Mara Cron

Mini package for managing cron jobs via mara.

 

Installation

To use the library directly:

pip install mara-cron

 

Config of cron jobs

To configure cron jobs in mara you just need to add a new function MARA_CRON_JOBS in your module or app in the __init__.py file.

Here is a sample which has two jobs:

1. the job cleanup_data_folder clears all data from the local folder /data/. This job is by default disabled.
2. the job nightly runs the root pipeline at 01:00 o'clock each day

Note: The MaraJob job requires that you define the PATH environment variable in your crontab. Cron by default uses just /usr/bin:/bin which is not enough. I recommend using the distribution default e.g. /usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin.

def MARA_CRON_JOBS():
    from mara_cron.job import CronJob, MaraJob
    return [
        CronJob(id='cleanup_data_folder',
                description='Clean up the data folder',
                default_time_pattern='0 0 * * *',
                command='rm -rf /data/*',
                enabled=False),
        MaraJob(id='nightly',
                description="Nightly run of the BI system",
                default_time_pattern='0 1 * * *',
                command='pipelines run'),
    ]

Local config

Sample local config to activate crontab management in your mara app:

from mara_app.monkey_patch import patch
import mara_cron.config

# Activates mara_cron jobs. If not set all jobs are
# by default disabled and can only be activated via
# executing:
#    mara cron enable --job-id "my_job_id"
patch(mara_cron.config.enabled)(lambda: True)

# Optional parameter to specify a mara instance name
# This is necessary to separate multiple environments running
# on the same user
patch(mara_cron.config.instance_name)(lambda: 'prod')

CLI

This package contains the following cli commands (mara cron <command>):

Command	Description
enable --job-id "my_job_id" [--module "module_name"]	Enables a specific job regardless of the configuration.
disable --job-id "my_job_id" [--module "module_name"]	Disables a specific job.
schedule-job --job-id "my_job_id"	Schedules a job to run in less than 1 minute.
list-crontab	Lists the current cron tab settings
list-crontab --with-changes	Lists the current cron tab including the changes not yet written
write-crontab	Writes all not published changes to the crontab
clear-crontab	Removes all mara jobs from the crontab. Note This applies to all instances !!!