Django 通道自定义身份验证中间件 __call__() 缺少 2 个必需的位置参数：'receive' 和 'send'

Question

我正在为 django 通道编写自定义身份验证中间件

class TokenAuthMiddleware:
    def __init__(self, inner):
        # Store the ASGI application we were passed
        self.inner = inner

    def __call__(self, scope):

        return TokenAuthMiddlewareInstance(scope, self)


class TokenAuthMiddlewareInstance:

    def __init__(self, scope, middleware):
        self.middleware = middleware
        self.scope = dict(scope)
        self.inner = self.middleware.inner

    async def __call__(self, receive, send):
        ## my logic to get validate user and store the user in user data
        ...
        ...
        ...
        self.scope['user'] = user_data
        inner = self.inner(self.scope)
        return await inner(receive, send)

但是在尝试从前端连接到 Web 套接字时出现以下错误

TypeError: __call__() missing 2 required positional arguments: 'receive' and 'send'

Answer 1

我使用 Django Channels 3 设法让它以这种方式工作：

from django.contrib.auth.models import AnonymousUser

from rest_framework.authtoken.models import Token

from channels.auth import AuthMiddlewareStack
from channels.db import database_sync_to_async

import urllib.parse

@database_sync_to_async
def get_user(token):
    try:
        token = Token.objects.get(key=token)
        return token.user
    except Token.DoesNotExist:
        return AnonymousUser()

class TokenAuthMiddleware:
    def __init__(self, inner):
        self.inner = inner
    def __call__(self, scope):
        return TokenAuthMiddlewareInstance(scope, self)


class TokenAuthMiddlewareInstance:
    """
    Yeah, this is black magic:
    https://github.com/django/channels/issues/1399
    """
    def __init__(self, scope, middleware):
        self.middleware = middleware
        self.scope = dict(scope)
        self.inner = self.middleware.inner

    async def __call__(self, receive, send):
        decoded_qs = urllib.parse.parse_qs(self.scope["query_string"])
        if b'token' in decoded_qs:
          token = decoded_qs.get(b'token').pop().decode()
          self.scope['user'] = await get_user(token)
        return await self.inner(self.scope, receive, send)


TokenAuthMiddlewareStack = lambda inner: TokenAuthMiddleware(AuthMiddlewareStack(inner))

Answer 2

供您参考：https://channels.readthedocs.io/en/stable/releases/3.0.0.html

变化自 routing.py

websocket_urlpatterns = [
    re_path(r'ws/chat/(?P<room_name>\w+)/$', consumers.ChatConsumer),
]

至 消费者现在有一个 as_asgi() class 方法，您需要在设置路由时调用该方法：

websocket_urlpatterns = [
    re_path(r'ws/chat/(?P<room_name>\w+)/$', consumers.ChatConsumer.as_asgi()),
]

然后 如果您需要自定义身份验证 https://channels.readthedocs.io/en/stable/topics/authentication.html#custom-authentication

from channels.auth import AuthMiddlewareStack
from channels.db import database_sync_to_async
from django.contrib.auth import get_user_model

User = get_user_model()

@database_sync_to_async
def get_user(user_id):
    try:
        return User.objects.get(id=user_id)
    except User.DoesNotExist:
        return AnonymousUser()
        
class QueryAuthMiddleware:
    """
    Custom middleware (insecure) that takes user IDs from the query string.
    """
        
    def __init__(self, app):
        # Store the ASGI application we were passed
        self.app = app
        
    async def __call__(self, scope, receive, send):
        # Look up user from query string (you should also do things like
        # checking if it is a valid user ID, or if scope["user"] is already
        # populated).
        scope['user'] = await get_user(int(scope["query_string"]))
        
        return await self.app(scope, receive, send)
TokenAuthMiddlewareStack = lambda inner: QueryAuthMiddleware(AuthMiddlewareStack(inner))   

use requirements.txt as following list, and also download package in this order

Django==3.0.8
djangorestframework==3.11.0
websocket-client==0.57.0
redis==3.5.3
asgiref==3.2.10
channels-redis==2.4.2
channels==3.0.1

Answer 3

正如 Yuva Raja 所说，在 Django Channels version 3 中，您需要将路径设置为：

websocket_urlpatterns = [
    re_path(r'ws/chat/(?P<room_name>\w+)/$', consumers.ChatConsumer.as_asgi()),
]

还有一件事，他们在 Custom authentication official documentation 中忘记使用 scope 而不是 self.scope。 所以一定要使用：

scope['user'] = await get_user(int(scope["query_string"]))

而不是他们的例子：

scope['user'] = await get_user(int(self.scope["query_string"]))

Answer 4

from urllib.parse import parse_qs

from django.contrib.auth import get_user_model
from django.contrib.auth.models import AnonymousUser
from django.db import close_old_connections

from channels.auth import AuthMiddlewareStack
from rest_framework_simplejwt.tokens import AccessToken

from channels.db import database_sync_to_async

User = get_user_model()


@database_sync_to_async
def get_user(user_id):
    try:
        return User.objects.get(id=user_id)
    except User.DoesNotExist:
        return AnonymousUser()


class TokenAuthMiddleware:
    def __init__(self, inner):
        self.inner = inner

    async def __call__(self, scope, receive, send):
        close_old_connections()
        query_string = parse_qs(scope['query_string'].decode())
        token = query_string.get('token')

        if not token:
            scope['user'] = AnonymousUser()
            return await self.inner(scope, receive, send)

        access_token = AccessToken(token[0])
        user = await get_user(access_token['id'])

        if isinstance(user, AnonymousUser):
            scope['user'] = AnonymousUser()
            return await self.inner(scope, receive, send)

        if not user.is_active:
            scope['user'] = AnonymousUser()
            return await self.inner(scope, receive, send)

        scope['user'] = user
        return await self.inner(scope, receive, send)


TokenAuthMiddlewareStack = lambda inner: TokenAuthMiddleware(AuthMiddlewareStack(inner))

Answer 5

这个错误发生在我安装的时候channels==2.4.0

将频道更新到 channels==3.0.3（目前最新）解决了这个问题！