mysql - Docker:MySQL准备就绪时， “wait-for-it”脚本无法启动应用程序

Question

MySQL服务准备好接收连接后，我将使用Docker-Compose和wait-for-it从Node.js启动后端。我的问题是脚本无法实现连接本身的准备。如果我将超时设置为20s，则可以使它正常工作，因为届时MySQL将在那时运行，但是在不同的环境下可能会发生变化，如果在特定环境下花费更多时间，则该应用程序将崩溃。我希望它定期检查它，因为我认为这是正确的事情。

这是我的docker-compose.yml:

version: "3.8"

services:

  app:
    image: pfmc
    ports:
      - 4005:4005
    working_dir: /usr/src/app
    command: sh -c './wait-for-it.sh -t 0 db:3306 -- npm start'
    environment: 
      MYSQL_ROOT_PASSWORD: pfmc123
      MYSQL_HOST: mysql
      MYSQL_USER: root
      MYSQL_PASSWORD: pfmc123
      MYSQL_DATABASE: pfmc

  mysql:
    image: mysql:5
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    volumes:
      - ./db-startup:/docker-entrypoint-initdb.d
    environment:
      MYSQL_ROOT_PASSWORD: pfmc123
      MYSQL_DATABASE: pfmc

日志:

app_1    | wait-for-it.sh: waiting for db:3306 without a timeout
mysql_1  | 2020-05-25 19:59:58+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.30-1debian10 started.
mysql_1  | 2020-05-25 19:59:58+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
mysql_1  | 2020-05-25 19:59:58+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.30-1debian10 started.
mysql_1  | 2020-05-25 19:59:58+00:00 [Note] [Entrypoint]: Initializing database files

它停留在这一点上:

mysql_1  | 2020-05-25T20:00:08.243448Z 0 [Note] mysqld: ready for connections.
mysql_1  | Version: '5.7.30'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server (GPL)

非常感谢您的帮助。

Answer 1

您这里确实有一个问题:您的MySQL容器是一个名为mysql而不是db的服务，您应该将该服务改名为db或wait-for-it调用以轮询与mysql:3306的连接

总之，您的docker-compose.yml应该看起来像这样–我添加了带有说明@fixme的注释的修复程序:

version: "3.8"

services:

  app:
    image: pfmc
    ports:
      - 4005:4005
    working_dir: /usr/src/app
    command: sh -c './wait-for-it.sh -t 0 db:3306 -- npm start'
    environment: 
      MYSQL_ROOT_PASSWORD: pfmc123
      # A first @fixme is here 
      MYSQL_HOST: db
      MYSQL_USER: root
      MYSQL_PASSWORD: pfmc123
      MYSQL_DATABASE: pfmc

  # And a second @fixme is here
  db: 
    image: mysql:5
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    volumes:
      - ./db-startup:/docker-entrypoint-initdb.d
    environment:
      MYSQL_ROOT_PASSWORD: pfmc123
      MYSQL_DATABASE: pfmc