custom backend

以redis为例, 本质是用自定义的backend替换RedisBackend.
https://docs.celeryq.dev/en/stable/getting-started/backends-and-brokers/redis.html
celery的组件耦合低, 替换简单, 但是需要注意入参值

code

1. 保存下面代码到 test.py
2. 替换redis url 参数
3. 运行 python test.py

import arrow
from celery import Celery
from celery.backends.redis import RedisBackend
from celery.schedules import crontab

broker_url = 'redis://:123@139.196.213.1:6379/1'
backend_url = 'redis://:123@139.196.1.108:6379/2'


class CustomRedisBackend(RedisBackend):
    task_keyprefix = 'cronjob'

    def __init__(self, app=None, **kwargs):
        kwargs['host'] = kwargs.get("url") or backend_url
        kwargs['app'] = app
        super().__init__(**kwargs)

    def get_key_for_task(self, task_id, key=''):
        """
        overwrite cache key
        """
        key_t = self.key_t
        return key_t('_').join([
            self.task_keyprefix, key_t(task_id)[:9], key_t(key),
        ])


_app = Celery(
    'hello',
    broker='redis://:Pass123456@139.196.213.108:6379/1',
)

_app.conf.update(
    result_backend='test2.CustomRedisBackend',
)


@_app.task
def my_cronjob(arg1):
    # Code for your periodic task goes here
    print("Executing periodic task")
    return f"my_periodic_task: {str(arrow.now())}, arg {str(arg1)}"


@_app.on_after_configure.connect
def setup_periodic_tasks(sender, **kwargs):
    sender.add_periodic_task(crontab(minute='*'), my_cronjob.s(1))


if __name__ == '__main__':
    # celery -A app beat --loglevel=info
    _app.worker_main(['worker', '-B'])