It is an alpha feature but you can switch the rkt "stage1" using the rkt.alpha.kubernetes.io/stage1-name-override annotation on a pod. So if you wanted to use

It is an alpha feature but you can switch the rkt "stage1" using the rkt.alpha.kubernetes.io/stage1-name-override annotation on a pod. So if you wanted to use the virtual machine based pod isolation you could do something like rkt.alpha.kubernetes.io/stage1-name-override=coreos.com/rkt/stage1-kvm:1.10.0. We are working with upstream to come up with a better mechanism but this is a great example of where having an annotation is a great release valve for adding experimental features.