docker - docker-compose:在 `php-fpm`结束之前，有什么方法可以阻止 `db`启动吗？

Question

我有以下docker-compose.yml文件:

version: '2'
services:
    db:
        image: mysql
        environment:
            MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
            MYSQL_DATABASE: ${MYSQL_DATABASE}
            MYSQL_USER: ${MYSQL_USER}
            MYSQL_PASSWORD: ${MYSQL_PASSWORD}
        volumes:
            - sql_data:/var/lib/mysql
    httpd:
        build: docker/httpd
        ports:
            - "80:80"
        volumes_from:
            - php-fpm
    php-fpm:
        build: docker/php-fpm
        depends_on:
            - db
volumes:
    sql_data:
        external: true

容器php-fpm应该运行一些脚本来创建模式，并且仅在db已启动并且数据库已成功创建的情况下才加载假数据。当前docker-compose up -d --build --force-recreate正在执行以下操作:

使用默认驱动程序

创建网络dockerpyrocms_default

建筑物php-fpm

建筑物httpd

创建dockerpyrocms_db_1

创建dockerpyrocms_php-fpm_1

创建dockerpyrocms_httpd_1

但是由于尚未创建数据库，因此dockerpyrocms_php-fpm_1退出并带有代码`，原因是它可以连接到数据库:

php-fpm_1  |   [Illuminate\Database\QueryException]   
php-fpm_1  |   SQLSTATE[HY000] [2002] Connection refused (SQL: select * from information_schema.tables where table_schema = pyrocms and table_name = default_migrations)  
php-fpm_1  |   [Doctrine\DBAL\Driver\PDOException]
php-fpm_1  |   SQLSTATE[HY000] [2002] Connection refused

显然，“depends_on”是没有用的，因为Docker不知道容器何时“就绪”，它只知道容器何时启动。

我可以就此获得一些建议吗？有关如何解决此问题的任何想法？

这是带有文件和说明的the repo。

Note: Such problem only happen if MySQL image was already pulled and there wasn't any changes. If you run this for first time then it'll works if you run in a second time it will fails.

Answer 1

我在Docker Compose本身中找到了它:

With Compose 1.10, it is now possible to indicate you want a dependency to wait for another container to be “healthy” (i.e. its healthcheck advertises a successful state) before starting.

例如:

version: '2.1'
services:
  web:
    build: .
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_started
  redis:
    image: redis
  db:
    image: redis
    healthcheck:
      test: "exit 0"

现在我的docker-compose.yml看起来像:

version: '2.1'
services:
    db:
        image: mysql
        healthcheck:
            test: "exit 0"
        environment:
            MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD}
            MYSQL_DATABASE: ${MYSQL_DATABASE}
            MYSQL_USER: ${MYSQL_USER}
            MYSQL_PASSWORD: ${MYSQL_PASSWORD}
        volumes:
            - sql_data:/var/lib/mysql
    httpd:
        build: docker/httpd
        ports:
            - "80:80"
        volumes_from:
            - php-fpm
    php-fpm:
        build: docker/php-fpm
        depends_on:
            db:
                condition: service_healthy
volumes:
    sql_data:
        external: true

它按预期工作。更多信息here和here。