为什么 Flask_ngrok 在 Colab 上出现 ConnectionRefusedError: [Errno 111] Connection returned 错误

Question

我试图通过 colab 烧瓶。以下是我在谷歌Colab上的代码：

from flask import Flask
!pip install flask_ngrok
from flask_ngrok import run_with_ngrok

app = Flask(__name__)
run_with_ngrok(app) 

@app.route("/")
def hello():
    return "Hello World!"

if __name__ == '__main__':
    app.run()

它来自这个例子（顺便说一句，这个笔记本本身有一个不同的模块错误），但我不断得到

Exception in thread Thread-11:
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 174, in _new_conn
    conn = connection.create_connection(
  File "/usr/local/lib/python3.10/dist-packages/urllib3/util/connection.py", line 95, in create_connection
    raise err
  File "/usr/local/lib/python3.10/dist-packages/urllib3/util/connection.py", line 85, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [Errno 111] Connection refused

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connectionpool.py", line 703, in urlopen
    httplib_response = self._make_request(
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connectionpool.py", line 398, in _make_request
    conn.request(method, url, **httplib_request_kw)
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 244, in request
    super(HTTPConnection, self).request(method, url, body=body, headers=headers)
  File "/usr/lib/python3.10/http/client.py", line 1283, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/lib/python3.10/http/client.py", line 1329, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.10/http/client.py", line 1278, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/lib/python3.10/http/client.py", line 1038, in _send_output
    self.send(msg)
  File "/usr/lib/python3.10/http/client.py", line 976, in send
    self.connect()
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 205, in connect
    conn = self._new_conn()
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 186, in _new_conn
    raise NewConnectionError(
urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPConnection object at 0x7f0594e70ca0>: Failed to establish a new connection: [Errno 111] Connection refused

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/requests/adapters.py", line 440, in send
    resp = conn.urlopen(
  File "/usr/local/lib/python3.10/dist-packages/urllib3/connectionpool.py", line 787, in urlopen
    retries = retries.increment(
  File "/usr/local/lib/python3.10/dist-packages/urllib3/util/retry.py", line 592, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='localhost', port=4040): Max retries exceeded with url: /api/tunnels (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f0594e70ca0>: Failed to establish a new connection: [Errno 111] Connection refused'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 1378, in run
    self.function(*self.args, **self.kwargs)
  File "/usr/local/lib/python3.10/dist-packages/flask_ngrok.py", line 70, in start_ngrok
    ngrok_address = _run_ngrok()
  File "/usr/local/lib/python3.10/dist-packages/flask_ngrok.py", line 35, in _run_ngrok
    tunnel_url = requests.get(localhost_url).text  # Get the tunnel information
  File "/usr/local/lib/python3.10/dist-packages/requests/api.py", line 75, in get
    return request('get', url, params=params, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/requests/api.py", line 61, in request
    return session.request(method=method, url=url, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/requests/sessions.py", line 529, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/local/lib/python3.10/dist-packages/requests/sessions.py", line 645, in send
    r = adapter.send(request, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/requests/adapters.py", line 519, in send
    raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='localhost', port=4040): Max retries exceeded with url: /api/tunnels (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f0594e70ca0>: Failed to establish a new connection: [Errno 111] Connection refused'))

谁能告诉我问题是什么？我正在遵循教程，他们给了我类似的答案，所有这些都导致了我的错误。

我期待像所有教程所示的 ngrok 链接。

Answer 1

我自己也遇到了完全相同的问题。事实证明，您只需要拥有一个 ngrok 帐户并获取身份验证令牌即可。很容易修复。

1. 访问 ngrok 网站并创建一个帐户： https: //dashboard.ngrok.com/login

2. 在左侧菜单中，将有一个“您的 Authtoken”选项。单击它，将显示 authtoken 供您复制。

3. 在您的 google colab 笔记本中，在 pip install 命令正下方的代码开头包含身份验证令牌。确保包含“！” 在它之前：

!pip install flask-ngrok
!pip install pyngrok==4.1.1
!ngrok authtoken ######YOUR AUTHTOKEN GOES HERE#####

安装软件包后，您应该在底部看到如下消息：

这表明您的 authtoken 已成功保存。

4. 再次运行启动 Flask 应用程序的单元，服务器应该正在运行并包含指向您的特定 ngrok url 的链接。

我也没有将这部分包含在我自己的代码中：

if __name__ == '__main__':
    app.run()

本教程对我有帮助： https: //youtu.be/0dYsZt8-nXk