The problem of Kerberos is that is not easy to configure and multiple times results in the well known Anonymous Logon Error, aka Double Hop.
That’s why you will find plenty of IIS and other applications out there, using SQL logins (Impersonation Users), because Windows Authentication can be really frustrating and applications won’t be able to connect to SQL Server otherwise.
There are multiple resources in the internet that explain the Double-Hop issue, so that won’t be the scope of this post, but I will show how to correctly configure SPNs to SQL Server Availability Groups, which is the first link in the Kerberos chain.
Kubernetes isn’t the only place where you’ll find the need to set SPNs, either.