Django CronTask

Cron style scheduler for asynchronous tasks in Django.

• setup recurring tasks via crontab syntax
• lightweight helpers build on top of APScheduler
• Sentry cron monitor support

Sponsors

Setup

You need to have Django's Task framework setup properly.

python3 -m pip install django-crontask
# or
python3 -m pip install django-crontask[sentry]  # with sentry cron monitor support

Add crontask to your INSTALLED_APPS in settings.py:

# settings.py
INSTALLED_APPS = [
    "crontask",
    # ...
]

Finally, you launch the scheduler in a separate process:

python3 manage.py crontask

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. This is important if you have multiple instances of your application running.

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

Usage

# tasks.py
import logging

from django.tasks import task
from crontask import cron

logger = logging.getLogger(__name__)


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

Advanced Trigger Usage

You can also use other trigger types from APScheduler. Just import the trigger and use it in the cron decorator.

import logging

from django.tasks import task
from django.utils import timezone
from apscheduler.triggers.interval import IntervalTrigger
from crontask import cron

logger = logging.getLogger(__name__)

every_ten_minutes = IntervalTrigger(
    minutes=10, timezone=timezone.get_default_timezone()
)


@cron(every_ten_minutes)
@task
def my_interval_task():
    logger.info("Hello from interval task")

Sentry Cron Monitors

If you use Sentry suitable tasks will be automatically monitored. The monitor's slug will be the actor's name. Like my_task in the example above.

Certain triggers are not supported by Sentry as well as sub-minute intervals. In these cases, no monitor will be created and no telemetry will be sent.

Pass a custom config via sentry_monitor_config or set it to None to disable Sentry monitoring for a single task:

@cron("* * * * *", sentry_monitor_config=None)
@task
def my_task_without_sentry(): ...

The crontask command

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

Run 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.