New backend: Deploy to booted minimal live NixOS CD

[HittingSmoke]

I was surprised to not see this in the docs after tinkering around a bunch with NixOps today.

It would be great if one of the deploy target options was a booted live CD.

As in, I upload the minimal install media to my VPS and boot it. Select "NixOps Deploy" which would put it in a state of waiting for a NixOps client to connect.

Then back at my main PC I can run a NixOps deployment pointed at the IP address of the VPS that is booted into the live environment and NixOps deploys NixOS on the first hard drive detected.

NixOps is awesome, but supporting only three actual hosting services makes it extremely limited.

[domenkozar]

I've deleted my previous misunderstood comments and renamed the issue to reflect the desired feature request.

[domenkozar]

I think this wouldn't be too hard to implement with existing Hetzner backend as it does pretty much the same thing.

It's sensible to implement it once we have https://github.com/aszlig/nixpart 1.0 released with ability to specify partition formatting in Nix.

cc @aszlig