features related to resource management (resource request/limit, quota, limitrange) are available for local ephemeral storage. This local ephemeral storage represents the storage for root file system, which will be consumed by containers' writable layer and logs. Some volumes such as emptyDir might also consume this storage. ([#60159](https://github.com/kubernetes/kubernetes/pull/60159), [@jingxu97](https://github.com/jingxu97))

* VolumeScheduling and LocalPersistentVolume features are...

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.

### SIG API Machinery

[SIG API Machinery][] is responsible for all aspects of the API server: API registration and discovery, generic API CRUD semantics, admission control, encoding/decoding, conversion, defaulting, persistence layer (etcd), OpenAPI, third-party resources, garbage collection, and client libraries.

[beta] User-provided apiservers can be aggregated (served along with) the rest of the Kubernetes API. See [Extending the Kubernetes API with the aggregation layer](https://kubernetes.io/docs/concepts/api-extension/apiserver-aggregation/), [Configure the aggregation layer](https://kubernetes.io/docs/tasks/access-kubernetes-api/configure-aggregation-layer/), and [Setup an extension API server](https://kubernetes.io/docs/tasks/access-kubernetes-api/setup-extension-api-server/).

* [alpha] Adding...

* Provide flags to use etcd3 backed storage ([#24455](https://github.com/kubernetes/kubernetes/pull/24455), [@hongchaodeng](https://github.com/hongchaodeng))

### Other notable changes

* Fix hyperkube's layer caching, and remove --make-symlinks at build time ([#25693](https://github.com/kubernetes/kubernetes/pull/25693), [@luxas](https://github.com/luxas))

the time specified by `--legacy-service-account-token-clean-up-period` (defaulting to one year), **and** are referenced from the `.secrets` list of a ServiceAccount object, **and**  are not referenced from pods. This label causes the authentication layer to reject use of the credentials. After being labeled as invalid, if the time specified by `--legacy-service-account-token-clean-up-period` (defaulting to one year) passes without the credential being used, the secret is automatically deleted. Secrets...

    - [Certificates API](#certificates-api)
    - [Cluster Autoscaler](#cluster-autoscaler)
    - [Deployment](#deployment)
    - [Federation](#federation)
    - [Internal Storage Layer](#internal-storage-layer)
    - [Node Components](#node-components)
    - [kubectl](#kubectl)
    - [RBAC](#rbac)
    - [Scheduling](#scheduling)
    - [Service](#service)
    - [StatefulSet](#statefulset)

* etcd3: dereference the UID pointer for a readable error message. ([#33349](https://github.com/kubernetes/kubernetes/pull/33349), [@madhusudancs](https://github.com/madhusudancs))
* etcd3: pass SelectionPredicate instead of Filter to storage layer ([#31190](https://github.com/kubernetes/kubernetes/pull/31190), [@hongchaodeng](https://github.com/hongchaodeng))