如何在 django 中只运行一次 celery 任务？

Question

from __future__ import absolute_import, unicode_literals

from celery import shared_task
from celery.task import periodic_task
from celery.schedules import crontab
from datetime import timedelta



@periodic_task(run_every=(crontab(minute='*/1')), name='greeting_task')
def greeting_task():
    print('hello Dias!')

Can I create a function that runs only once at certain time with crontab? PLEASE, HELP!!! thanks in advance!

Answer 1

If you are using Django-Celery-Beat , it has the ability to create tasks that run only once at a specific date/time using the ClockedSchedule model. It's not in the documentation for some reason but you can easily configure it through the Django Admin.

Answer 2

You need to change the parameters for crontab .

Example: If you want the task to be run once at 5AM everyday:

@periodic_task(run_every=(crontab(minute='0', hour='5')), name='greeting_task')
def greeting_task():
    print('hello Dias!')

crontab(minute='*/1') will run the task at every minute. Read about crontab syntax here: https://en.wikipedia.org/wiki/Cron