[Enhancement] Auth with a Kerberos User

[calibrae]

On most of my machines, auth is handled by sssd by the way of FreeIPA.
Therefore, accounts do not reside in /etc/shadow, hence I get a permission denied when trying to login.

root user, existing in /etc/shadow, logon successfully.

A correct way to auth users on linux machine would be to use pam.d .

[gustavosbarreto]

A correct way to auth users on linux machine would be to use pam.d .

For the docker version, maybe we need to implement this as well?

https://jhrozek.wordpress.com/2015/03/31/authenticating-a-docker-container-against-hosts-unix-accounts/