Django Celery delay() always pushing to default 'celery' queue

Question

I'm ripping my hair out with this one.

The crux of my issue is that, using the Django CELERY_DEFAULT_QUEUE setting in my settings.py is not forcing my tasks to go to that particular queue that I've set up. It always goes to the default celery queue in my broker.

However, if I specify queue=proj:dev in the shared_task decorator, it goes to the correct queue. It behaves as expected.

My setup is as follows:

• Django code on my localhost (for testing and stuff). Executing task .delay()'s via Django's shell (manage.py shell)
• a remote Redis instance configured as my broker
• 2 celery workers configured on a remote machine setup and waiting for messages from Redis (On Google App Engine - irrelevant perhaps)

NB: For the pieces of code below, I've obscured the project name and used proj as a placeholder.

celery.py

from __future__ import absolute_import, unicode_literals

import os
from celery import Celery, shared_task

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'proj.settings')

app = Celery('proj')

app.config_from_object('django.conf:settings', namespace='CELERY', force=True)

app.autodiscover_tasks()


@shared_task
def add(x, y):
    return x + y

settings.py

...
CELERY_RESULT_BACKEND = 'django-db'
CELERY_BROKER_URL = 'redis://:{}@{}:6379/0'.format(
    os.environ.get('REDIS_PASSWORD'),
    os.environ.get('REDIS_HOST', 'alice-redis-vm'))
CELERY_DEFAULT_QUEUE = os.environ.get('CELERY_DEFAULT_QUEUE', 'proj:dev')

The idea is that, for right now, I'd like to have different queues for the different environments that my code exists in: dev, staging, prod. Thus, on Google App Engine, I define an environment variable that is passed based on the individual App Engine service.

Steps

So, with the above configuration, I fire up the shell using ./manage.py shell and run add.delay(2, 2). I get an AsyncResult back but Redis monitor clearly shows a message was sent to the default celery queue:

1497566026.117419 [0 155.93.144.189:58887] "LPUSH" "celery"
...

What am I missing?

Not to throw a spanner in the works, but I feel like there was a point today at which this was actually working. But for the life of me, I can't think what part of my brain is failing me here.

Stack versions:

• python: 3.5.2
• celery: 4.0.2
• redis: 2.10.5
• django: 1.10.4

Answer 1

This issue is far more simple than I thought - incorrect documentation!!

The Celery documentation asks us to use CELERY_DEFAULT_QUEUE to set the task_default_queue configuration on the celery object.

Ref: http://docs.celeryproject.org/en/latest/userguide/configuration.html#new-lowercase-settings

We should currently use CELERY_TASK_DEFAULT_QUEUE. This is an inconsistency in the naming of all the other settings' names. It was raised on Github here - https://github.com/celery/celery/issues/3772

Solution summary

Using CELERY_DEFAULT_QUEUE in a configuration module (using config_from_object) has no effect on the queue.

Use CELERY_TASK_DEFAULT_QUEUE instead.