Deny HTTP requests (ws only server)

[realsuayip]

Say I want to have setup where I handle http requests with gunicorn and websocket related stuff with daphne (each in different containers).

It seems that daphne can switch/fallback into http requests using the asgi app entry; I'm looking to change this behavior since I only want this server to handle websocket requests.

Is it possible to deny HTTP requests in this case? Does this make sense to you?

[carltongibson]

Ideally your load-balancer (nginx for example) correctly routes the different request types to the correct app.

You could though define an http handler in a ProtocolTypeRouter in order to reject any HTTP requests that did arrive.

As of v3 ProtocolTypeRouter defines a default http handler if you don't provide one, but will not do that from v4 (next main version) — so HTTP requests would result in a ValueError, that would get converted to 500 — so you might want to define a dummy 4xx type handler if you think such requests may arrive at your application.

I hope that helps.

[realsuayip]

That makes sense. Thank you so much.

[karolyi]

I couldn't configure nginx not to allow HTTP requests to the WS backend and I kept getting the ValueErrors constantly. Here's how I solved it:

This is asgi.py:

import os

from channels.routing import ProtocolTypeRouter
from channels.security.websocket import AllowedHostsOriginValidator
from django import setup
from django.conf import settings
from django.core.handlers.asgi import ASGIHandler
from django.http.response import HttpResponsePermanentRedirect

# This needs to be run first before imports from the project can be done
setup()

from yourproject.routing import ws_urls  # noqa: E402

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'yourproject.settings')
application_mapping = dict(
    websocket=AllowedHostsOriginValidator(application=ws_urls))

if settings.DEBUG:
    from django.core.asgi import get_asgi_application
    http_handler = get_asgi_application()
    application_mapping.update(http=http_handler)  # type: ignore
else:
    class RedirectAllHandler(ASGIHandler):
        async def get_response_async(self, request):
            return HttpResponsePermanentRedirect(redirect_to='/')
    application_mapping.update(http=RedirectAllHandler())  # type: ignore


application = ProtocolTypeRouter(application_mapping=application_mapping)

You're all welcome.