### Juju
* The kubernetes-master, kubernetes-worker and kubeapi-load-balancer charms have gained an nrpe-external-master relation, allowing the integration of their monitoring in an external Nagios server. ([#41923](https://github.com/kubernetes/kubernetes/pull/41923), [@Cynerva](https://github.com/Cynerva))

- This change picks up the latest GCE pinhole firewall feature, which introduces destination-ranges in the ingress firewall-rules. It restricts the access to the backend IPs via allowing traffic via allowing traffic through ILB or NetLB IP only. This change does NOT change the existing ILB or NetLB behavior. ([#109510](https://github.com/kubernetes/kubernetes/pull/109510), [@sugangli](https://github.com/sugangli)) [SIG API Machinery, Architecture,...

- The following deprecated metrics are removed, please convert to the corresponding metrics:
  - The following replacement metrics are available from v1.14.0:
      - `rest_client_request_latency_seconds` -> `rest_client_request_duration_seconds`

### CSI Proxy for Windows

The CSI Proxy for Windows is being promoted to beta along with the 1.19 release. This CSI Proxy enables CSI Drivers to run on Windows by allowing containers in Windows to perform privileged storage operations. At beta, the CSI Proxy for Windows supports storage drivers using direct attached disks and SMB.

### Dashboard v2

  // Some pod and container fields are restricted if this is set.
  //
  // If the OS field is set to linux, the following fields must be unset:
  // -securityContext.windowsOptions
  //
  // If the OS field is set to windows, following fields must be unset:
  // - spec.hostPID
  // - spec.hostIPC
  // - spec.hostUsers
  // - spec.securityContext.seLinuxOptions

- Autoscaling/v2beta2 and custom_metrics/v1beta2 have been introduced, which implement metric selectors for Object and Pods metrics, as well as allowing AverageValue targets on Objects, similar to External metrics. ([#64097](https://github.com/kubernetes/kubernetes/pull/64097), [@damemi](https://github.com/damemi)) Courtesy of SIG API Machinery, SIG Architecture, SIG Autoscaling, SIG CLI, and SIG...

support for concurrent programming.  Programs are constructed from
<i>packages</i>, whose properties allow efficient management of
dependencies.
</p>

<p>
The grammar is compact and simple to parse, allowing for easy analysis
by automatic tools such as integrated development environments.
</p>

<h2 id="Notation">Notation</h2>
<p>
The syntax is specified using Extended Backus-Naur Form (EBNF):
</p>

- Add --permit-address-sharing flag to `kube-apiserver` to listen with `SO_REUSEADDR`. While allowing to listen on wildcard IPs like 0.0.0.0 and specific IPs in parallel, it avoids waiting for the kernel to release socket in `TIME_WAIT` state, and hence, considerably reducing `kube-apiserver` restart times under certain conditions. ([#93861](htt...

With CSI the Kubernetes volume layer becomes truly extensible, allowing third party storage developers to write drivers making their storage systems available in Kubernetes without having to touch the core code.

modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation