django-serverless-cron 🦡

django-serverless-cron is a Django app with a simpler approach running cron jobs. This is done through exposing a HTTP endpoint to invoke the jobs that allows you to run any task without having to manage always-on infrastructure.

There is also an option to run jobs via management commands and the Django admin.

Why?

This is essentially a replacement/supplement for a traditional OS \'cron\' or \'job scheduler\' system:

Serverless cron jobs no-longer a pain. Note that if you have alternatives like django-crontab or celery working well for you, good for you! You probably don\'t need this. However, it\'s okay to be curious.
Schedule jobs to run at a frequency that is less than 1 min. (crontab is limited to 1 min)
The machine running crontab is no longer a single point of failure.
The problem with the above systems is that they are often configured at the operating system level, which means their configuration is probably not easily \'portable\' and \'debug-able\' (if you are developing on Windows, the scheduler works differently from Linux or Unix). Also can not easily be integrated into a development environment.
Manually triggered cron jobs. Eg: via the Django Admin.
Alternative to cron services that aren\'t always available on free (and sometimes paid) web hosting services.
Easier access to cron job execution logs and monitoring execution failures.
No need to learn crontab. Think of it as a friendlier alternative to traditional cron jobs. Simple cron job creation. No need for cron syntax, no guessing on job frequency. Easy controls.
Designed around services like [Google Cloud Scheduler]{.title-ref} and [Amazon EventBridge]{.title-ref}.

Documentation

Documentation is graciously hosted at https://django-serverless-cron.readthedocs.io.

Contributions

Feel free to make pull requests and submit issues/requests. Find more detailed instructions under the [contributing]{.title-ref} section.

Alternatively, you can leave a star on the repo to show your support. 🙂

Quickstart

Installation

Install Django Serverless Cron:

pip install django-serverless-cron

Settings

Add it to your `INSTALLED_APPS`:

INSTALLED_APPS = (
    # ...
    'django_serverless_cron'
    # ...
)

Add jobs to your settings file:

SERVERLESS_CRONJOBS = [
    # (
    #   '1_hours',                       # frequency (seconds, minutes, hours, days, weeks) -> in this case, every one hour
    #   'mail.jobs.send_mail_function',  # path to task/function functions -> in this case, send_mail_function()
    #   {'kwarg1': 'foo'}                # kwargs passed to the function
    # ),
    (
        '1_days',
        'your_app.services.your_job_function',
        {'kwarg1': 'foo', 'kwarg2': 'bar', "is_bulk": True}
    ),
    (
        '1_hours',
        'mail.jobs.send_mail_function',
        {}                               # job without kwargs
    ),
]

URL patterns

Add the jobs to your URL patterns:

from django.urls import path, re_path, include #add re_path and include
from django_serverless_cron import urls as django_serverless_cron_urls


urlpatterns = [
    # ...
    re_path(r'^', include(django_serverless_cron_urls)),
    #...
]

Migrate

python manage.py migrate

Running Jobs

In Development

Running Jobs through HTTP requests

Call the [/run]{.title-ref} path to run all jobs:

Example:

curl http://localhost:8000/run

import requests

x = requests.get('http://localhost:8000/run')

Running Jobs through the management command

This will run the jobs every 30 seconds:

python manage.py serverless_cron_run

You can alternatively add the [--single_run=\'True\']{.title-ref} option to run the jobs just once.

In Production

Similar to in development, we can call the [/run]{.title-ref} path via fully managed services which are usually ridiculously cheap. Examples:

https://cloud.google.com/scheduler -> Great feature set, easy to use, reasonable free tier & very cheap.
https://aws.amazon.com/eventbridge
https://azure.microsoft.com/en-gb/services/logic-apps formerly https://docs.microsoft.com/en-us/azure/scheduler/scheduler-intro
https://cron-job.org/en/ -> Absolutely free and open-source: https://github.com/pschlan/cron-job.org
https://www.easycron.com
https://cronhub.io
https://cronless.com -> Has 30 Second Cron Jobs
https://github.com/features/actions; https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#onschedule -> eg making a HTTP request using [curl]{.title-ref} in a step
https://www.cronjob.de
https://zeplo.io
https://catalyst.zoho.com/help/cron.html
https://www.cronjobservices.com

Related media

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Credits

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