Description of problem:
spacewalk-setup and spacewalk-hostname-rename presently only detect the
shortname as would be returned by "uname -n", not the FQDN as would be
detected by checking /etc/hosts, or a reverse DNS lookup in a correctly configured DNS environment.

This causes SSL verification failure when clients make a request against
against the FQDN. The SSL certificate has components populated with the shortname rather than FQDN, and as such verification fails when clients provide the FQDN because it doesn't match the shortname found in the SSL cert.

It also causes the Spacewalk server name to be populated with the shortname
which can cause problems for client registration and Inter Server
Synchronisation AuthN.

spacewalk-setup and spacewalk-hostname-rename should attempt to obtain the
FQDN and only fallback to providing the shortname if all attempts to identify
the FQDN fails.

Version-Release number of selected component (if applicable):
All

How reproducible:
On a system with the shortname in /etc/hostname or /etc/sysconfig/network, run spacewalk-setup or spacewalk-hostname-rename. The shortname will be detected and used to populate components of the SSL certificate.