New KVM Ohai Plugin

I wrote a new KVM plugin for Ohai which gives a ton of important information about KVM guests, which is stored in the node attributes for the host.  This makes it easy to find out which guests are currently on a host and other information about the guest, such as: cpu allocation, memory usage, persistence, autostart, etc.

One of the things you can do once you have this plugin installed and running on the host is have the guest perform a search to find it’s host and then save that information somewhere on the guest. ┬áThis is very convenient if you’re on a kvm guest and you want to know right away what it’s host is.

In you Chef code, just use something like this to find the current guest’s host:

parent_host = search(:node, "virtualization_kvm_guests:#{node[:hostname]}").first

This plugin uses the same naming scheme for listing guests as my Linux VServer Ohai plugin, so it’s easy to search for the host of a guest, regardless of virtualization type. I often find myself using knife to search for the host of a guest using this:

knife search node "virtualization_*_guests:<myguestname>"

I think of this as a poor man’s KVM management system. ;)


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