Uvicorn cannot be shutdown programmatically

There is no documented way to shutdown uvicorn in python:

ex:

instance = uvicorn.run("example:app", host="127.0.0.1", port=5000, log_level="info")
instance.shutdown()

How do we shutdown uvicorn?

[florimondmanca]

Hi,

Not documented indeed, but a multithreaded approach should do…

import contextlib
import time
import threading
import uvicorn

class Server(uvicorn.Server):
    def install_signal_handlers(self):
        pass

    @contextlib.contextmanager
    def run_in_thread(self):
        thread = threading.Thread(target=self.run)
        thread.start()
        try:
            while not self.started:
                time.sleep(1e-3)
            yield
        finally:
            self.should_exit = True
            thread.join()

config = Config("example:app", host="127.0.0.1", port=5000, log_level="info")
server = Server(config=config)

with server.run_in_thread():
    # Server started.
    ...
# Server stopped.

Very handy to run a live test server locally using a pytest fixture…

# conftest.py
import pytest

@pytest.fixture(scope="session")
def server():
    server = ...
    with server.run_in_thread():
        yield

[plazmakeks]

I’m following @florimondmanca s approach to run pact tests on the provider side. However when using this i get the following error from uvicorn’s Server.run method:

RuntimeError: There is no current event loop in thread 'Thread-7'.

Any idea on that? Happens with python 3.6.9 as well as 3.7.7.

another edit:

I got it to work using

config = Config("example:app", host="127.0.0.1", port=5000, log_level="info", loop="asyncio")