- Added support for projected volume in describe function  ([#70158](https://github.com/kubernetes/kubernetes/pull/70158), [@WanLinghao](https://github.com/WanLinghao))
- kubeadm now automatically creates a new stacked etcd member when joining a new control plane node (does not applies to external etcd) ([#69486](https://github.com/kubernetes/kubernetes/pull/69486), [@fabriziopandini](https://github.com/fabriziopandini))

from v1beta3 and its management in the kube-system/kubeadm-config ConfigMap. This method of keeping track of what API endpoints exists in the cluster was replaced (in a prior release) by a method to annotate the etcd Pods that `kubeadm` creates in "stacked etcd" clusters. The following CLI sub-phases are deprecated and are now a NO-OP: for `kubeadm join`: "control-plane-join/update-status", for `kubeadm reset`: "update-cluster-status". Unless you are using these phases explicitly, you should not be...

### IPv4/IPv6 run

IPv4/IPv6 dual-stack has been reimplemented for 1.20 to support dual-stack Services, based on user and community feedback. If your cluster has dual-stack enabled, you can create Services which can use IPv4, IPv6, or both, and you can change this setting for existing Services. Details are available in updated [IPv4/IPv6 dual-stack docs](https://docs.k8s.io/concepts/services-networking/dual-stack/), which cover the nuanced array of options.

- [`KT-56835`](https://youtrack.jetbrains.com/issue/KT-56835) Light classes: Underlying fields for delegated properties should be marked as final and `@NotNull`
- [`KT-56840`](https://youtrack.jetbrains.com/issue/KT-56840) Light Classes: Inline classes backed by Java primitives shouldn't be marked with `@NotNull`

- Kube-proxy: on dual-stack mode, if it is not able to get the IP Family of an endpoint, logs it with level InfoV(4) instead of Warning, avoiding flooding the logs for endpoints without addresses ([#88934](https://github.com/kubernetes/kubernetes/pull/88934), [@aojea](https://github.com/aojea)) [SIG Network]

- Users might specify the `kubectl.kubernetes.io/default-container` annotation in a Pod to...

## Changelog since v1.15.0

### Other notable changes

* kubeadm: implement support for concurrent add/remove of stacked etcd members ([#79677](https://github.com/kubernetes/kubernetes/pull/79677), [@neolit123](https://github.com/neolit123))

  // to SingleStack. Services can be "SingleStack" (a single IP family),
  // "PreferDualStack" (two IP families on dual-stack configured clusters or
  // a single IP family on single-stack clusters), or "RequireDualStack"
  // (two IP families on dual-stack configured clusters, otherwise fail). The
  // ipFamilies and clusterIPs fields depend on the value of this field. This

## Known Issues

* If you need to downgrade from 1.10 to 1.9.x, downgrade to v1.9.6 to ensure PV and PVC objects can be deleted properly.

* Ensure cloudprovider.InstanceNotFound is reported when the VM is not found on Azure ([#61531](https://github.com/kubernetes/kubernetes/pull/61531), [@feiskyer](https://github.com/feiskyer))
* On AWS kubelet returns an error when started under conditions that do not allow it to work (AWS has not yet tagged the instance). ([#60125](https://github.com/kubernetes/kubernetes/pull/60125), [@vainu-arto](https://github.com/vainu-arto))