第一步：
安装所需的pip包：channels，channels-redis
第二步：
修改settings.py添加相应配置,INSTALLED_APPS中加入channels，并加入CHANNEL_LAYERS
# channles
CHANNEL_LAYERS = {
'default': {
'BACKEND': 'channels_redis.core.RedisChannelLayer',
'CONFIG': {
"hosts": [(REDIS_HOST, REDIS_PORT)],
"symmetric_encryption_keys": [SECRET_KEY],
"prefix": 'cybercity:asgi',
},
},
}
第三步修改asgi的入口文件如下
import os
from django.core.asgi import get_asgi_application
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'x.settings')
django_asgi_app = get_asgi_application()
application = ProtocolTypeRouter({
'websocket': SessionMiddlewareStack(
URLRouter(
practice.routing.websocket_urlpatterns,
),
),
"http": django_asgi_app,
})
第四步添加consumer.py文件，放到对应的app里
(1)consumer.py的内容如下所示：
from channels.generic.websocket import AsyncJsonWebsocketConsumer
from practice import status
from practice.exceptions import ClientError
class NoticeConsumer(AsyncJsonWebsocketConsumer):
""" 考试事件消息推送 """
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# 定义消息推送房间
self.room = "notice"
self.is_closed = False
async def connect(self):
"""
Called when the websocket is handshaking as part of initial connection.
"""
# self.room_name = self.scope["url_route"]["kwargs"]["login_id"]
await self.accept()
async def receive_json(self, content, **kwargs):
"""
Called when we get a text frame. Channels will JSON-decode the payload
for us and pass it as the first argument.
"""
try:
command = content.get("command", None)
if command is None:
raise ClientError("COMMAND_IS_ACCESSARY")
if command == "join":
await self.join_room()
elif command == "leave":
await self.leave_room()
else:
raise ClientError("COMMAND_ERROR")
except ClientError as e:
await self.send_json({"error": e.code})
async def disconnect(self, code):
"""
Called when the WebSocket closes for any reason.
"""
self.is_closed = True
try:
await self.leave_room()
except ClientError:
pass
async def join_room(self):
"""
Called by receive_json when someone sent a join command.
"""
if status.NOTIFY_USERS_ON_ENTER_OR_LEAVE_ROOMS:
# 开启通知
await self.channel_layer.group_send(self.room, {
"type": "notice.join",
"room": self.room
})
# 加入消息组
await self.channel_layer.group_add(
self.room,
self.channel_name,
)
# 给连接的ws客户端发送确认消息
await self.send_json({
"join": self.room
})
async def leave_room(self):
"""
Called by receive_json when someone sent a leave command.
"""
if status.NOTIFY_USERS_ON_ENTER_OR_LEAVE_ROOMS:
await self.channel_layer.group_send(
self.room, {
"type": "notice.leave",
"room": self.room
})
# 离开消息组
await self.channel_layer.group_discard(
self.room,
self.channel_name,
)
# 给连接的ws客户端发送确认消息
# 如果ws客户端连接断开则不发送确认消息
if not self.is_closed:
await self.send_json({
"leave": self.room,
})
async def notice_join(self, event):
"""
Called when someone has joined our chat.
"""
await self.send_json(
{
"msg_type": status.MSG_TYPE_ENTER,
"room": event["room"]
}, )
async def notice_leave(self, event):
"""
Called when someone has left our chat.
"""
await self.send_json(
{
"msg_type": status.MSG_TYPE_LEAVE,
"room": event["room"],
}, )
async def notice_message(self, event):
"""
Called when someone has messaged our chat.
"""
await self.send_json(
{
"msg_type": status.MSG_TYPE_MESSAGE,
"room": self.room,
"message": event["message"],
"created": event["created"],
"topic": event["topic"],
}, )
(2)status.py的内容如下所示：
NOTIFY_USERS_ON_ENTER_OR_LEAVE_ROOMS = True
MSG_TYPE_MESSAGE = 0 # For standard messages
MSG_TYPE_WARNING = 1 # For yellow messages
MSG_TYPE_ALERT = 2 # For red & dangerous alerts
MSG_TYPE_MUTED = 3 # For just OK information that doesn't bother users
MSG_TYPE_ENTER = 4 # For just OK information that doesn't bother users
MSG_TYPE_LEAVE = 5 # For just OK information that doesn't bother users
MESSAGE_TYPES_CHOICES = (
(MSG_TYPE_MESSAGE, 'MESSAGE'),
(MSG_TYPE_WARNING, 'WARNING'),
(MSG_TYPE_ALERT, 'ALERT'),
(MSG_TYPE_MUTED, 'MUTED'),
(MSG_TYPE_ENTER, 'ENTER'),
(MSG_TYPE_LEAVE, 'LEAVE'),
)
MESSAGE_TYPES_LIST = [
MSG_TYPE_MESSAGE,
MSG_TYPE_WARNING,
MSG_TYPE_ALERT,
MSG_TYPE_MUTED,
MSG_TYPE_ENTER,
MSG_TYPE_LEAVE,
]
(3)exceptions.py的内容如下所示：
class BaseError(Exception):
""" 自定义异常基类 """
def __init__(self, code):
super().__init__(code)
self.code = code
class ClientError(BaseError):
第五步添加routing.py文件，即websocket接口路由相关
from django.urls import path
from practice.consumers import NoticeConsumer, BroadcastConsumer
websocket_urlpatterns = [
path("stream/notice/", NoticeConsumer.as_asgi()),
path("stream/broadcast/", BroadcastConsumer.as_asgi()),
]
推送消息
import os
import json
import datetime
from asgiref.sync import async_to_sync
from channels.layers import get_channel_layer
from django_redis import get_redis_connection
channel_layer = get_channel_layer()
redis_conn = get_redis_connection("default")
def vulnerability_approved(message):
"""管理员漏洞审核通过信息展示界面推送通知"""
async_to_sync(channel_layer.group_send)(
"broadcast", {
"type": "notice.message",
"message": message,
"created": datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
"topic": "vulnerability_approved"
})
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