Django：如何忽略 Celery 的任务？

Question

Without changing the code itself, Is there a way to ignore tasks in Celery?

For example, when using Django mails, there is a Dummy Backend setting. This is perfect since it allows me, from a .env file to deactivate mail sending in some environments (like testing, or staging). The code itself that handles mail sending is not changed with if statements or decorators.

For celery tasks, I know I could do it in code using mocks or decorators, but I'd like to do it in a clean way that is 12factors compliant, like with Django mails. Any idea?

EDIT to explain why I want to do this:

One of the main motivation behind this, is that it creates coupling between Django web server and Celery tasks. For example, when running unit tests, if the broker server (Redis for me) is not running, then if delay() method is called, it freezes forever, because there is no timeout when Celery tries to send a task to Redis. From an architecture view, this is very bad. I'd like my unit tests can run properly without the requirement to run a Celery broker!

Thanks!

Answer 1

As far as the coupling is concerned, your Django application would still be tied to celery if you use a dummy backend. Just your tasks won't execute. Maybe this is acceptable in your case but in my opinion, it can cause some problems. For example, if the piece of code you are trying to test, submits a task to celery, and in a later part, tries to retrieve the result for that task, it will fail. Because the dummy backend will never execute the task.

For unit testing, as you mentioned in your question, you can use the task_always_eager setting. If you turn it on, your Django app will no longer depend upon a running worker. It will execute tasks in the same thread in a synchronous fashion and return the result.