With the goal of slimming down the size of our atomic host image and of allowing users the flexibility to choose different component versions, we removed kubernetes and few other packages from the continuous/alpha version of centos atomic host back in august[1].
[1] https://github.com/CentOS/sig-atomic-buildscripts/commit/3ce19d58a5f1d9b5d54...
Fedora made a similar change[2] in Fedora Atomic 25.
[2] https://pagure.io/fedora-atomic/c/219c9bb26426811a5f32188c59682ad70c3283e5
RHEL Atomic host, in the 7.3 version, went halfway and removed the master half of kubernetes, but left the node half of the package in place. When we update the downstream version of CentOS Atomic Host, if we follow the lead of RHEL AH, we'll be pinned to kubernetes 1.3 for the kubelet and kube-proxy, and we'll have to run the master components in containers.
I want to discuss diverging from RHEL AH by not including the kubernetes-node pkg in our downstream image. This would allow users to install a newer version of the kubernetes-node, such as this 1.4.5 version from my copr[3] that I hope to see move into the virt-sig soon.
[3] https://copr.fedorainfracloud.org/coprs/jasonbrooks/kubernetes/
The 1.3 kube would still be available in the extras repo (once it's built), and users will have the option of installing that one, if they choose, using package layering. [4]
[4] http://www.projectatomic.io/blog/2016/07/hacking-and-extending-atomic-host/
Either way, we'll need to document this, and I'm working on those docs now.
Jason