app.shutdown does not work with ui.run_with

[MuuXB]

Description

import uvicorn
from fastapi import FastAPI
from nicegui import ui, app

server = FastAPI()


def init() -> None:
    @ui.page("/")
    def main():
        ui.button('shutdown', on_click=app.shutdown)

    ui.run_with(server)


init()

if __name__ == "__main__":
    uvicorn.run(server, host="127.0.0.1", port=7778)

My app is started using fastapi. I want to stop the service through a button. How to do it?
app.shutdown will report an exception.

[python-and-fiction]

inspired by encode/uvicorn#1103 (comment)
you could do same as:

import uvicorn
from fastapi import FastAPI
from nicegui import ui, app
import signal

server = FastAPI()

def init() -> None:
    @ui.page("/")
    def main():
        ui.button('shutdown', on_click=lambda: signal.raise_signal(signal.SIGINT))
    ui.run_with(server)

init()

if __name__ == "__main__":
    uvicorn.run(server, host="127.0.0.1", port=7778)

[falkoschindler]

Thanks for reporting this issue, @MuuXB!
When running with an existing FastAPI app, there seems to be no Server.instance. We should either find a reference to the uvicorn server or find another way to shutdown the app.