Ignore SR-IOV interfaces on Azure

[bgilbert]

Container Linux ships a networkd unit to ignore SR-IOV interfaces on Azure. This is a cosmetic issue; such interfaces won't actually return packets and will never finish configuring.

Implement this via a mechanism consistent with the outcome of #24.

[dustymabe]

This is a cosmetic issue; such interfaces won't actually return packets and will never finish configuring.

is this a bug in the platform and we are just protecting our users?

[bgilbert]

The way SR-IOV is implemented on Azure, there's the base NIC functionality and then there's a high-performance mode that shows up as a separate NIC. The latter is automatically bonded to the former by the kernel driver, but is still visible to userspace even though it doesn't function on its own.

[lucab]

@bgilbert I think this was addressed by coreos/fedora-coreos-config#121 and can be closed.

[bgilbert]

@lucab Yup!