Comment 5 for bug 1524745

I have a concern that the hardware_type defaults imply a interface implementation is enabled, and therefore supported by a particular deployment of Ironic. This may not be the case for example:

hardware_type X:
supported_FOO_interfaces: [BAR, RAR]
default_FOO_interface: BAR

A deployer knows BAR doesn't work in their environment, but wants to support hardware_type X using RAR. So he enables hardware_type X. In the current spec enabling X automatically enables BAR because its the default even though it might not be supported.

This then means that someone using Ironic can create a node using BAR even though it is known not to work in this deployment. And worse than that is, if the person using Ironic doesn't override it the node will be created with BAR by default, resulting in a broken node by default.