen
docker compose ps

# Container und Volumes löschen
docker compose down -v

Praktische Beispiele

WordPress mit MySQL

version: '3.8'

services:
  wordpress:
    image: wordpress:latest
    ports:
      - "8080:80"
    environment:
      WORDPRESS_DB_HOST: db
      WORDPRESS_DB_USER: wordpress
      WORDPRESS_DB_PASSWORD: geheim123
      WORDPRESS_DB_NAME: wordpress
    volumes:
      - wordpress_data:/var/www/html
    depends_on:
      - db
    restart: unless-stopped

  db:
    image: mysql:8
    environment:
      MYSQL_DATABASE: wordpress
      MYSQL_USER: wordpress
      MYSQL_PASSWORD: geheim123
      MYSQL_ROOT_PASSWORD: rootgeheim
    volumes:
      - db_data:/var/lib/mysql
    restart: unless-stopped

volumes:
  wordpress_data:
  db_data:

Node.js mit MongoDB und Redis

version: '3.8'

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      NODE_ENV: production
      MONGO_URI: mongodb://mongo:27017/myapp
      REDIS_HOST: redis
    depends_on:
      - mongo
      - redis
    restart: unless-stopped

  mongo:
    image: mongo:6
    volumes:
      - mongo_data:/data/db
    restart: unless-stopped

  redis:
    image: redis:alpine
    restart: unless-stopped

volumes:
  mongo_data:

Mit Dockerfile bauen

version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - "3000:3000"

Netzwerke

version: '3.8'

services:
  frontend:
    image: nginx
    networks:
      - frontend

  backend:
    image: node
    networks:
      - frontend
      - backend

  db:
    image: postgres
    networks:
      - backend

networks:
  frontend:
  backend:

Umgebungsvariablen

# .env Datei
MYSQL_ROOT_PASSWORD=supersecret
APP_PORT=8080

# docker-compose.yml
services:
  db:
    image: mysql
    environment:
      MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
    ports:
      - "${APP_PORT}:80"

Health Checks

services:
  web:
    image: nginx
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s

Ressourcen-Limits

services:
  app:
    image: myapp
    deploy:
      resources:
        limits:
          cpus: '0.5'
          memory: 512M
        reservations:
          memory: 256M

Nützliche Tipps

# Nur bestimmten Service starten
docker compose up -d db

# Container neu bauen
docker compose up -d --build

# Alte Container entfernen
docker compose down --remove-orphans

# Shell in Container
docker compose exec web bash

Weitere Hilfe

• 📖 Docker Compose Dokumentation
• 📧 E-Mail: support@enjyn.de