New alpha features include:
* Online volume resizing will increase the filesystem size of a resized volume without requiring a Pod restart.
* AWS EBS and GCE PD volumes support increased limits on the maximum number of attached volumes per node.
* Subpath volume directories can be created using DownwardAPI environment variables.

that allows it to track container images and the list of authentication information that leads to their successful pulls. This data is persisted across reboots of the host and restarts of the kubelet.
  
  The kubelet ensures any image requiring credential verification is always pulled if authentication information from an image pull is not yet present, thus enforcing authentication / re-authentication. This means an image pull might be attempted even in cases where a pod requests the `IfNotPresent`...

list of group aliases (e.g. "all") that every resource belongs to. ([#43338](https://github.com/kubernetes/kubernetes/pull/43338), [@fabianofranz](https://github.com/fabianofranz))

* `--service-account-lookup` now defaults to true, requiring the Secret API object containing the token to exist in order for a service account token to be valid. This enables service account tokens to be revoked by deleting the Secret object containing the token. ([#44071](https://github.com/kubernetes/k...

Kube-proxy's IPVS proxy mode no longer sets the net.ipv4.conf.all.route_localnet sysctl parameter. Nodes upgrading will have net.ipv4.conf.all.route_localnet set to 1 but new nodes will inherit the system default (usually 0). If you relied on any behavior requiring net.ipv4.conf.all.route_localnet, you must set ensure it is enabled as kube-proxy will no longer set it automatically. This change helps to further mitigate CVE-2020-8558. ([#92938](https://github.com/kubernetes/kubernetes/pull/92938), [@lbernai...

  [overwrite of manual edits to GCP Health Checks](https://github.com/kubernetes/ingress/issues/842)
  managed by the GLBC Ingress Controller. This can cause the health checks to start failing,
  requiring you to reapply the manual edits.
  * This issue does not affect clusters that were already running Kubernetes v1.6.4 or higher.
  * This issue does not affect Health Checks that were left in the configuration

- Removed an inaccurate statement about requiring ports when the Pod spec `hostNetwork` field was set. ([#130994](https://github.com/kubernetes/kubernetes/pull/130994), [@BenTheElder](https://github.com/BenTheElder)) [SIG Network and Node]

feature to support referencing counter sets across ResourceSlices within the same resource pool. Devices from incomplete pools were no longer considered for allocation. This change introduced backwards-incompatible updates to the alpha feature, requiring any ResourceSlices using it to be removed before upgrading or downgrading between v1.34 and v1.35. ([#134189](https://github.com/kubernetes/kubernetes/pull/134189), [@mortent](https://github.com/mortent)) [SIG API Machinery, Node, Scheduling and...

* [alpha] Improve Flex volume deployment

  * Flex volume driver deployment is simplified in the following ways:

    * New driver files can now be automatically discovered and initialized without requiring a kubelet or controller-manager restart.

    * A sample DaemonSet to deploy Flexvolume drivers is now available.

* [prototype] Volume snapshots

the KUBECONFIG file.) This way, users can now  set a Google Service Account JSON key in the  GOOGLE_APPLICATION_CREDENTIALS environment variable, craft a kubeconfig file with GKE master IP+CA cert, and authenticate to GKE in headless mode without requiring gcloud CLI. ([#58141](https://github.com/kubernetes/kubernetes/pull/58141), [@ahmetb](https://github.com/ahmetb))

* kubectl port-forward no longer supports the deprecated -p <pod-name> flag; the flag itself is unnecessary and should...

- Improved the efficiency of NodeAdded QueueingHint by registering UpdateNodeTaint event for plugins that have NodeAdded event but don't have UpdateNodeTaint event. This ensures better requeuing efficiency and prevents Pods from being stuck in the unschedulable pod pool.
   ([#122292](https://github.com/kubernetes/kubernetes/pull/122292), [@sanposhiho](https://github.com/sanposhiho))