How can I start a SocketIO server and have it be listening in the background while I continue to execute code on the main thread?
Right now I am using the package python-socketio. I have also testedflask-socketio which using python-socketio anyway.
https://python-socketio.readthedocs.io/en/latest/server.html
What I've mostly tried is starting the server with sio.start_background_task.
For example:
class SocketIOServer(socketio.AsyncNamespace):
def __init__(self):
super().__init__()
self.sio = socketio.AsyncServer()
self.sio.register_namespace(self)
self.app = web.Application()
self.sio.attach(self.app)
self.task = None
def run(self):
web.run_app(self.app, port=8080)
def start(self):
self.task = self.sio.start_background_task(self.run)
I tried the above and multiple variations like using Flask, Tornado, etc.
To be more clear this is basically what I want to do:
if __name__ == '__main__':
# ...
# start app, e.g. -> web.run_app(self.app, port=8080)
# I want to continue to execute code here
I don't fully understand how everything is working, am I asking a stupid question?
The problem is as you described it. You do not fully understand how everything works.
The most important thing that you are missing is that the python-socketio package is not a web server. This package just implements the Socket.IO logic, but you have to add a web server through which your Socket.IO code is available.
From the code that you included in your question, it appears that you have selected to attach the Socket.IO code to a web application built with the aiohttp framework, and use its own web server. Correct?
Then the real question that you have is how to run the aiohttp web server in a non-blocking way.
And it runs out that aiohttp has information on this in their documentation: https://docs.aiohttp.org/en/stable/web_advanced.html#application-runners. The example they have does this:
runner = web.AppRunner(app)
await runner.setup()
site = web.TCPSite(runner, 'localhost', 8080)
await site.start() # <-- starts the server without blocking
# you can do whatever you want here!