How to create a flask app within a google colab?

Question

I have been working on a machine learning model run through a sklearn pipeline in a google colab notebook and I am trying it to deploy it

I found this code common in all the existing tutorials.

     import tensorflow_datasets as tfds
     import tensorflow as tf
     from flask import Flask, jsonify, make_response, request
     from flask_ngrok import run_with_ngrok

     app = Flask(__name__)
     run_with_ngrok(app)

     padding_size = 1000
     model = pipeline

     print('Model and Vocabalory loaded.......')

     @app.route("/")
     def hello():
        return "I am alive!"


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

Upon running this in a colab cell, I get the following error.

Model and Vocabalory loaded.......

Serving Flask app 'main'

Debug mode: off INFO:werkzeug: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 INFO:werkzeug:Press CTRL+C to quit Exception in thread Thread-17: Traceback (most recent call last): File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 203, in _new_conn sock = connection.create_connection( File "/usr/local/lib/python3.10/dist-packages/urllib3/util/connection.py", line 85, in create_connection raise err File "/usr/local/lib/python3.10/dist-packages/urllib3/util/connection.py", line 73, in create_connection sock.connect(sa) ConnectionRefusedError: [Errno 111] Connection refused

The above exception was the direct cause of the following exception:

Traceback (most recent call last): File "/usr/local/lib/python3.10/dist-packages/urllib3/connectionpool.py", line 791, in urlopen response = self._make_request( File "/usr/local/lib/python3.10/dist-packages/urllib3/connectionpool.py", line 497, in _make_request conn.request( File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 395, in request self.endheaders() 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 243, in connect self.sock = self._new_conn() File "/usr/local/lib/python3.10/dist-packages/urllib3/connection.py", line 218, in _new_conn raise NewConnectionError( urllib3.exceptions.NewConnectionError: <urllib3.connection.HTTPConnection object at 0x79d8a4408b80>: Failed to establish a new connection: [Errno 111] Connection refused

The above exception was the direct cause of the following exception:

Traceback (most recent call last): File "/usr/local/lib/python3.10/dist-packages/requests/adapters.py", line 486, in send resp = conn.urlopen( File "/usr/local/lib/python3.10/dist-packages/urllib3/connectionpool.py", line 845, in urlopen retries = retries.increment( File "/usr/local/lib/python3.10/dist-packages/urllib3/util/retry.py", line 515, in increment raise MaxRetryError(_pool, url, reason) from reason  # type: ignore[arg-type] urllib3.exceptions.MaxRetryError: HTTPConnectionPool(host='localhost', port=4040): Max retries exceeded with url: /api/tunnels (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x79d8a4408b80>: 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 73, in get return request("get", url, params=params, **kwargs) File "/usr/local/lib/python3.10/dist-packages/requests/api.py", line 59, in request return session.request(method=method, url=url, **kwargs) File "/usr/local/lib/python3.10/dist-packages/requests/sessions.py", line 589, in request resp = self.send(prep, **send_kwargs) File "/usr/local/lib/python3.10/dist-packages/requests/sessions.py", line 703, 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 0x79d8a4408b80>: Failed to establish a new connection: [Errno 111] Connection refused'))

How do I proceed further?