How to run a cron job inside a docker container?

Question

I am trying to run a cronjob inside a docker container that invokes a shell script.

Yesterday I have been searching all over the web and stack overflow, but I could

Answer 1

Cron jobs are stored in /var/spool/cron/crontabs (Common place in all distros I Know). BTW, You can create a cron tab in bash using something like that:

crontab -l > cronexample
echo "00 09 * * 1-5 echo hello" >> cronexample
crontab cronexample
rm cronexample

This will create a temporary file with cron task, then program it using crontab. Last line remove temporary file.