Support for the "network_config" interfaces template.

Is there a way to tell tempest somehow to include the "network_config" field in the metadata (configdrive/httpservice/ec2) like this one shown in this[1] example? All I managed to do is to include files through the "personality" parameter when creating the server[2], but what I need is to include my content as a network_config specific object (the one that comes from the debian-like interfaces template).

[1]: http://sprunge.us/cNZW
[2]: http://sprunge.us/AWcb