如果$ docker-compose down使用以下命令运行，我似乎无法使MySQL数据持久化.yml

version: '2'
services:
  # other services

  data:
    container_name: flask_data
    image: mysql:latest
    volumes:
      - /var/lib/mysql
    command: "true"

  mysql:
    container_name: flask_mysql
    restart: always
    image: mysql:latest
    environment:
      MYSQL_ROOT_PASSWORD: 'test_pass' # TODO: Change this
      MYSQL_USER: 'test'
      MYSQL_PASS: 'pass'
    volumes_from:
      - data
    ports:
      - "3306:3306"

我的理解是，在我的data容器中，使用volumes: - /var/lib/mysql将其映射到我的本地计算机目录，在该目录中mysql将数据存储到容器中，由于这种映射，即使容器被破坏，数据也应持久存在。而且mysql容器只是进入db的客户端接口，可以看到本地目录，因为volumes_from:- data

编辑

改变了我.yml如下图所示，并创造了该目录./data，但现在当我运行docker-compose up --build的mysql容器不会开始抛出错误说

  data:
    container_name: flask_data
    image: mysql:latest
    volumes:
      - ./data:/var/lib/mysql
    command: "true"

  mysql:
    container_name: flask_mysql
    restart: always
    image: mysql:latest
    environment:
      MYSQL_ROOT_PASSWORD: 'test_pass' # TODO: Change this
      MYSQL_USER: 'test'
      MYSQL_PASS: 'pass'
    volumes_from:
      - data
    ports:
      - "3306:3306"


flask_mysql | mysqld: Can't create/write to file '/var/lib/mysql/is_writable' (Errcode: 13 - Permission denied)
flask_mysql | 2016-08-26T22:29:21.182144Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
flask_mysql | 2016-08-26T22:29:21.185392Z 0 [ERROR] --initialize specified but the data directory exists and is not writable. Aborting.