Here, I need to connect another channel using web sockets in django channels. I can't connect to the another channel, it showing error like this.
consumers.py
import json
from asgiref.sync import async_to_sync
from channels.generic.websocket import WebsocketConsumer
class ChatConsumer(WebsocketConsumer):
    def connect(self):
        self.room_name = self.scope['url_route']['kwargs']['room_name']
        self.room_group_name = 'chat_%s' % self.room_name
        # Join room group
        async_to_sync(self.channel_layer.group_add)(
            self.room_group_name,
            self.channel_name
        )
        self.accept()
    def disconnect(self, close_code):
        # Leave room group
        async_to_sync(self.channel_layer.group_discard)(
            self.room_group_name,
            self.channel_name
        )
    # Receive message from WebSocket
    def receive(self, text_data):
        text_data_json = json.loads(text_data)
        message = text_data_json['message']
        # Send message to room group
        async_to_sync(self.channel_layer.group_send)(
            self.room_group_name,
            {
                'type': 'chat_message',
                'message': message
            }
        )
    # Receive message from room group
    def chat_message(self, event):
        message = event['message']
        # Send message to WebSocket
        self.send(text_data=json.dumps({
            'message': message
        }))
routing.py*(In django project)*
from channels.auth import AuthMiddlewareStack
from channels.routing import ProtocolTypeRouter, URLRouter
import chat.routing
application = ProtocolTypeRouter({
    
    'websocket': AuthMiddlewareStack(
        URLRouter(
            chat.routing.websocket_urlpatterns
        )
    ),
})
routing.py*(In chat app)*
from django.urls import re_path
from .consumers import ChatConsumer
websocket_urlpatterns = [
    re_path(r'ws/chat/(?P<room_name>\w+)/$',ChatConsumer),
]
views.py
from django.shortcuts import render
def index(request):
    return render(request, 'chat/index.html')
def room(request, room_name):
    return render(request, 'chat/room.html', {
    'room_name': room_name
    })
urls.py*(In chat App)*
 
from django.contrib import admin
from django.urls import path
from  .views import index,room
app_name = 'chat'
urlpatterns = [
   
     path('', index, name='index'),
     path('<str:room_name>/', room, name='room'),
]
urls.py*(In main project folder)*
 
from django.contrib import admin
from django.urls import path,include
from chat.views import index
urlpatterns = [
    path('admin/', admin.site.urls),
     path('chat/',include('chat.urls',namespace = 'chat')),
]
settings.py
 
from pathlib import Path
# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent
# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/
# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = '_94me+sc-lcgo-eo1zrf%!t!q8$rk2b)%e-58u^h2d#v8gzk#j'
# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True
ALLOWED_HOSTS = []
# Application definition
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'channels',
    'chat'
]
MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]
ROOT_URLCONF = 'justchat.urls'
TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]
WSGI_APPLICATION = 'justchat.wsgi.application'
ASGI_APPLICATION = 'justchat.routing.application'
CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer',
        'CONFIG': {
            "hosts": [('127.0.0.1', 6379)],
        },
    },
}
# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': str(BASE_DIR / 'db.sqlite3'),
    }
}
# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators
AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]
# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/
LANGUAGE_CODE = 'en-us'
TIME_ZONE = 'UTC'
USE_I18N = True
USE_L10N = True
USE_TZ = True
# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/
STATIC_URL = '/static/'
You forgot to run redis server.
In official tutorial it is done via docker image. At first, you need to install docker. After that run redis image at 6379 port:
docker run -p 6379:6379 -d redis:5
Update:
If you are using Windows, some troubles may arise. django-channels comes packaged with redis and in-memory channel layers. Generally, in development you don't have to use redis, just redefine channel layers backend option:
settings.py
CHANNEL_LAYERS = {
    "default": {
        "BACKEND": "channels.layers.InMemoryChannelLayer"
    }
}
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With