Problem description
===================
It is not possible to create multiple rating types
for the same metric in Gnocchi, which forces operators
to create multiple metrics for the same resource type in
Gnocchi to create different rating types in Cloudkitty for
the same resource type in Gnocchi.
Proposal
========
We propose to extend the Gnocchi collector to allow operators
to create multiple rating types for the same metric in Gnocchi.
Using this approach we can create, for example, a rating type
for software licenses in a running instance and another rating
type for the instance flavor; it can be implemented using only
one metric in Gnocchi which has the instance installed softwares
and flavor metadata.
Change-Id: I69d4ba14cc72ba55e47baa6fd372f2085e1124da
7966437397