* Dynamic Configuration (ConfigMap API in the core API group) enables application
configuration to be stored as a Kubernetes API object and pulled dynamically on
container startup, as an alternative to baking in command-line flags when a
container is built.
     * Turnkey Deployments (Deployment API (Beta) in the Extensions API group)
automate deployment and rolling updates of applications, specified

* [Breaking change, client-go]: The WaitFor function returns, probably an ErrWaitTimeout, when the done channel is closed, even if the `WaitFunc` doesn't handle the done channel. ([#72364](https://github.com/kubernetes/kubernetes/pull/72364), [@kdada](https://github.com/kdada))

- The `kube-proxy` command-line documentation was updated to clarify that
  `--bind-address` does not actually have anything to do with binding to an

  * Setting TLS1.2 minimum
  * `kubectl create secret tls` command
  * Webhook Token Authenticator
  * **beta** PodSecurityPolicy objects limits use of security-sensitive features by pods.
* Kubectl
  * Display line number on JSON errors
  * Add flag -t as shorthand for --tty
* Resources

    * `kubectl create secret` has a new option `--from-env-file` that populates a secret from file which follows a key=val format for each line.

  * Printing/describe

### Bug or Regression

- Fix component status calling etcd health endpoint over http which exposed kubernetes to the risk of complete watch starvation and is inconsistent with other etcd probing done by kube-apiserver. ([#119038](https://github.com/kubernetes/kubernetes/pull/119038), [@serathius](https://github.com/serathius)) [SIG API Machinery]