<p>
In its most basic form an interface specifies a (possibly empty) list of methods.
The type set defined by such an interface is the set of types which implement all of
those methods, and the corresponding <a href="#Method_sets">method set</a> consists
exactly of the methods specified by the interface.
Interfaces whose type sets can be defined entirely by a list of methods are called
<i>basic interfaces.</i>
</p>

<pre>

- `Kubelet` no longer creates certain legacy iptables rules by default.

* Kubernetes now supports up to 5,000 nodes via etcd v3, which is enabled by default.
* [Role-based access control (RBAC)](https://kubernetes.io//docs/admin/authorization/rbac) has graduated to beta, and defines secure default roles for control plane, node, and controller components.
* The [`kubeadm` cluster bootstrap tool](https://kubernetes.io/docs/getting-started-guides/kubeadm/) has graduated to beta. Some highlights:

* CRI now defines mounting behavior. If the host path doesn't exist, the runtime should return an error. If the host path is a symlink, the runtime should follow the symlink and mount the real destination to the container. ([#61460](https://github.com/kubernetes/k...

- The RuntimeClass API has been added. This feature is in alpha, and the RuntimeClass feature gate must be enabled in order to use it. The RuntimeClass API resource defines different classes of runtimes that may be used to run containers in the cluster. Pods can select a RuntimeClass to use via the RuntimeClassName field. ([#67737](https://github.com/kubernetes/kubernetes/pull/67737), [@tallclair](https://github.com/tallclair))...

    Potential impacts:

- When scaling down a ReplicaSet, delete doubled up replicas first, where a "doubled up replica" is defined as one that is on the same node as an active replica belonging to a related ReplicaSet.  ReplicaSets are considered "related" if they have a common controller (typically a Deployment). ([#80004](https://github.com/kubernetes/kubernetes/pull/80004),...

- `kubectl apply  -f <file> --prune -n <namespace>` should prune all resources not defined in the file in the cli specified namespace. ([#85613](https://github.com/kubernetes/kubernetes/pull/85613), [@MartinKaburu](https://github.com/MartinKaburu)) [SIG CLI]

    * Introduce a RuntimeClass v1beta1 API. This new beta API renames `runtimeHandler` to `handler`, makes it a required field,...

- kube-proxy waits for some duration for the node to be defined. ([#77167](https://github.com/kubernetes/kubernetes/pull/77167), [@paulsubrata55](https://github.com/paulsubrata55))