Demos#

This modules contains 3 mini-applications that showcase using procrastinate in difference contexts:

  • demo_django: a Django application,

  • demo_async: an async application, it could be a FastAPI application, but to make things simpler, it’s just a plain asyncio application.

  • demo_sync: a synchronous application, similarily, it could be representative of a Flask application.

The demos are there both to showcase the code and as a way to easily recreate the issues that are reported in the issues. They are not production-ready code, and if you want to run them, you’ll need to set up the Procrastinate development environment (see contributing doc)

To run the demos, set PROCRASTINATE_APP to procrastinate_demos.<demo_name>.app.app, then run the procrastinate CLI or python -m procrastinate_demos.<demo_name> for the application main entrypoint.

For all apps, you’ll need to have a PostgreSQL database running, and set the PG[...] environment variables. This is taken care of by the . ./dev-env script if you want to use it.

You’ll need 2 terminals to run the demos, one for the procrastinate worker and one for the application. (If you prefer, you can use baclground processes).

Async demo#

Launch the worker in the first terminal:

$ PROCRASTINATE_APP=procrastinate_demos.demo_async.app.app procrastinate worker

In the second terminal, run the application:

$ python -m procrastinate_demos.demo_async

Defer a job by sending commands, as indicated by the application.

Sync demo#

Same with sync:

$ PROCRASTINATE_APP=procrastinate_demos.demo_sync.app.app procrastinate worker

$ python -m procrastinate_demos.demo_sync

Django demo#

In the first terminal, run the migrations, and then the Django server:

$ procrastinate_demos/demo_django/manage.py migrate
$ procrastinate_demos/demo_django/manage.py runserver

In the second terminal, run the procrastinate worker:

$ procrastinate_demos/demo_django/manage.py procrastinate worker

In your browser (http://localhost:8000/), you can now: - Create a book - List books

When a book is created, it’s not “indexed” right away (there’s no real indexing under the hood, it’s just for show). A first job is deferred to index the book, which waits for 5 seconds and defers a second job. The second job updates the book’s status to “indexed”. Reloading the list page should show the book as indexed after about 5 seconds. (The only reason why it’s done in 2 jobs rather than one is to showcase deferring a job from another job.)

You can visit the admin, too. You’ll need to create a superuser first:

$ procrastinate_demos/demo_django/manage.py createsuperuser

Then lauch the server, head to http://localhost:8000/admin/ and see the jobs, the events and the periodic defers.

(…Yes I’m not a frontend dev :) )