services:

  db:
    image: postgres:16
    environment:
      POSTGRES_DB: django_db
      POSTGRES_USER: django_user
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD}
    volumes:
      - postgres_data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U django_user -d django_db"]
      interval: 5s
      timeout: 5s
      retries: 5

  web:
    build: .
    command: python manage.py runserver 0.0.0.0:8000
    volumes:
      - .:/code
    ports:
      - "8000:8000"
    depends_on:
      db:
        condition: service_healthy
    environment:
      # 与书中 11.6 节一致：settings.py 从环境变量读取数据库密码
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD}
      DATABASE_URL: postgres://django_user:${POSTGRES_PASSWORD:?set POSTGRES_PASSWORD}@db:5432/django_db

volumes:
  postgres_data: