ngroktunnelfixture

class NgrokTunnel:
    def __init__(self, port: str):
        assert find_executable(
            "ngrok"
        ), "ngrok command must be installed, see https://ngrok.com/"
        self.port = port

    def start(self, ngrok_die_check_delay: float = 0.5) -> Optional[str]:
        logger.debug(f"Starting ngrok tunnel for port {self.port}")
        pattern = r"^.*addr=(?P<addr>http://localhost:(?P<port>\d+)) url=(?P<ngrokurl>https://(?P<ngroksubdomain>.*)\.ngrok\.io)$"

        self.ngrok = subprocess.Popen(
            [
                "ngrok",
                "http",
                self.port,
                "--log",
                "stdout",
            ],
            stdout=subprocess.PIPE,
            bufsize=1,
            universal_newlines=True,
        )
        found = False
        ngrokurl = None
        while not found:
            for line in self.ngrok.stdout:
                # logger.debug(line, end="")
                m = re.match(pattern, line)
                if m is not None:
                    # addr = m.group("addr")
                    # port = m.group("port")
                    ngrokurl = m.group("ngrokurl")
                    # ngroksubdomain = m.group("ngroksubdomain")
                    found = True
                    break
        # See that we don't instantly die
        time.sleep(ngrok_die_check_delay)
        assert self.ngrok.poll() is None, "ngrok terminated abrutly"
        return ngrokurl

    def stop(self) -> None:
        """Tell ngrok to tear down the tunnel.

        Stop the background tunneling process.
        """
        self.ngrok.terminate()


@pytest.fixture(scope="session", autouse=True)
def ngrokurl_subscriber() -> Iterable[Optional[str]]:
    ngrok_subscriber = NgrokTunnel("5002")
    url = ngrok_subscriber.start()
    yield url
    ngrok_subscriber.stop()
    
@pytest.fixture(scope="session")
async def subscriber_server(subscriber_test_app: FastAPI) -> AsyncIterator[Server]:
    config = Config(app=subscriber_test_app, port=5002)
    server = Server(config=config)
    task = asyncio.ensure_future(server.serve())
    try:
        while not server.started:
            await asyncio.sleep(0.0001)
        yield server
    finally:
        logger.debug("END SUBSCRIBER SERVER")
        server.should_exit = True
        await task