我想创建一个后台任务来更新特定日期的记录。我将Django和Celery与RabbitMQ结合使用。
使用此虚拟任务函数保存模型时,我设法使任务被调用:
tasks.py
from __future__ import absolute_import
from celery import Celery
from celery.utils.log import get_task_logger
logger = get_task_logger(__name__)
app = Celery('tasks', broker='amqp://localhost//')
@app.task(name='news.tasks.update_news_status')
def update_news_status(news_id):
# (I pass the news id and return it, nothing complicated about it)
return news_id
此任务是通过 models.py
中的save()方法调用的from django.db import models
from celery import current_app
class News(models.model):
(...)
def save(self, *args, **kwargs):
current_app.send_task('news.tasks.update_news_status', args=(self.id,))
super(News, self).save(*args, **kwargs)
事情是我想将我的新闻模型导入tasks.py ,但是如果我想这样:
from .models import News
我收到此错误:
django.core.exceptions.ImproperlyConfigured:请求的设置 DEFAULT_INDEX_TABLESPACE,但未配置设置。你必须 定义环境变量DJANGO_SETTINGS_MODULE或调用 settings.configure(),然后再访问设置。
mi celery.py 的外观如下
from __future__ import absolute_import, unicode_literals
from celery import Celery
import os
# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'myapp.settings')
app = Celery('myapp')
# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
# should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')
# Load task modules from all registered Django app configs.
app.autodiscover_tasks()
@app.task(bind=True)
def debug_task(self):
print('Request: {0!r}'.format(self.request))
我已经尝试过:
并遇到了不同的错误,但是最后,我无法在task.py
中导入任何模块。我的配置可能有问题,但是我看不到错误,我按照The Celery Docs: First steps with Django
中的步骤进行操作此外,我的项目结构如下:
├── myapp
│ ├── __init__.py
├── ├── celery.py
│ ├── settings.py
│ ├── urls.py
│ └── wsgi.py
├── news
│ ├── __init__.py
│ ├── admin.py
│ ├── apps.py
│ ├── tasks.py
│ ├── urls.py
│ ├── models.py
│ ├── views.py
├── manage.py
我正在像这样从myapp
目录执行工作程序:
celery -A news.tasks worker --loglevel=info
我在这里想念什么?预先感谢您的帮助!
lambda:settings.INSTALLED_APPS
编辑
进行注释中建议的更改后:
将此添加到celery.py
app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)
并导入内部方法:tasks.py
from __future__ import absolute_import
from celery import Celery
from celery.utils.log import get_task_logger
logger = get_task_logger(__name__)
app = Celery('tasks', broker='amqp://localhost//')
@app.task(name='news.tasks.update_news_status')
def update_news_status(news_id):
from .models import News
return news_id
我收到以下错误:
[2018-07-20 12:24:29,337: ERROR/ForkPoolWorker-1] Task news.tasks.update_news_status[87f9ec92-c260-4ee9-a3bc-5f684c819f79] raised unexpected: ValueError('Attempted relative import in non-package',)
Traceback (most recent call last):
File "/Users/carla/Develop/App/backend/myapp-venv/lib/python2.7/site-packages/celery/app/trace.py", line 382, in trace_task
R = retval = fun(*args, **kwargs)
File "/Users/carla/Develop/App/backend/myapp-venv/lib/python2.7/site-packages/celery/app/trace.py", line 641, in __protected_call__
return self.run(*args, **kwargs)
File "/Users/carla/Develop/App/backend/news/tasks.py", line 12, in update_news_status
from .models import News
ValueError: Attempted relative import in non-package
答案 0 :(得分:2)
好吧,所以对于任何为此苦苦挣扎的人来说……原来我的celery.py并不是从设置中读取环境变量。
经过一周的研究,我意识到 Celery不是Django的进程,而是在Django之外运行的进程(duh),所以当我尝试加载设置时,它们被加载了,但是那么我将无法访问在.env中定义的env变量(我使用dotenv库)。 Celery试图在我的.bash_profile中查找env变量(当然)
最后,我的解决方案是在定义了celery.py
的同一目录中创建一个帮助器模块,并使用以下
load_env.py
from os.path import dirname, join
import dotenv
def load_env():
"Get the path to the .env file and load it."
project_dir = dirname(dirname(__file__))
dotenv.read_dotenv(join(project_dir, '.env'))
然后在我的 celery.py 上(注意最后的导入和第一条说明)
from __future__ import absolute_import, unicode_literals
from celery import Celery
from django.conf import settings
import os
from .load_env import load_env
load_env()
# set the default Django settings module for the 'celery' program.
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myapp.settings")
app = Celery('myapp')
# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
# should have a `CELERY_` prefix.
app.config_from_object('myapp.settings', namespace='CELERY')
# Load task modules from all registered Django app configs.
app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)
在加载对load_env()
环境变量的调用之后,芹菜工作者可以访问它们。这样,我现在可以从我的task.py 中访问其他模块,这是我的主要问题。
贷记this guys (Caktus Consulting Group)及其django-project-template,因为如果不是他们的话,我将找不到答案。谢谢。
答案 1 :(得分:0)
尝试类似这样的方法。它在3.1芹菜中工作,导入应在save方法内并在super()之后进行
from django.db import models
class News(models.model):
(...)
def save(self, *args, **kwargs):
(...)
super(News, self).save(*args, **kwargs)
from task import update_news_status
update_news_status.apply_async((self.id,)) #apply_async or delay
答案 2 :(得分:0)
这是我要执行的操作(Django 1.11和celery 4.2),您的celery配置中有问题,您尝试重新声明Celery实例:
tasks.py
from myapp.celery import app # would contain what you need :)
from celery.utils.log import get_task_logger
logger = get_task_logger(__name__)
@app.task(name='news.tasks.update_news_status')
def update_news_status(news_id):
# (I pass the news id and return it, nothing complicated about it)
return news_id
celery.py
from __future__ import absolute_import, unicode_literals
from celery import Celery
from django.conf import settings
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myapp.settings")
app = Celery('myapp', backend='rpc://', broker=BROKER_URL) # your config here
app.config_from_object('django.myapp:settings', namespace='CELERY') # change here
app.autodiscover_tasks()
models.py
from django.db import models
class News(models.model):
(...)
def save(self, *args, **kwargs):
super(News, self).save(*args, **kwargs)
from news.tasks import update_news_status
update_news_status.delay(self.id) # change here
并使用celery -A myapp worker --loglevel=info
启动它,因为您的应用程序是在myapp.celery中定义的,因此-A参数必须是声明conf的应用程序