Ubuntu latest with cron, powerd by supervisor.
You can easily replace the default
/etc/crontab with one that suits your needs.
The image will log the syslog into stdout which makes it easy for you to
inspect the logs with
docker logs <container>.
If you want that other files also appear in the stdout, you can set the environment
FILES_TO_LOG with a semicolon separated list of files to log (eg.