- **Federation**
  - [alpha] Support for ConfigMaps in federation. ([docs](http://kubernetes.io/docs/user-guide/federation/configmap/)) ([kubernetes/features#105](https://github.com/kubernetes/enhancements/issues/105))

- Kubeadm: increased the verbosity of API client dry-run actions during the subcommands "init", "join", "upgrade" and "reset". Allowed dry-run on 'kubeadm join' even if there is no existing cluster by utilizing a faked, in-memory cluster-info ConfigMap. ([#126776](https://github.com/kubernetes/kubernetes/pull/126776), [@neolit123](https://github.com/neolit123)) [SIG Cluster Lifecycle]

* Add density (batch pods creation latency and resource) and resource performance tests to `test-e2e-node' ([#29764](https://github.com/kubernetes/kubernetes/pull/29764), [@coufon](https://github.com/coufon))
* Allow Secret & ConfigMap keys to contain caps, dots, and underscores ([#25458](https://github.com/kubernetes/kubernetes/pull/25458), [@errm](https://github.com/errm))