Fetching the default IaaS host

I've been try to get the default IaaS host from an action (to populate dynamic forms in a blueprint). the following code simply returns "undefined":

var host = Server.findAllForType("vCAC:VCACHost")[0];

System.log("found: "+host.displayName);

I sure i'm missing something basic - but i assumed that the IaaS host would be available..

Thanks!