Data

Tools

Indexes

Applications

Experiments

Awesome

An open API service indexing awesome lists of open source software.

https://github.com/jay-johnson/celery-loaders

Examples for Celery applications and task loading
https://github.com/jay-johnson/celery-loaders

celery distributed-computing docker python redis

Last synced: 3 months ago
JSON representation

Examples for Celery applications and task loading

Awesome Lists containing this project

README 

          
Examples for Celery Applications and Task Loading

=================================================



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.



Install

-------



::



    pip install celery-loaders



Start Redis

-----------



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



Start Celery Worker

-------------------



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 Success and Failure Tests

-----------------------------



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



Confirm the Celery Worker Processed the Tasks

---------------------------------------------



::



    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



Debug a Celery Task from the Command Line

-----------------------------------------



#.  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-task



#.  Verify 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'}



Development

-----------



::



    virtualenv -p python3 ~/.venvs/celeryloaders && source ~/.venvs/celeryloaders/bin/activate && pip install -e .

    

Run tests



::



    python setup.py test    



Linting

-------



::



    flake8 .

    pycodestyle .



License

=======



Apache 2.0