about

dead simple crontab powered job scheduling for django.

setup

install via pip:

pip install django-crontab

add it to installed apps in django settings.py:

INSTALLED_APPS = (
    'django_crontab',
    ...
)

now create a new method that should be executed by cron every 5 minutes, f.e. in myproject/myapp/cron.py:

def my_scheduled_job():
  pass

now add this to your settings.py:

CRONJOBS = [
    ('*/5 * * * *', 'myproject.myapp.cron.my_scheduled_job')
]

you can also define positional and keyword arguments which let you call django management commands:

CRONJOBS = [
    ('*/5 * * * *', 'myproject.myapp.cron.other_scheduled_job', ['arg1', 'arg2'], {'verbose': 0}),
    ('0   4 * * *', 'django.core.management.call_command', ['clearsessions']),
]

finally run this command to add all defined jobs from CRONJOBS to crontab (of the user which you are running this command with):

python manage.py crontab add

show current active jobs of this project:

python manage.py crontab show

removing all defined jobs is straight forward:

python manage.py crontab remove

config

there are a bunch of setting vars to customize behavior. each of this comes with default values that should properly fit. if not, feel free to overwrite.

CRONJOBS

• list of jobs, each defined as tuple:

  • format 1:
    1. required: cron timing (in usual format: http://en.wikipedia.org/wiki/Cron#Format)
    2. required: the python module path to the method
    3. optional: a job specific suffix (f.e. to redirect out/err to a file, default: '')
  • format 2:
    1. required: cron timing (in usual format: http://en.wikipedia.org/wiki/Cron#Format)
    2. required: the python module path to the method
    3. optional: list of positional arguments for the method (default: [])
    4. optional: dict of keyword arguments for the method (default: {})
    5. optional: a job specific suffix (f.e. to redirect out/err to a file, default: '')

• NOTE: Run "python manage.py crontab add" each time you change CRONJOBS in any way!

• default: []

• example:

  CRONJOBS = [
      ('*/5 * * * *', 'myproject.myapp.cron.my_scheduled_job'),
  
      # format 1
      ('0   0 1 * *', 'myproject.myapp.cron.my_scheduled_job', '> /tmp/last_scheduled_job.log'),
  
      # format 2
      ('0   0 1 * *', 'myproject.myapp.cron.other_scheduled_job', ['myapp']),
      ('0   0 * * 0', 'django.core.management.call_command', ['dumpdata', 'auth'], {'indent': 4}, '> /home/john/backups/last_sunday_auth_backup.json'),
  ]
  

CRONTAB_LOCK_JOBS

• prevent starting a job if an old instance of the same job is still running
• default: False
• since 0.5.0

CRONTAB_EXECUTABLE

• path to the crontab executable of your os
• default: '/usr/bin/crontab'

CRONTAB_DJANGO_PROJECT_NAME

• the name of your django project, used to build path path to manage.py and to mark the jobs in contrab via comment for later removing
• default is read from DJANGO_SETTINGS_MODULE environment variable

CRONTAB_DJANGO_MANAGE_PATH

• path to manage.py file (including the manage.py itself, i.e. '/home/john/web/manage.py')
• default is build using DJANGO_PROJECT_NAME

CRONTAB_PYTHON_EXECUTABLE

• path to the python interpreter executable used to run the scheduled job
• default uses the interpreter executable used to add the jobs (via 'python manage.py crontab add')

CRONTAB_COMMAND_PREFIX

• something you wanne do or declare before each job gets executed. A good point for environment variables.
• default: '' (empty string)
• example: 'STAGE=production'

CRONTAB_COMMAND_SUFFIX

• something you wanne do after each job was executed.
• default: '' (empty string)
• example: (do you know a good example?)

CRONTAB_COMMENT

• used for marking the added contab-lines for removing, default value includes project name to distinguish multiple projects on the same host and user
• default: 'django-crontabs for ' + CRONTAB_DJANGO_PROJECT_NAME

contributors

arski cinghiale meric426

license

MIT-License, see LICENSE file.