如何从主机查询 docker 容器？

编程问答 2022-05-26

问题描述

我在我的机器上的 docker 容器中运行一个服务器。我想从我的机器（主机）向容器内的服务器发送 HTTP 请求。当我在容器内使用 HTTP 发送 GET 请求时，它会检测到服务器。但是，如果我向容器的 IP 地址发送相同的请求（这次来自主机，容器外），它会告诉我：

Traceback (most recent call last):
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/requests/adapters.py",line 449,in send
    timeout=timeout
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/urllib3/connectionpool.py",line 727,in urlopen
    method,url,error=e,_pool=self,_stacktrace=sys.exc_info()[2]
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/urllib3/util/retry.py",line 410,in increment
    raise six.reraise(type(error),error,_stacktrace)
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/urllib3/packages/six.py",line 734,in reraise
    raise value.with_traceback(tb)
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/urllib3/connectionpool.py",line 677,in urlopen
    chunked=chunked,File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/urllib3/connectionpool.py",line 426,in _make_request
    six.raise_from(e,None)
  File "<string>",line 3,in raise_from
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/urllib3/connectionpool.py",line 421,in _make_request
    httplib_response = conn.getresponse()
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/http/client.py",line 1344,in getresponse
    response.begin()
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/http/client.py",line 306,in begin
    version,status,reason = self._read_status()
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/http/client.py",line 267,in _read_status
    line = str(self.fp.readline(_MAXLINE + 1),"iso-8859-1")
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/socket.py",line 589,in readinto
    return self._sock.recv_into(b)
urllib3.exceptions.ProtocolError: ('Connection aborted.',ConnectionResetError(104,'Connection reset by peer'))

或者这个：

Traceback (most recent call last):
  File "<stdin>",line 1,in <module>
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/requests/api.py",line 76,in get
    return request('get',params=params,**kwargs)
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/requests/api.py",line 61,in request
    return session.request(method=method,url=url,**kwargs)
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/requests/sessions.py",line 530,in request
    resp = self.send(prep,**send_kwargs)
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/requests/sessions.py",line 643,in send
    r = adapter.send(request,**kwargs)
  File "/home/user/miniconda3/envs/dl_project/lib/python3.7/site-packages/requests/adapters.py",line 516,in send
    raise ConnectionError(e,request=request)
requests.exceptions.ConnectionError: httpconnectionPool(host='172.17.0.2',port=8000): Max retries exceeded with url: /hello (Caused by NewConnectionError('<urllib3.connection.httpconnection object at 0x7f5312c54690>: Failed to establish a new connection: [Errno 111] Connection refused'))

这是我启动容器时使用的命令：

docker run -it --publish 8000:8000 my_server:v1

以及我为发送请求而运行的 Python 脚本：

import requests
print(requests.get("http://172.17.0.2:8000/hello").text

这是我用来查找容器 IP 地址的命令：

$ docker inspect d6c7d98b9fdd | grep IP
            "LinkLocalIPv6Address": "","LinkLocalIPv6PrefixLen": 0,"SecondaryIPAddresses": null,"SecondaryIPv6Addresses": null,"GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","IPAMConfig": null,

我知道 this 问题，但我没有使用 docker 文件来创建图像（我从 docker hub 中提取了它）所以答案对我没有帮助。我也找到了 this one，但它对我没有帮助。

预先感谢您的帮助。

解决方法

--publish 8000:8000 制定端口转发规则，将在主机端口 8000（左值）上接收到的数据包定向到容器的端口 8000（右值）。也就是说，您可以使用 <hostIpOrName>:8000 访问您的容器。在主机上，您可以使用 localhost:8000。

您最好不要在代码中使用容器 IP，因为它会经常更改。

还应注意，为了使此功能正常工作，您的后端应侦听环回 IP 地址（127.0.0.1 或类似地址）以外的其他内容。使用 0.0.0.0 允许应用程序接受来自任何 IP 的连接。对于 ray，这可以通过 serve.start(http_host="0.0.0.0") 实现。

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