Code review comment for lp:~usc-isi/nova/instance_type_extra_specs

Migration number has been bumped.

This code shouldn't affect the api (at least, not the user api). From a user's point of view, they are just requesting an instance type by name. For example, if you wanted a compute node with GPUs, the user would request something like a "cg1.4xlarge" instead of an "m1.large".

(Somebody needs to add the gpu-related metadata to cg1.4xlarge instance type, but this will be site-specific. Is there currently an admin api for adding/modifying instance types? I assumed that this was currently done by just modifying the database directly. We'd ultimately like to modify the dashboard to allow an admin to edit this type of content).

To use this data:

- The compute service needs to report its capabilities (this code is already there)
- The scheduler needs to check if an instance type's metadata matches a compute service's capabilities. (the distributed scheduler code has some generic facilities for filtering, we would just filter on the instance type metadata if it is present).