I think they way I approached it is a lot more flexible for this type of configuration, where there is a config[:server_create] and you specify what you need to create a server rather than a hodgepodge of configuration values.  See server_create section in the https://github.com/TerryHowe/kitchen-fog/blob/master/README.md#usage  I did the same thing authentication.  It forces the user to have a bit more understanding of Fog, but a million times more flexible.  I'd merge my changes back, but they seem a bit out of place because this project is focused on openstack.