- Updated `kube-openapi` to remove invalid defaults: OpenAPI spec no longer includes default of `{}` for certain fields where it did not make sense. ([#120757](https://github.com/kubernetes/kubernetes/pull/120757), [@alexzielenski](https://github.com/alexzielenski))

a single one that can proceed is chosen via a uniform pseudo-random selection.
Otherwise, if there is a default case, that case is chosen.
If there is no default case, the "select" statement blocks until
at least one of the communications can proceed.
</li>

<li>
Unless the selected case is the default case, the respective communication
operation is executed.
</li>

<li>

### Bug or Regression

- Disabled a previously on-by-default optimization for the API server where each **watch** response used a dedicated goroutine. The `APIServingWithRoutine` feature gate has been demoted from beta to alpha, and is now off by default. ([#126481](https://github.com/kubernetes/kubernetes/pull/126481), [@benluddy](https://github.com/benluddy)) [SIG API Machinery]

  - `failurePolicy` default changed from `Ignore` to `Fail` for v1
  - `matchPolicy` default changed from `Exact` to `Equivalent` for v1
  - `timeout` default changed from `30s` to `10s` for v1
  - `sideEffects` default value is removed, and the field made required, and only `None` and `NoneOnDryRun` are permitted for v1

yfujita <******@****.***> 1483671689 +0900

yfujita <******@****.***> 1533310816 +0900

yfujita <******@****.***> 1499063604 +0900

([#58171](https://github.com/kubernetes/kubernetes/pull/58171), [@verult](https://github.com/verult))

* Default values differ between the Kubelet's componentconfig (config file) API and the Kubelet's command line. Be sure to review the default values when migrating to using a config file. For example, the authz mode is set to "AlwaysAllow" if you rely on the command line, but defaults to the more secure "Webhook" mode if you load config from a file. ([#59666](https://github.com/kubernetes/ku...

### Volumes
* StorageClass pre-installed and set as default on Azure, AWS, GCE, OpenStack, and vSphere.
  * This is something to pay close attention to if you’ve been using Kubernetes for a while, because it changes the default behavior of PersistentVolumeClaim objects on these clouds.

  * Special notice for kube-proxy in 1.7+ (including 1.7.0):
    * Healthz server (/healthz) will be served on 0.0.0.0:10256 by default.
    * Metrics server (/metrics and /proxyMode) will be served on 127.0.0.1:10249 by default.
    * Metrics server will continue serving /healthz.


# v1.7.2