virtualmin-base gives the following error for Apache setup, if the hostname of the server isn't discoverable via DNS:
Failed to start Apache!
Starting Apache manually with "service httpd start" after the install completes succeeds but with an error:
[root@fc4 ~]# service httpd start
Starting httpd: httpd: Could not determine the server's fully qualified domain name, using 127.0.0.1 for ServerName
[ OK ]
I'm guessing this is why things don't quite work out, and we get an error report. This seems to lead to other weirdness, which I haven't tracked down yet (i.e. Virtualmin doesn't detect that Apache has been setup, but browsing to the Apache module and back again without touching anything leads to Virtualmin deciding it is setup...I can't even imagine how that could happen!).
This is, probably, an edge case, but we need to handle it without giving an error and without leading to other failures, which this seems to trigger. I'm still looking into just what of the other problems I'm seeing are caused by the and what are caused by something else.