The problem is to install a linux server without touching the system. Ok, ok, I at least need that someone enters the CD into the linux box, but this is all I would need. The idea behind is that in on today's datacenters, physical access is complicated, or even impossible: you have to contract “remote hands” in order to make simple things that can't be done remotely.

Of course, I've started with a virtual linux installation to see how it is done. You have to use the “bridge” network adapter in order to access remotely to the machine, because it gives a real IP of your local network, and so the virtual computer will be accesible through internet.

In the virtual machine there should be mounted a CD (or an ISO image) of the new server.

Log into the machine with ssh -X and mount the CD:

root@ubuntu:/media# mount /dev/cdrom /mnt/
mount: block device /dev/sr0 is write-protected, mounting read-only

And run cdromupgrade:

rluna@ubuntu:/mnt$ sudo ./cdromupgrade 
Checking package manager

Continue running under SSH? 

This session appears to be running under ssh. It is not recommended 
to perform a upgrade over ssh currently because in case of failure it 
is harder to recover. 

If you continue, an additional ssh daemon will be started at port 
'1022'. 
Do you want to continue? 

Continue [yN] 

Answer yes, of course. The process of install will start. Answer the questions as usual:

To continue please press [ENTER]

Reading package lists... Done
Building dependency tree        
Reading state information... Done
Building data structures... Done 
[....]

After the process, the machine reboots effortessly, so it can be done this way.