Telnet 连接被 docker 拒绝

Question

我正在尝试在我的 docker flask 项目中使用 telnet 来使用 rdb 调试 celery 任务。

为此，我在我的 dockerfile 中安装了 telnet，然后为了测试它，我使用：

docker-compose exec web bash

，web 基本上是我的烧瓶服务器，然后运行

flask shell

进行测试。

然后我运行

from project.users.tasks import divide

，将我的测试任务划分为以下代码：

@shared_task
def divide(x, y):
    rdb.set_trace()

    import time
    time.sleep(5)
    return 10*x / y

似乎一切都很好，因为当我运行

divide.delay(1, 2)

时，我收到：

Remote Debugger:6899: Ready to connect: telnet 127.0.0.1 6899

Type `exit` in session to continue.

Remote Debugger:6899: Waiting for client...

但我的问题是，当我进入

docker-compose exec celery_worker bash

并尝试运行

telnet 127.0.0.1 6899

时，我收到：

Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused

有人知道我现在做错了什么吗？因为我真的不明白这里的问题是什么......

提前致谢！

编辑：如果我回到 docker-compose exec web bash 并运行 telnet 而不是其他地方，则与 telnet 的连接有效。

顺便说一句，我的撰写文件如下：

version: '3.8'

services:
  web:
    build:
      context: .
      dockerfile: ./compose/local/flask/Dockerfile
    image: flask_celery_example_web
    # '/start' is the shell script used to run the service
    command: /start
    # this volume is used to map the files and folders on the host to the container
    # so if we change code on the host, code in the docker container will also be changed
    volumes:
      - .:/app
    ports:
      - 5010:5000
    env_file:
      - .env/.dev-sample
    environment:
      - FLASK_APP=app
    depends_on:
      - redis
      - db

  db:
    image: postgres:14-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    environment:
      - POSTGRES_DB=flask_celery
      - POSTGRES_USER=flask_celery
      - POSTGRES_PASSWORD=flask_celery

  redis:
    image: redis:7-alpine

  celery_worker:
    build:
      context: .
      dockerfile: ./compose/local/flask/Dockerfile
    image: flask_celery_example_celery_worker
    command: /start-celeryworker
    volumes:
      - .:/app
    env_file:
      - .env/.dev-sample
    environment:
      - FLASK_APP=app
    depends_on:
      - redis
      - db

  celery_beat:
    build:
      context: .
      dockerfile: ./compose/local/flask/Dockerfile
    image: flask_celery_example_celery_beat
    command: /start-celerybeat
    volumes:
      - .:/app
    env_file:
      - .env/.dev-sample
    environment:
      - FLASK_APP=app
    depends_on:
      - redis
      - db

  flower:
    build:
      context: .
      dockerfile: ./compose/local/flask/Dockerfile
    image: flask_celery_example_celery_flower
    command: /start-flower
    volumes:
      - .:/app
    env_file:
      - .env/.dev-sample
    environment:
      - FLASK_APP=app
    ports:
      - 5557:5555
    depends_on:
      - redis
      - db

volumes:
  postgres_data:

还有我的 Dockerfile ：

FROM python:3.9-slim-buster

ENV PYTHONUNBUFFERED 1
ENV PYTHONDONTWRITEBYTECODE 1

RUN apt-get update \
  # dependencies for building Python packages
  && apt-get install -y build-essential \
  # psycopg2 dependencies
  && apt-get install -y libpq-dev \
  # Additional dependencies
  && apt-get install -y telnet netcat \
  # cleaning up unused files
  && apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false \
  && rm -rf /var/lib/apt/lists/*

# Requirements are installed here to ensure they will be cached.
COPY ./requirements.txt /requirements.txt
RUN pip install -r /requirements.txt

COPY ./compose/local/flask/entrypoint /entrypoint
RUN sed -i 's/\r$//g' /entrypoint
RUN chmod +x /entrypoint

COPY ./compose/local/flask/start /start
RUN sed -i 's/\r$//g' /start
RUN chmod +x /start

COPY ./compose/local/flask/celery/worker/start /start-celeryworker
RUN sed -i 's/\r$//g' /start-celeryworker
RUN chmod +x /start-celeryworker

COPY ./compose/local/flask/celery/beat/start /start-celerybeat
RUN sed -i 's/\r$//g' /start-celerybeat
RUN chmod +x /start-celerybeat

COPY ./compose/local/flask/celery/flower/start /start-flower
RUN sed -i 's/\r$//g' /start-flower
RUN chmod +x /start-flower

WORKDIR /app

ENTRYPOINT ["/entrypoint"]