使用Celery与django-verify-email发送验证邮件时遇序列化及属性错误

我尝试用django-verify-email包搭配Celery实现异步发送邮件验证的功能，以下是我的代码：

task.py #

from celery import shared_task
from verify_email.email_handler import send_verification_email

@shared_task
def send_user_email(request, form):
    inactive_user = send_verification_email(request, form)

sign_up.py #

from django.shortcuts import render, redirect
from django.contrib import messages
from .tasks import send_user_email

def signup(request, form_class, template_name, success_message, redirect_url):
    if request.user.is_authenticated:
        return redirect(redirect_url)
    form = form_class()

    if request.method == 'POST':
        form = form_class(request.POST)
        if form.is_valid():
            send_user_email.delay(request, form=form)
            messages.success(request, success_message)
            return redirect(redirect_url)
        else:
            messages.error(request, f'Error creating account. Please check the form.')
            return render(request, template_name, {'form': form})

    context = {'form': form}
    return render(request, template_name, context)

任务控制台错误信息 #

[2024-01-03 19:08:34,231: ERROR/ForkPoolWorker-2] Task user.tasks.send_user_email[1f521272-e7e4-4ae0-8fd8-ef1e0ad551e5] raised unexpected: AttributeError("'dict' object has no attribute 'save'")
Traceback (most recent call last):
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/celery/app/trace.py", line 477, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/celery/app/trace.py", line 760, in __protected_call__
    return self.run(*args, **kwargs)
  File "/home/foli/code/django/freeacademy/user/tasks.py", line 7, in send_user_email
    inactive_user = send_verification_email(request, form_data)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/verify_email/email_handler.py", line 94, in send_verification_email
    return _VerifyEmail().send_verification_link(request, form)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/verify_email/email_handler.py", line 32, in send_verification_link
    inactive_user = form.save(commit=False)
AttributeError: 'dict' object has no attribute 'save'

Web控制台错误信息 #

Traceback (most recent call last):
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/serialization.py", line 41, in _reraise_errors
    yield
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/serialization.py", line 220, in dumps
    payload = encoder(data)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/utils/json.py", line 57, in dumps
    return _dumps(s, cls=cls, **dict(default_kwargs, **kwargs))
  File "/usr/lib/python3.10/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "/usr/lib/python3.10/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.10/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/utils/json.py", line 45, in default
    return super().default(o)
  File "/usr/lib/python3.10/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '

During handling of the above exception (Object of type WSGIRequest is not JSON serializable), another exception occurred:
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/foli/code/django/freeacademy/user/views.py", line 128, in teacher_signup
    return signup(
  File "/home/foli/code/django/freeacademy/user/user_signup.py", line 17, in signup
    send_user_email.delay(request, form)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/celery/app/task.py", line 444, in delay
    return self.apply_async(args, kwargs)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/celery/app/task.py", line 594, in apply_async
    return app.send_task(
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/celery/app/base.py", line 799, in send_task
    amqp.send_task_message(P, name, message, **options)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/celery/app/amqp.py", line 518, in send_task_message
    ret = producer.publish(
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/messaging.py", line 175, in publish
    body, content_type, content_encoding = self._prepare(
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/messaging.py", line 268, in _prepare
    body) = dumps(body, serializer=serializer)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/serialization.py", line 219, in dumps
    with _reraise_errors(EncodeError):
  File "/usr/lib/python3.10/contextlib.py", line 153, in __exit__
    self.gen.throw(typ, value, traceback)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/serialization.py", line 45, in _reraise_errors
    reraise(wrapper, wrapper(exc), sys.exc_info()[2])
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/exceptions.py", line 34, in reraise
    raise value.with_traceback(tb)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/serialization.py", line 41, in _reraise_errors
    yield
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/serialization.py", line 220, in dumps
    payload = encoder(data)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/utils/json.py", line 57, in dumps
    return _dumps(s, cls=cls, **dict(default_kwargs, **kwargs))
  File "/usr/lib/python3.10/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "/usr/lib/python3.10/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.10/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/home/foli/code/django/freeacademy/.freemindedAcademy/lib/python3.10/site-packages/kombu/utils/json.py", line 45, in default
    return super().default(o)
  File "/usr/lib/python3.10/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '

Exception Type: EncodeError at /users/teacher_signup/
Exception Value: Object of type WSGIRequest is not JSON serializable

我猜测问题出在包中的inactive_user变量，但试了多种配置都没解决。

错误原因 #

1. WSGIRequest无法序列化：Celery默认用JSON序列化任务参数，Django的WSGIRequest对象不支持JSON序列化，触发Web控制台的编码错误。
2. 表单对象序列化丢失方法：表单对象被序列化后会变成普通字典，不再具备save()方法，导致任务执行时抛出属性错误。

修复方案 #

方案一：修改视图与任务，传递用户ID和请求上下文 #

更新sign_up.py

from django.shortcuts import render, redirect
from django.contrib import messages
from .tasks import send_user_email

def signup(request, form_class, template_name, success_message, redirect_url):
    if request.user.is_authenticated:
        return redirect(redirect_url)
    form = form_class()

    if request.method == 'POST':
        form = form_class(request.POST)
        if form.is_valid():
            # 先创建未激活用户并保存到数据库
            inactive_user = form.save(commit=False)
            inactive_user.is_active = False
            inactive_user.save()
            # 传递用户ID、协议和域名给任务
            send_user_email.delay(
                user_id=inactive_user.id,
                scheme=request.scheme,
                host=request.get_host()
            )
            messages.success(request, success_message)
            return redirect(redirect_url)
        else:
            messages.error(request, 'Error creating account. Please check the form.')
            return render(request, template_name, {'form': form})

    context = {'form': form}
    return render(request, template_name, context)

更新task.py

from celery import shared_task
from django.contrib.auth import get_user_model
from django.http import HttpRequest
from verify_email.email_handler import send_verification_email
# 替换成你的注册表单类
from .forms import SignUpForm

User = get_user_model()

@shared_task
def send_user_email(user_id, scheme, host):
    user = User.objects.get(id=user_id)
    # 构建模拟request对象，满足django-verify-email的要求
    mock_request = HttpRequest()
    mock_request.scheme = scheme
    mock_request.META['HTTP_HOST'] = host
    
    # 用用户实例初始化表单
    form = SignUpForm(instance=user)
    send_verification_email(mock_request, form)

方案二：手动生成验证链接发送邮件（不依赖表单） #

如果不想依赖django-verify-email的表单处理逻辑，可以手动实现邮件发送：

from celery import shared_task
from django.contrib.auth import get_user_model
from django.core.mail import send_mail
from django.contrib.auth.tokens import default_token_generator
from django.urls import reverse

User = get_user_model()

@shared_task
def send_user_email(user_id, scheme, host):
    user = User.objects.get(id=user_id)
    # 生成验证token
    token = default_token_generator.make_token(user)
    # 构建验证URL
    verify_path = reverse('verify_email', kwargs={'uidb64': user.pk, 'token': token})
    full_verify_url = f"{scheme}://{host}{verify_path}"
    
    # 发送验证邮件
    subject = '邮箱验证通知'
    message = f"请点击以下链接完成邮箱验证：\n{full_verify_url}"
    send_mail(subject, message, 'your-email@example.com', [user.email])

内容的提问来源于stack exchange，提问作者foliwe83