"Shelf服务器容器访问MySQL Docker容器时出现SocketException异常"

语境

I am trying to create a Dart server with the library shelf.
I want it a bit scalable in order to get to production when my project will be ready.

为了便于产品发布，我决定使用Docker以便于部署.

DART盘架服务器

这是我的文档文件:

# Use latest stable channel SDK.
FROM dart:stable AS build

# Resolve app dependencies.
WORKDIR /app
COPY pubspec.* ./
RUN dart pub get

# Copy app source code (except anything in .dockerignore) and AOT compile app.
COPY . .
RUN dart compile exe bin/server.dart -o bin/server

# Build minimal serving image from AOT-compiled `/server`
# and the pre-built AOT-runtime in the `/runtime/` directory of the base image.
FROM scratch
COPY --from=build /runtime/ /
COPY --from=build /app/bin/server /app/bin/

# Start server.
EXPOSE 8080
CMD ["/app/bin/server"]

(它是Shelf自述文件提供的基本dockerfile)

Docker-使用数据库编写文件

Now, I need a database.
I put it in a separate container.
Here is my docker-compose.yaml file :

version: "3.7"
services:
  db:
    restart: always
    image: mysql
    environment:
      MYSQL_USER: admin
      MYSQL_PASS: secret
      MYSQL_ROOT_PASSWORD: secret
      MYSQL_PASSWORD: secret
      MYSQL_DATABASE: mydatabase
    # volumes:
    #   - toast-datavolume:/var/lib/mysql
    ports:
      - "3306:3306"
    networks:
      - mynetwork

  server:
    build: .
    ports:
      - "8000:8080"
    depends_on:
      - db
    environment:
      - MYSQL_HOST=db
    links:
      - db:mysql
    networks:
      - mynetwork

networks:
  mynetwork:
# volumes:
#   toast-datavolume:

(我注释掉了持久性部分，因为我只想让它先起作用)

DART代码

最后，下面是负责连接的DART代码:

try {
  print('try');
  var settings = ConnectionSettings(
    host: 'db',
    port: 3306,
    user: 'admin',
    password: 'secret',
    db: 'mydatabase',
    timeout: Duration(seconds: 30),
  );
  var conn = await MySqlConnection.connect(settings);
  var result = await conn.query('insert into users (name, email, age) values (?, ?, ?)', ['Bob', 'bob@bob.com', 25]);

  return 1;
} catch (exception) {
  print(exception);
  return -1;
}

误差率

现在，当我启动容器时，一切都正常进行.然而，当我try 启动这部分代码时(使用cURL请求，这里由上面的一些代码重定向)，下面是我的异常(在server个docker日志(log)上):

2023-06-07 11:45:14 2023-06-07T09:45:14.465441  0:00:00.011712 POST    [400] /register
2023-06-07 11:46:42 try
2023-06-07 11:46:42 SocketException: Broken pipe (OS 误差率: Broken pipe, errno = 32), address = db, port = 33206

The POST line shows my curl command.
The second line is my print('try') line.

以下是我已经try 过的:

• 删除docker-compose.yaml中的network以使用默认网络
• 在我的DART代码中使用mysql://db:3306作为主机
• 从本地登录到我的MySQL容器(工作正常，所以问题出在DART服务器和MySQL服务器之间的连接)
• 我try 了很多我不记得的事情，因为我花了两天的时间才做到了这一点.

谢谢你的帮助！