Comment 16 for bug 1718747

> The user side actually worries me less than the project side: deleting a project without deleting the resources in the remote services leave them unmanageable and require a system level admin to clean them up with some global scope of responsibility.

That's not really our problem. We have to support deleting projects, and yes if you delete a project that still has a nova server in it then you're going to need to clean that up. That's already the case today and not the focus of this bug.

> Do we really want to do this?

Letting keystone emit a 500 is not an option, we either need to fix the old behavior or change the behavior to emit a validation error. We might be in a gray area now that we've already broken it but in general switching the response from a 2XX to a 4XX is not okay.