* Docker versions as old as may 1.9.1 work with [known issues](CHANGELOG.md#191) but this is not guaranteed
* rkt version 1.21.0
  * known issues with the rkt runtime are [listed here](http://kubernetes.io/docs/getting-started-guides/rkt/notes/)
* etcd version 2.2.1

* Add get/delete cluster, delete context to kubectl config ([#29821](https://github.com/kubernetes/kubernetes/pull/29821), [@alexbrand](https://github.com/alexbrand))
* rkt: Force `rkt fetch` to fetch from remote to conform the image pull policy. ([#31378](https://github.com/kubernetes/kubernetes/pull/31378), [@yifan-gu](https://github.com/yifan-gu))