- Alpha support for field selectors on custom resources has been added. With the `CustomResourceFieldSelectors` feature gate enabled, the CustomResourceDefinition API now allows specifying `selectableFields`. Listing a field there enables filtering custom resources for that CustomResourceDefinition in list or watch requests. ([#122717](https://github.com/kubernetes/kubernetes/pull/122717), [@jpbetz](https://github.com/jpbetz))

Kubelet supports 100 pods per node with 4x reduced system overhead.
  * <strong>Simplified application deployment and management. </strong>
     * Dynamic Configuration (ConfigMap API in the core API group) enables application
configuration to be stored as a Kubernetes API object and pulled dynamically on
container startup, as an alternative to baking in command-line flags when a
container is built.

* [alpha] Adding admissionregistration API group which enables dynamic registration of initializers and external admission webhooks. ([#46294](https://github.com/kubernetes/kubernetes/pull/46294), [@caesarxuchao](https://github.com/caesarxuchao))


### **Application Deployment**

Pod Priority and Preemption in Kubernetes ([#564](https://github.com/kubernetes/enhancements/issues/564))

- Pod priority and preemption enables Kubernetes scheduler to schedule more important Pods first and when cluster is out of resources, it removes less important pods to create room for more important ones. The importance is specified by priority.

- 'Container `preStop` and `postStart` lifecycle handlers using `httpGet` now
  honor the specified `scheme` and `headers` fields. This enables setting custom
  headers and changing the scheme to `HTTPS`, consistent with container
  startup/readiness/liveness probe capabilities. Lifecycle handlers configured