Mocking web server in Component/Functional testing in Python

Question

I'm trying to write some component/functional test for my application writed in C++. The application communicates with several http servers. For test I would like to mock these servers to easy handle bad path eg timeouts. Could you recommend me some python package to do this?

OR

I have tried to use Flask to mock my Http server. My problem with flask is that I don't know how to run it in backgroun non blocking mode. I have trying: Using thread and lamba

  class MyServerMock:
    def __init__(self, port=5000):
        super().__init__()
        self.port = port
        self.app = Flask(__name__)
        self.url = "http://localhost:{}".format(self.port)

        self.app.add_url_rule("/path/to/function", view_func=self.function, methods=['POST'])

    
    def function(body):
        pass

    def shutdown_server(self):
        self.app.do_teardown_appcontext()

    def run(self):
        self.thread = Thread(target=lambda: self.app.run(port=self.port, debug=False, use_reloader=False)).start()

this solution works, but after execution test cases test script is hanging in Flask and I don't know how to proper shutdown Flask.

Thank you from advance for you help.

EDIT 1: How I use this Flask code:

import MyServerMock
import pytest

def test_example():
    mock = MyServerMock(port=6500)
    mock.run()
 
    # testing stuf

    mock.shutdown()
    assert 1 == 2

I thinking about doing fixture with this mocking server

Answer 1

For a Unix solution, run your test server(s) in the background using nohup

nohup python server_1.py > server_1.log 2>&1 & 
echo $! > pid_server_1.txt

Run some test modules, for example, with a Makefile

make test

When tests are done, kill the server(s) using the saved pid

kill $(cat pid_server_1.txt)