Code review comment for lp://qastaging/~vladimir.p/nova/admin-vm

Since this is a relatively major feature, I would like to see the blueprint expanded to describe the implementation. In particular, I want to hear why adding a 'category' to an instance is the right path to take. Why not use the metadata container?

This could also be considered an admin-only feature that doesn't belong in the end-user apis. I'm not crazy about seeing undocumented changes to the OpenStack API.

I'm pretty excited about this feature, I just want to make sure we are doing it right :)