db:
    image: postgres:10.2-alpine
    container_name: db
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: password
      POSTGRES_DB: demodb
      PGDATA: /var/lib/postgresql/data
    ports:
      - "5432:5432"
    volumes:
      - ./.data:/var/lib/postgresql/data
      - ./config/my-postgres.conf:/etc/postgresql.conf
    command: postgres -c 'config_file=/etc/postgresql.conf'