Django now working channels with ASGI + WSGI in Heroku - django

Question

I am trying to setup a Django + Heroku app with Channels (V.2).
I tried to follow all the tutorial but most of them are not updated.
App must use WSGI for HTTP request and ASGI for websockets requests.
So far I found that it is almost working, the last missing piece is for the websockets endpoints to be visible for web app.
At this point whenever I try to create a new websocket:
Error during WebSocket handshake: Unexpected response code: 404
Here is the Settings:
ASGI_APPLICATION = 'app_xxx.routing.application'
ASGI_THREADS = 5
WSGI_APPLICATION = 'app_xxx.wsgi.application'
CHANNEL_LAYERS = {
"default": {
"BACKEND": "channels_redis.core.RedisChannelLayer",
"CONFIG": {
'hosts': [os.environ.get('REDIS_URL')],
},
},
}
Here is the Procfile:
web: gunicorn app_xxx.wsgi --log-file -
web2: daphne app_xxx.asgi:channel_layer --port $PORT --bind 0.0.0.0 -v2
worker: python manage.py runworker channel_layer -v2
Here is the asgi:
import os
from channels.layers import get_channel_layer
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "app_xxx.settings")
channel_layer = get_channel_layer()
Here is the routing:
from channels.routing import ProtocolTypeRouter, URLRouter, ChannelNameRouter
from django.urls import path
from apps.booking.consumers import BookingConsumer
application = ProtocolTypeRouter({
"websocket": URLRouter([
path('ws/booking_review/<room_name>', BookingConsumer),
]),
})

Answer 1

You're supposed to run the ASGI application, not channel layer. Your ASGI_APPLICATION setting should point to routing.py or you can move its contents to asgi.py and point to it. With your current configuration, your Procfile should look like this:
web: gunicorn app_xxx.wsgi --log-file -
web2: daphne app_xxx.routing:application --port $PORT --bind 0.0.0.0 -v2
worker: python manage.py runworker channel_layer -v2
Check the docs deployment page for more details