This is an example for running Celery applications that demonstrates how to load multiple task modules from different files using environment variables. It also shows how to utilize a get celery config approach that allows for decoupling inclusion of tasks from the initialization of the Celery application. It also includes a derived Celery task called CustomTask for showing how to handle on_success and on_failure task control events. I find this easier to manage my Celery workers and the applications that publish tasks to them.
This is not an official Celery project, it is just examples I use to test my workers and tasks.
I hope you find it valuable.
pip install celery-loaders
This is only needed if redis is not running already on port 6739. It also requires having docker and docker-compose available to your user.
./run-redis.sh
Please run this from the base repository directory or the module paths to the Celery tasks will fail.
./run-celery-loaders-worker.sh
Starting Worker=celery_worker
celery worker -A celery_worker -c 1 -l INFO -n default@%h
2018-02-24 13:01:49,843 - worker - INFO - start - worker
2018-02-24 13:01:49,843 - worker - INFO - broker=redis://localhost:6379/9 backend=redis://localhost:6379/10 include_tasks=['celery_loaders.work_tasks.tasks', 'celery_loaders.work_tasks.always_fails_tasks']
2018-02-24 13:01:49,844 - get_celery_app - INFO - creating celery app=worker tasks=['celery_loaders.work_tasks.tasks', 'celery_loaders.work_tasks.always_fails_tasks']
2018-02-24 13:01:49,845 - worker - INFO - starting celery
-------------- default@dev v4.1.0 (latentcall)
---- **** -----
--- * *** * -- Linux-4.13.0-16-generic-x86_64-with-Ubuntu-17.10-artful 2018-02-24 13:01:49
-- * - **** ---
- ** ---------- [config]
- ** ---------- .> app: worker:0x7f384346e550
- ** ---------- .> transport: redis://localhost:6379/9
- ** ---------- .> results: redis://localhost:6379/10
- *** --- * --- .> concurrency: 1 (prefork)
-- ******* ---- .> task events: OFF (enable -E to monitor tasks in this worker)
--- ***** -----
-------------- [queues]
.> celery exchange=celery(direct) key=celery
[tasks]
. celery_loaders.work_tasks.always_fails_tasks.always_fails
. celery_loaders.work_tasks.tasks.do_some_work
2018-02-24 13:01:49,956 - celery.worker.consumer.connection - INFO - Connected to redis://localhost:6379/9
2018-02-24 13:01:49,963 - celery.worker.consumer.mingle - INFO - mingle: searching for neighbors
2018-02-24 13:01:50,981 - celery.worker.consumer.mingle - INFO - mingle: all alone
2018-02-24 13:01:51,013 - celery.apps.worker - INFO - default@dev ready.
Run this in another terminal with the celery_loaders pip available to the python 3 runtime.
./run-celery-loaders-tests.py 2018-02-24 13:01:56,768 - worker - INFO - start - worker 2018-02-24 13:01:56,768 - worker - INFO - broker=redis://localhost:6379/9 backend=redis://localhost:6379/10 include_tasks=['celery_loaders.work_tasks.tasks', 'celery_loaders.work_tasks.always_fails_tasks'] 2018-02-24 13:01:56,768 - worker - INFO - broker=redis://localhost:6379/9 backend=redis://localhost:6379/10 2018-02-24 13:01:56,769 - get_celery_app - INFO - creating celery app=worker tasks=['celery_loaders.work_tasks.tasks', 'celery_loaders.work_tasks.always_fails_tasks'] 2018-02-24 13:01:56,781 - worker - INFO - calling task - success testing 2018-02-24 13:01:56,822 - worker - INFO - calling task=celery_loaders.work_tasks.tasks.do_some_work - success job_id=3dcd5066-46fe-43cc-b0c6-8cff5499a7b1 2018-02-24 13:01:56,822 - worker - INFO - calling task - failure testing 2018-02-24 13:01:56,823 - worker - INFO - calling task=celery_loaders.work_tasks.always_fails_tasks.always_fails - failure job_id=c6f91e65-f541-40ad-9226-eaf97b223723 2018-02-24 13:01:56,823 - worker - INFO - end - worker
2018-02-24 13:01:56,822 - celery.worker.strategy - INFO - Received task: celery_loaders.work_tasks.tasks.do_some_work[3dcd5066-46fe-43cc-b0c6-8cff5499a7b1]
2018-02-24 13:01:56,824 - tasks - INFO - task - do_some_work - start work_dict={'user_id': 1}
2018-02-24 13:01:56,824 - tasks - INFO - task - do_some_work - done
2018-02-24 13:01:56,828 - custom_task - INFO - custom_task SUCCESS - retval=True task_id=3dcd5066-46fe-43cc-b0c6-8cff5499a7b1 args=[{'user_id': 1}] kwargs={}
2018-02-24 13:01:56,828 - celery.app.trace - INFO - Task celery_loaders.work_tasks.tasks.do_some_work[3dcd5066-46fe-43cc-b0c6-8cff5499a7b1] succeeded in 0.004043873999762582s: True
2018-02-24 13:01:57,007 - celery.worker.strategy - INFO - Received task: celery_loaders.work_tasks.always_fails_tasks.always_fails[c6f91e65-f541-40ad-9226-eaf97b223723]
2018-02-24 13:01:57,009 - always_fails_tasks - INFO - task - always_fails - start work_dict={'test_failure': 'Should fail now 2018-02-24T13:01:56.781481'}
2018-02-24 13:01:57,010 - custom_task - ERROR - custom_task FAIL - exc=Should fail now 2018-02-24T13:01:56.781481 args=[{'test_failure': 'Should fail now 2018-02-24T13:01:56.781481'}] kwargs={}
2018-02-24 13:01:57,010 - celery.app.trace - ERROR - Task celery_loaders.work_tasks.always_fails_tasks.always_fails[c6f91e65-f541-40ad-9226-eaf97b223723] raised unexpected: Exception('Should fail now 2018-02-24T13:01:56.781481',)
Traceback (most recent call last):
File "/home/jay/.venvs/celeryloaders/lib/python3.6/site-packages/celery/app/trace.py", line 374, in trace_task
R = retval = fun(*args, **kwargs)
File "/home/jay/.venvs/celeryloaders/lib/python3.6/site-packages/celery/app/trace.py", line 629, in __protected_call__
return self.run(*args, **kwargs)
File "/opt/redten/stack/jwt/webapp/celery_examples/build/lib/celery_loaders/work_tasks/always_fails_tasks.py", line 32, in always_fails
"simulating a failure"))
Exception: Should fail now 2018-02-24T13:01:56.781481
Start a named Celery Task and pass in data from a file containing a testing JSON payload
./run-celery-task.py -f tests/data/user_lookup_test.json -t celery_loaders.work_tasks.tasks.do_some_work -w 5.0 2018-02-26 00:11:50,192 - run-celery-task - INFO - start - run-celery-task 2018-02-26 00:11:50,192 - run-celery-task - INFO - connecting Celery=run-celery-task broker=redis://localhost:6379/9 backend=redis://localhost:6379/10 tasks=['celery_loaders.work_tasks.tasks'] 2018-02-26 00:11:50,192 - get_celery_app - INFO - creating celery app=run-celery-task tasks=['celery_loaders.work_tasks.tasks'] 2018-02-26 00:11:50,207 - run-celery-task - INFO - app.broker_url=redis://localhost:6379/9 calling task=celery_loaders.work_tasks.tasks.do_some_work data={'user_id': 1} 2018-02-26 00:11:50,264 - run-celery-task - INFO - calling task=celery_loaders.work_tasks.tasks.do_some_work - started job_id=561c80bc-0bab-4387-a842-4372d11c8291 2018-02-26 00:11:50,264 - run-celery-task - INFO - task=561c80bc-0bab-4387-a842-4372d11c8291 - waiting seconds=5.0 for results 2018-02-26 00:11:50,268 - run-celery-task - INFO - task=celery_loaders.work_tasks.tasks.do_some_work - success job_id=561c80bc-0bab-4387-a842-4372d11c8291 task_result={'job_results': 'some response key=c60adfdc-e27c-41f4-8440-666be599ab4a'} 2018-02-26 00:11:50,268 - run-celery-task - INFO - end - run-celery-taskVerify the Worker Processed the Task
2018-02-26 00:11:50,265 - celery.worker.strategy - INFO - Received task: celery_loaders.work_tasks.tasks.do_some_work[561c80bc-0bab-4387-a842-4372d11c8291] 2018-02-26 00:11:50,266 - tasks - INFO - task - do_some_work - start work_dict={'user_id': 1} 2018-02-26 00:11:50,266 - tasks - INFO - task - {'job_results': 'some response key=c60adfdc-e27c-41f4-8440-666be599ab4a'} - result=do_some_work done 2018-02-26 00:11:50,267 - custom_task - INFO - custom_task SUCCESS - retval={'job_results': 'some response key=c60adfdc-e27c-41f4-8440-666be599ab4a'} task_id=561c80bc-0bab-4387-a842-4372d11c8291 args=[{'user_id': 1}] kwargs={} 2018-02-26 00:11:50,268 - celery.app.trace - INFO - Task celery_loaders.work_tasks.tasks.do_some_work[561c80bc-0bab-4387-a842-4372d11c8291] succeeded in 0.001375271000142675s: {'job_results': 'some response key=c60adfdc-e27c-41f4-8440-666be599ab4a'}
virtualenv -p python3 ~/.venvs/celeryloaders && source ~/.venvs/celeryloaders/bin/activate && pip install -e .
Run tests
python setup.py test
flake8 . pycodestyle .
Apache 2.0