There is a fantastic tutorial here from spinlocksolutions that walked you through how to set up a Kerberos server and service on a Debian based box.

Kerberos is critical for building a robust and secure environment where it has been giving me a hard time since day one. I am planning to follow up with the tutorial as much as I can on a few Ubuntu VMs on AWS and hopefully in the end understand all the Kerberos or Security jargon and solve the problem.