kombu.exceptions.EncodeError：<flask'src'=“”>不是JSON可序列化的

Question

我正在尝试使用Celery和RabbitMQ异步发送电子邮件。这是我第一次使用Celery，所以我不太熟悉一些错误。我意识到回溯来自一个名为kombu的包，我知道它是Celery的依赖。我只是无法调试它。

每当我测试发送电子邮件时都会发生回溯。

回溯：

[2017-05-14 12:35:08,093] ERROR in app: Exception on /home [POST]
Traceback (most recent call last):
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/serialization.py", line 50, in _reraise_errors
    yield
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/serialization.py", line 221, in dumps
    payload = encoder(data)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/utils/json.py", line 72, in dumps
    **dict(default_kwargs, **kwargs))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/__init__.py", line 237, in dumps
    **kw).encode(obj)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/encoder.py", line 198, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/encoder.py", line 256, in iterencode
    return _iterencode(o, 0)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/utils/json.py", line 62, in default
    return super(JSONEncoder, self).default(o)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/encoder.py", line 179, in default
    raise TypeError(repr(o) + " is not JSON serializable")
TypeError: <Flask 'src'> is not JSON serializable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/flask/_compat.py", line 33, in reraise
    raise value
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/flask/app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/flask/app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/kai/github-projects/Ticket-System/src/views.py", line 139, in home
    email_notification(cust_f_name, cust_email, tix_num)
  File "/Users/kai/github-projects/Ticket-System/src/notifications.py", line 71, in email_notification
    c_name=cust_name, tix=tix))
  File "/Users/kai/github-projects/Ticket-System/src/notifications.py", line 54, in send_email
    send_async_email.delay(app, msg)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/celery/app/task.py", line 412, in delay
    return self.apply_async(args, kwargs)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/celery/app/task.py", line 535, in apply_async
    **options
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/celery/app/base.py", line 737, in send_task
    amqp.send_task_message(P, name, message, **options)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/celery/app/amqp.py", line 558, in send_task_message
    **properties
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/messaging.py", line 169, in publish
    compression, headers)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/messaging.py", line 252, in _prepare
    body) = dumps(body, serializer=serializer)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/serialization.py", line 221, in dumps
    payload = encoder(data)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/contextlib.py", line 77, in __exit__
    self.gen.throw(type, value, traceback)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/serialization.py", line 54, in _reraise_errors
    reraise(wrapper, wrapper(exc), sys.exc_info()[2])
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/vine/five.py", line 175, in reraise
    raise value.with_traceback(tb)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/serialization.py", line 50, in _reraise_errors
    yield
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/serialization.py", line 221, in dumps
    payload = encoder(data)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/utils/json.py", line 72, in dumps
    **dict(default_kwargs, **kwargs))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/__init__.py", line 237, in dumps
    **kw).encode(obj)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/encoder.py", line 198, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/encoder.py", line 256, in iterencode
    return _iterencode(o, 0)
  File "/Users/kai/github-projects/Ticket-System/venv/lib/python3.5/site-packages/kombu/utils/json.py", line 62, in default
    return super(JSONEncoder, self).default(o)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/json/encoder.py", line 179, in default
    raise TypeError(repr(o) + " is not JSON serializable")
kombu.exceptions.EncodeError: <Flask 'src'> is not JSON serializable

发送电子邮件的代码位于我的notifications.py

内

notifications.py

import json

from flask import render_template
from flask_mail import Message

from src import app
from src.config import mail

from celery import Celery

with open('src/config_values.json') as f:
    config_f = json.load(f)

celery = Celery('tasks', broker='amqp://localhost//')

@celery.task()
def send_async_email(app, msg):

    with app.app_context():
        mail.send(msg)


def send_email(subject, sender, recipients, html_body):

    msg = Message(subject, sender=sender, recipients=recipients)
    msg.html = html_body
    send_async_email.delay(app, msg)


def email_notification(cust_name, cust_email, tix):

    send_email("[Support Ticket #{tix}]!".format(tix=tix),
               config_f['MAIL_USERNAME'],
               [cust_email],
               render_template("ticket_email.html",
                               c_name=cust_name, tix=tix))

要初始化电子邮件，我使用email_notification文件中的views.py功能

views.py

from src.notifications import email_notification

@app.route('/')
def home():
    form = TicketForm()

    if form.validate_on_submit() and request.method == 'POST':

        # Handle form here ....

        email_notification(cust_f_name, cust_email, tix_num)

修改

这是我的config.py文件，其中包含app个__init__.py个app文件，我{创建'import json import os import sys from flask_admin import Admin from flask_bootstrap import Bootstrap from flask_mail import Mail from flask_socketio import SocketIO from flask_sqlalchemy import SQLAlchemy from src import app # JSON config file with open('src/config_values.json') as f: config_f = json.load(f) def db_uri(system): """ Check system type for database URI setup :param system: `sys.platform()` will be passed in :return: system type """ # Mac if system == 'darwin': uri = 'sqlite:////' + os.getcwd() + '/ticket_system.sqlite' # Windows elif system == 'win32': uri = r'sqlite:///' + os.getcwd() + '\ticket_system.sqlite' # Linux elif system == 'linux': uri = 'sqlite:////' + os.getcwd() + '/ticket_system.sqlite' # Linux2 elif system == 'linux2': uri = 'sqlite:////' + os.getcwd() + '/ticket_system.sqlite' # If system could not be determined else: raise FileNotFoundError('SQLite File was not able to be found') # Return system type return uri # All configuration needed for Flask app.secret_key = os.urandom(24) app.config['SQLALCHEMY_DATABASE_URI'] = db_uri(sys.platform) app.config['DATABASE_FILE'] = config_f['DATABASE_FILE'] app.config['SQLALCHEMY_ECHO'] = config_f['SQLALCHEMY_ECHO'] app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = config_f['SQLALCHEMY_TRACK_MODIFICATIONS'] app.config['MAIL_SERVER'] = config_f['MAIL_SERVER'] app.config['MAIL_PORT'] = config_f['MAIL_PORT'] app.config['MAIL_USERNAME'] = config_f['MAIL_USERNAME'] app.config['MAIL_PASSWORD'] = config_f['MAIL_PASSWORD'] app.config['MAIL_USE_TLS'] = config_f['MAIL_USE_TLS'] app.config['MAIL_USE_SSL'] = config_f['MAIL_USE_SSL'] app.config['RECAPTCHA_PUBLIC_KEY'] = config_f['cap_pub'] app.config['RECAPTCHA_PRIVATE_KEY'] = config_f['cap_sec'] Bootstrap(app) db = SQLAlchemy(app) mail = Mail(app) admin = Admin(app, name='Tickets', template_mode='bootstrap3') socketio = SocketIO(app) ：

config.py

from flask import Flask

app = Flask(__name__)
from src.views import app

__初始化__。PY

Ticket-System\
    src\
        __init__.py
        config.json
        config_values.json
        decorators.py
        forms.py
        models.py
        notifications.py
        views.py
    venv\
    api_check.py
    requirements.txt
    run.py

这是我的整个文件夹结构

def index
  @posts = current_author.posts.most_recent
end

def show
end

def new
  @post = current_author.posts.new
end

private
  def set_post
    @post = current_author.posts.friendly.find(params[:id])
  end

  def post_params
    params.require(:post).permit(:title, :body, :description, :banner_image_url, :tag_list)
  end
end

end

Answer 1

当您与Celery异步执行任务时，您会向代理发送消息。因此，在引擎盖下有一个消息的序列化，这意味着您传递给任务的参数也被序列化。由于Celery v4.0默认序列化程序是JSON。

在您的任务send_async_email中，您传递了一个参数app，这可能不是JSON可序列化的，这就是您出错的原因。

在我看来，如果可以，最好避免将对象实例传递给任务。所以在你的情况下，这就是我要做的事情：

notifications.py

@celery.task()
def email_notification(cust_name, cust_email, tix):
    subject = "[Support Ticket #{tix}]!".format(tix=tix)
    sender = config_f['MAIL_USERNAME']
    recipients = [cust_email]
    html_body =  render_template("ticket_email.html", c_name=cust_name, tix=tix)

    msg = Message(subject, sender=sender, recipients=recipients)
    msg.html = html_body
    with app.app_context():
        mail.send(msg)

<强> views.py

from src.notifications import email_notification
@app.route('/')
def home():
    form = TicketForm()

    if form.validate_on_submit() and request.method == 'POST':

        # Handle form here ....

        email_notification.delay(cust_f_name, cust_email, tix_num)