简而言之，我问题是我无法访问在docker contrainer中运行的flask应用程序。
我有 flask 应用程序

@app.route('/')
def home():
    return "test"

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)

我的dockerfile

# start by pulling the python image
FROM python:3.8

WORKDIR /app
# copy the requirements file into the image
COPY requirements.txt .

RUN pip install -r requirements.txt

# copy every content from the local file to the image
COPY . /app

CMD [ "python", "app.py" ]

我的docker compose

version: '3'
services:
  python-backend:
    build: ./LAB3
    container_name: python-backend
    ports:
      - "5000:5000"

文件夹结构labDocker（包含docker compose）-〉LAB 3（包含dockerfile）
当我运行我的应用程序是启动没有任何错误，请参阅下面的日志

WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.

 * Running on http://127.0.0.1:5000

Press CTRL+C to quit

 * Serving Flask app 'app' (lazy loading)

 * Environment: production

   WARNING: This is a development server. Do not use it in a production deployment.

   Use a production WSGI server instead.

 * Debug mode: off

当我试图通过 Postman 发送请求时，我收到错误：

GET http://127.0.0.1:5000/
Error: socket hang up
Request Headers
User-Agent: PostmanRuntime/7.31.3
Accept: */*
Postman-Token: e54441e3-9ec4-427c-8202-e09f5cd92500
Host: 127.0.0.1:5000
Accept-Encoding: gzip, deflate, br
Connection: keep-alive

我在这个论坛上浏览了几个有类似问题的主题，但都没有解决我的问题，如果你有任何建议，请让我知道
docker ps -a

CONTAINER ID   IMAGE                              COMMAND                  CREATED          STATUS                     PORTS                    NAMES
ae6ad71c8542   labdocker_python-backend           "python app.py"          15 minutes ago   Up 15 minutes              0.0.0.0:5000->5000/tcp   python-backend