Running cron python jobs within docker

Question

I would like to run a python cron job inside of a docker container in detached mode. My set-up is below:

My python script is test.py

#!/usr/bin/env pyt         


        

Answer 1

Adding crontab fragments in /etc/cron.d/ instead of using root's crontab might be preferable.

This would:

• Let you add additional cron jobs by adding them to that folder.
• Save you a few layers.
• Emulate how Debian distros do it for their own packages.

Observe that the format of those files is a bit different from a crontab entry. Here's a sample from the Debian php package:

# /etc/cron.d/php5: crontab fragment for php5
#  This purges session files older than X, where X is defined in seconds
#  as the largest value of session.gc_maxlifetime from all your php.ini
#  files, or 24 minutes if not defined.  See /usr/lib/php5/maxlifetime

# Look for and purge old sessions every 30 minutes
09,39 *     * * *     root   [ -x /usr/lib/php5/maxlifetime ] && [ -x /usr/lib/php5/sessionclean ] && [ -d /var/lib/php5 ] && /usr/lib/php5/sessionclean /var/lib/php5 $(/usr/lib/php5/maxlifetime)

Overall, from experience, running cron in a container does work very well (besides cron logging leaving a lot to be desired).