[网络协议]django2.2和channels2.1.7实现websocket通信

环境：
django2.2.24
channels2.1.7
项目名mysite

注册channels

# settings.py
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'app',
    'channels',
]

配置ASGI_APPLICATION

# settings.py
ASGI_APPLICATION = 'mysite.routing.application'

mysite下创建routing.py文件

# routing.py
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.auth import AuthMiddlewareStack
import app.routing

application = ProtocolTypeRouter({
    'websocket': AuthMiddlewareStack(
        URLRouter(app.routing.urlpatterns)
    ),
})

app下创建routing.py文件

from django.urls import path
from .consumers import Test

urlpatterns = [
    path('ws/test', Test),
]

app下创建consumers.py文件

from channels.generic.websocket import WebsocketConsumer


class Test(WebsocketConsumer):
    def connect(self):
        self.accept()
        print("连接来了")
        for i in range(10):
            self.send(str(i))
        self.close()

    def disconnect(self, code):
        print("连接断开")

    def receive(self, text_data=None, bytes_data=None):
        print(text_data)
        self.send(text_data)

===========================================

实现聊天

聊天实现需要用到Channels Layer
redis做Channels Layer（官方推荐）

安装channels-redis

pip install channels_redis==2.3.3

在setting.py中添加配置

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'channels_redis.core.RedisChannelLayer', # redis做channels layer
        'CONFIG': {
            "hosts": ["redis://:123456@127.0.0.1:6379/3"],
        },
    },
}

CHANNEL_LAYERS的其它配置配置方案
内存做channels layer

CHANNEL_LAYERS = {
    "default": {
        "BACKEND": "channels.layers.InMemoryChannelLayer",
    }
}

consumers.py中的简单使用

class ChatConsumer(WebsocketConsumer):

    def connect(self):
        self.room_name = "kuyer" # 所有连接都在kuyer分组
        async_to_sync(self.channel_layer.group_add)(self.room_name, self.channel_name)  # 注册channel_name
        self.accept()

    def disconnect(self, code):
        async_to_sync(self.channel_layer.group_discard)(self.room_name, self.channel_name) # 移除

    def receive(self, text_data=None, bytes_data=None):
        async_to_sync(self.channel_layer.group_send)(
            self.room_name,
            {
                'type': 'chat_message',
                'message': text_data
            }
        )

    def chat_message(self, event):
        message = '微聊：' + event['message']
        self.send(message)