- Supporting Cross RG resources (disks, Azure File and node [Experimental]

Besides the above new features, support for Azure Virtual Machine Scale Sets (VMSS) and Cluster-Autoscaler is now stable and considered GA:

- Azure virtual machine scale sets (VMSS) allow you to create and manage identical load balanced VMs that automatically increase or decrease based on demand or a set schedule.

* Adds a new `kubeadm config` command that lets users tell `kubeadm upgrade` what kubeadm configuration to use and lets users view the current state. ([#50980](https://github.com/kubernetes/kubernetes/pull/50980), [@luxas](https://github.com/luxas))

- Exposes and sets a default timeout for the SubjectAccessReview client for DelegatingAuthorizationOptions ([#96152](https://github.com/kubernetes/kubernetes/pull/96152), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery and Cloud Provider]

- Exposes and sets a default timeout for the SubjectAccessReview client for DelegatingAuthorizationOptions ([#96153](https://github.com/kubernetes/kubernetes/pull/96153), [@p0lyn0mial](https://github.com/p0lyn0mial)) [SIG API Machinery and Cloud Provider]

### Bug or Regression

- Fixes a race condition in the iptables mode of kube-proxy in 1.27 and later
  that could result in some updates getting lost (e.g., when a service gets a
  new endpoint, the rules for the new endpoint might not be added until
  much later). ([#122757](https://github.com/kubernetes/kubernetes/pull/122757), [@hakman](https://github.com/hakman)) [SIG Network]

failure.
  * “kubectl rolling-update” only supports Replication Controllers (it doesn’t
support Replica Sets). It’s recommended to use Deployment 1.2 with “kubectl
rollout” commands instead, if you want to rolling update Replica Sets.
  * When live upgrading Kubelet to 1.2 without draining the pods running on the node,

* etcd3: pass SelectionPredicate instead of Filter to storage layer ([#31190](https://github.com/kubernetes/kubernetes/pull/31190), [@hongchaodeng](https://github.com/hongchaodeng))
* etcd3: make gets for previous value in watch serialize-able ([#34089](https://github.com/kubernetes/kubernetes/pull/34089), [@wojtek-t](https://github.com/wojtek-t))

## Changelog since v1.15.3

### Other notable changes

* Restores compatibility with kubectl client-side validation when structural schemas are present in a CRD which sets spec.preserveUnknownFields=true ([#82666](https://github.com/kubernetes/kubernetes/pull/82666), [@liggitt](https://github.com/liggitt))

- Fixed file permission issues that happened during update of Secret/ConfigMap/projected volume when fsGroup is used. The problem caused a race condition where application gets intermittent permission denied error when reading files that were just updated, before the correct permissions were applied. ([#114728](https://github.com/kubernetes/kubernetes/pull/114728), [@furkatgofurov7](https://github.com/furkatgofurov7)) [SIG...

- Fixes a race condition in the iptables mode of kube-proxy in 1.27 and later
  that could result in some updates getting lost (e.g., when a service gets a
  new endpoint, the rules for the new endpoint might not be added until
  much later). ([#122756](https://github.com/kubernetes/kubernetes/pull/122756), [@hakman](https://github.com/hakman)) [SIG Network]