Dramatiq Crontab

Cron style scheduler for asynchronous Dramatiq tasks in Django.

• setup recurring tasks via crontab syntax
• lightweight helpers build on robust tools like Dramatiq and APScheduler
• Sentry cron monitor support

Setup

You need to have Dramatiq installed and setup properly.

python3 -m pip install dramatiq-crontab
# or
python3 -m pip install dramatiq-crontab[sentry]  # with sentry cron monitor support

Add dramatiq_crontab to your INSTALLED_APPS in settings.py:

# settings.py
INSTALLED_APPS = [
    'dramatiq_crontab',
    # ...
]

Finally, you lauch the scheduler in a separate process:

python3 manage.py crontab

Setup Redis as a lock backend (optional)

If you use Redis as a broker, you can use Redis as a lock backend as well. The lock backend is used to prevent multiple instances of the scheduler from running at the same time.

# settings.py
DRAMATIQ_CRONTAB = {
    "REDIS_URL": "redis://localhost:6379/0",
}

Usage

# tasks.py
import dramatiq
from dramatiq_crontab import cron


@cron("*/5 * * * *")  # every 5 minutes
@dramatiq.actor
def my_task():
    my_task.logger.info("Hello World")

Sentry Cron Monitors

If you use Sentry you can add cron monitors to your tasks. The monitor's slug will be the actor's name. Like my_task in the example above.

The crontab command

$ python3 manage.py crontab --help
usage: manage.py crontab [-h] [--no-task-loading] [--no-heartbeat] [--version] [-v {0,1,2,3}]
                         [--settings SETTINGS] [--pythonpath PYTHONPATH] [--traceback] [--no-color]
                         [--force-color] [--skip-checks]

Run dramatiq task scheduler for all tasks with the `cron` decorator.

options:
  -h, --help            show this help message and exit
  --no-task-loading     Don't load tasks from installed apps.
  --no-heartbeat        Don't start the heartbeat actor.