Comment 1 for bug 1531502

To summarize, the issue is that we *can't* enforce child default quotas. The reason for this is because during actions like volume create (where we need to enforce quotas), we do not grab the parent_id for the project. However, since create volume is a non-admin action, we can't simply ask Keystone for the current project to get it's parent_project_id.

To solve this we are looking into the following (in preference order):
   1) Adding parent_project_id to the Keystone token
   2) Adding non-admin command in Keystone to retrieve parent_project_id
   3) Use Cinder's "service" user

We will also discuss the general design for NestedQuotas to see if there's any changes we think should be made