support alternatives to default (rtl8139) NIC type

[tdilauro]

Introduces new flag: --kvm-nic-type

Example command line:

docker-machine create -d kvm --kvm-network "docker-machines" --kvm-nic-type virtio local

[benroose]

Dear Tim DiLauro,
I hope you are able to see this comment. I wanted to open an issue directly on your GItHub fork of Daniel Hiltgen's docker-machine-kvm project, but you seem to have issues disabled on your fork.

To use the docker-machine KVM driver with your new --kvm-nic-type option, I am adding your updated version into an Ansible role for automated installing of docker-machine with the KVM driver on a RHEL system. However, I'd ultimately like to set the Ansible role for downloading this KVM driver from an official upstream repo.

Looking at issue #67 for this repo (Finding new home for docker-machine KVM driver), it seems Daniel has handed this project over to a community-based repo located at machine-drivers/docker-machine-driver-libvirt.

Would you consider forking from the newer machine-drivers libvirt repo and then formally submitting a pull request to their repo for integration of this new (and greatly needed) --kvm-nic-type feature?

Thanks so much for adding the new feature and I really hope it can be merged into the continued libvirt driver!

Best regards,
Ben

[xZero707]

@tdilauro Great work. Unfortunately doesn't work anymore.
Accordingly to my debugging, this must be the reason (although old): https://bugzilla.redhat.com/show_bug.cgi?id=1228631

I cannot find any .leases file where driver is looking for.
Interestingly, it doesn't seem to fail with "Failed to retrieve dnsmasq leases" like I expected it to. No data is loaded, just empty string.

[xZero707]

@benroose Unfortunately, guys decided to abandon the project (although unofficially) and instead maintain "kvm2" which is not a separate driver anymore, but rather part of minikube project.