Keeping a tap on virtual machines

Ok, I'm close to admitting defeat now. I can't keep track of all of the virtual machines that are created around me. The fact that we are using VMware ESX, VMware Server, Xen, and KVM all together does not make the job easier. Just keeping an overview of what runs on which server, which IP addresses are used, and which credentials are needed to access them fills up a big table in a wiki page already. Just keeping that page updated is a struggle. There are of course specific tools (some nicer, some not so) for each of the virtualization solutions, but I still have to find the One Tool To Rule Them All, One Tool To Find Them, One Tool To Bring Them All And In The Darkness Bind Them!

So right now, I'm more often than not, accessing all the different server consoles and trying to find the machine that I'm looking for. Also, while the VMware virtualization center is nice and easy to use, it does not show you the IP addresses of the machines. Logging in to each of them through the console is time-consuming. Using IP addresses as names helps though, so that is what I started doing (obviously only for machines with static IPs).

Getting IP addresses for Xen guests is easier because the configuration files actually contain the IP addresses. There is a way to get current IP addresses from VMware guests as well, but they have to be running and they have to have VMware tools installed. VM tools are a high hurdle, especially for non-mainstream operating systems where you have to download, compile and install the tools yourself. An alternative is to look into the ARP and forwarding tables of the upstream switch and search for the IP address based on the MAC address (which you can get e.g. through the VC client). You have to make sure though, that the machine is in the ARP table, so that creates a chicken-and-egg problem. If you know at least the subnet of the machine and that subnet is not too big (/24 works fine), you can fill the table by fping-ing the range.