Clients get the `Can't get Master Kerberos principal` error message when their config doesn't identify the principal for a service.
This message is fairly useless as
- it doesn't identify the service for which a principal is sought
- it doesn't identify the configuration property looked for
- it doesn't provide any guidance of how to fix it
As a result, anyone seeing this doesn't have a clue what to do.
- naming the principal sought, e.g. "namenode", "YARN RM"
- naming the configuration item looked for
- adding a link to a wiki page covering the problem
KDiag should scan through the common set of principals if it doesn't already