A simple example about how to use error callbacks in celery

celery_error_callback_example.py

"""
celery -A celery_error_callback_example.celery worker --loglevel=info
python celery_error_callback_example.py
"""

import time

from celery import Celery

celery = Celery(
    'celery_error_callback_example', broker='amqp://guest@localhost//')


@celery.task
def do_something_important(important_arg):
    print('doing important stuff with arg {}'.format(important_arg))
    if 'error' in important_arg:
        raise ValueError('Oh boi, something went wrong')


@celery.task
def error_callback(request, exception, traceback):
    print('ERROR:')
    print('request: {}'.format(request))
    print('exception: {}'.format(exception))
    print('traceback: {}'.format(traceback))


def main():
    do_something_important.s('good argument').on_error(
        error_callback.s()).delay()
    time.sleep(1)
    do_something_important.s('error argument').on_error(
        error_callback.s()).delay()


if __name__ == "__main__":
    main()