Docker: 第 3 フェーズ統合実践

docker compose up -d

# ============================================
# docker-compose.yml - EC マイクロサービス
# ============================================

services:
  # ---------- フロントエンド ----------
  nginx:
    image: nginx:1.25-alpine
    ports:
      - "80:80"
    volumes:
      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
      - react-build:/usr/share/nginx/html:ro
    depends_on:
      api:
        condition: service_healthy
    restart: unless-stopped
    networks:
      - frontend
      - backend
    healthcheck:
      test: ["CMD", "nginx", "-t"]
      interval: 30s
      timeout: 5s

  react:
    build:
      context: ./frontend
      dockerfile: Dockerfile
    volumes:
      - react-build:/app/build
    networks:
      - frontend

  # ---------- バックエンド ----------
  api:
    build:
      context: ./api
      dockerfile: Dockerfile
    environment:
      DATABASE_URL: postgresql://appuser:${DB_PASSWORD:-secret}@postgres:5432/${DB_NAME:-ecommerce}
      REDIS_URL: redis://redis:6379
      RABBITMQ_URL: amqp://guest:guest@rabbitmq:5672
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started
    restart: unless-stopped
    deploy:
      replicas: 3
      resources:
        limits:
          cpus: "1.0"
          memory: 512M
    networks:
      - backend
      - db-net
      - cache-net
    healthcheck:
      test: ["CMD", "wget", "-qO-", "http://localhost:8080/health"]
      interval: 15s
      timeout: 5s
      retries: 3
      start_period: 10s
    logging:
      driver: json-file
      options:
        max-size: "10m"
        max-file: "5"

  # ---------- データストア ----------
  postgres:
    image: postgres:15-alpine
    environment:
      POSTGRES_USER: appuser
      POSTGRES_PASSWORD: ${DB_PASSWORD:-secret}
      POSTGRES_DB: ${DB_NAME:-ecommerce}
    volumes:
      - pg-data:/var/lib/postgresql/data
    restart: unless-stopped
    networks:
      - db-net
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U appuser"]
      interval: 5s
      timeout: 5s
      retries: 5

  redis:
    image: redis:7-alpine
    command: redis-server --appendonly yes
    volumes:
      - redis-data:/data
    restart: unless-stopped
    networks:
      - cache-net
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s

  rabbitmq:
    image: rabbitmq:3-management-alpine
    ports:
      - "15672:15672"   # 管理 UI
    environment:
      RABBITMQ_DEFAULT_USER: guest
      RABBITMQ_DEFAULT_PASS: guest
    volumes:
      - mq-data:/var/lib/rabbitmq
    restart: unless-stopped
    networks:
      - backend

# ---------- ボリューム ----------
volumes:
  pg-data:
  redis-data:
  mq-data:
  react-build:

# ---------- ネットワーク ----------
networks:
  frontend:
  backend:
  db-net:
    internal: true   # 外部アクセス不可
  cache-net:
    internal: true

# nginx.conf
upstream api_backend {
    server api:8080;   # 3 レプリカへ Docker DNS ラウンドロビン
}

server {
    listen 80;
    server_name localhost;

    # 静的ファイル(React SPA)
    location / {
        root /usr/share/nginx/html;
        try_files $uri $uri/ /index.html;
    }

    # API プロキシ
    location /api/ {
        proxy_pass http://api_backend/;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

# docker-compose.dev.yml
services:
  api:
    build:
      context: ./api
      dockerfile: Dockerfile.dev
    volumes:
      - ./api/src:/app/src   # ホットリロード
    environment:
      GO_ENV: development
    deploy:
      replicas: 1            # デバッグ用に単一レプリカ

  # dev 専用: データベース管理 UI
  adminer:
    image: adminer
    ports:
      - "8081:8080"
    profiles: ["dev"]
    networks:
      - db-net

# 各サービスのヘルスチェック設定
services:
  api:
    healthcheck:
      test: ["CMD", "wget", "--spider", "-q", "http://localhost:8080/health"]
      interval: 10s
      timeout: 5s
      retries: 3
      start_period: 20s

  postgres:
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U $$POSTGRES_USER"]
      interval: 5s
      timeout: 3s
      retries: 5

  redis:
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 3

# ============================================
# 完全なウォークスルー: EC マイクロサービス
# ============================================

# 1. 全サービスをビルドして起動
docker compose up -d --build

# 2. 全サービスが動作中か確認
docker compose ps

# 3. ヘルスステータスを確認
docker compose ps --format "table {{.Name}}\t{{.Status}}"

# 4. API をテスト
curl -s http://localhost/api/health | python3 -m json.tool

# 5. 負荷分散を確認(複数リクエストで異なるレプリカへ)
for i in $(seq 1 6); do
  curl -s http://localhost/api/health | jq -r '.hostname'
done

# 6. API からデータベース接続を確認
docker compose exec api wget -qO- http://localhost:8080/health

# 7. RabbitMQ 管理 UI にアクセス
# ブラウザで http://localhost:15672 を開く (guest/guest)

# 8. ログを表示
docker compose logs -f api

# 9. API を 5 レプリカにスケール
docker compose up -d --scale api=5

# 10. クリーンアップ
docker compose down
docker compose down -v  # データボリュームも削除