Add chapter08 files

[Mitchina]

No description provided.

[marksweb]

It may be worth considering setting CELERY_ALWAYS_EAGER so that anybody not familiar with celery and who hasn't ready to the end (rabbitmq section) of the chapter will be able to submit an order without error.

[Mitchina]

It may be worth considering setting CELERY_ALWAYS_EAGER so that anybody not familiar with celery and who hasn't ready to the end (rabbitmq section) of the chapter will be able to submit an order without error.

@marksweb hi, I'm happy to make that change. My only hesitation is that readers following along with the repository code with CELERY_ALWAYS_EAGER enabled won't see any Processed or Succeeded tasks in Flower later in the chapter, because the tasks will run immediately instead of being queued. Would that be okay?

[marksweb]

@Mitchina yeah I understand that. But the scenario I can see happening is that the reader starts the chapter, downloads the chapter files and they run the server.

Now they've got an app that'll send tasks to the queue but no worker running to process the tasks. Knowledge of that comes late in the chapter when you run a worker and go through the monitoring section.

So if the code was setup to anticipate this with eager tasks and the chapter detailed this at the start. That might be better

[Mitchina]

@marksweb Ok, sure. We can also add a note before Figure 8.25 reminding the reader to check the settings and comment out that line if they want to see the tasks appear in Flower.

Regarding that setting, I noticed in the “What’s new in Celery 4.0” documentation that CELERY_ALWAYS_EAGER was renamed to task_always_eager. With our Django Celery configuration, the setting becomes CELERY_TASK_ALWAYS_EAGER, so I’ll update that in the book as well once it comes back from review.