Add an inherit_kerberos role

[wbclark]

The role installs kerberos client packages and optionally copies the configuration and credential cache from the host machine.

[wbclark]

I've rewritten this to use the when: pathname is defined pattern

[evgeni]

Added some minor comments. Would be cool if there would be a few lines in the readme, how to use this role?

[wbclark]

@evgeni some additional context --

The goal of these efforts is to create a portable hotfix environment which is fully encoded in a block of yaml so that other developers can simply copy & paste the box, edit as needed, and vagrant up

I could add a very basic README.md for the role if that is what we need to get it merged. The lack of documentation in this project is a real concern. If we do not also follow through on documenting the other roles then I am not sure whether it is worth documenting this one, and I don't have tons of time to devote to that larger effort at present.

What do you think?

[ekohl]

I could add a very basic README.md for the role if that is what we need to get it merged. The lack of documentation in this project is a real concern. If we do not also follow through on documenting the other roles then I am not sure whether it is worth documenting this one, and I don't have tons of time to devote to that larger effort at present.

I think a policy where we document new roles is a good start.

On a related matter I opened https://github.com/theforeman/forklift/pull/1568. It doesn't document the ansible roles, but that could be a nice addition.

[evgeni]

I agree that the roles are under-documented, even if most roles are not designed to be used on their own, but are rather abstractions most users shouldn't have to care about.

If you say these are building blocks, and you will provide the "full" workflow later, I am cool with adding the docs for that feature later too.