EBS support across the board. If a Volume is “stuck” in the attaching state to a node for too long a unschedulable taint will be applied to the node, so a Kubernetes admin can [take manual steps to correct the error](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-attaching-volume.html). Users are encouraged to ensure they are monitoring for the taint, and should consider automatically terminating instances in this state.

In addition, support for NVMe disks has been added to Kubernetes,...

* kubeadm: Fix join preflight check false negative ([#49825](https://github.com/kubernetes/kubernetes/pull/49825), [@erhudy](https://github.com/erhudy))
* route_controller will emit "FailedToCreateRoute" event when fails to create route. ([#49821](https://github.com/kubernetes/kubernetes/pull/49821), [@MrHohn](https://github.com/MrHohn))

- When `--rotate-server-certificates` is enabled, kubelet will no longer request a new certificate on startup if the current certificate on disk is satisfactory. ([#69991](https://github.com/kubernetes/kubernetes/pull/69991), [@agunnerson-ibm](https://github.com/agunnerson-ibm))...

certificates directory as `kubelet-client.key` and `kubelet-client.crt`.  Subsequent certificates created by cert rotation were created in a combined PEM file that was atomically rotated as `kubelet-client-DATE.pem` in that directory, which meant clients relying on the `node.kubeconfig` generated by bootstrapping would never use a rotated cert.  The initial bootstrap certificate is now generated into the cert directory as a PEM file and symlinked to `kubelet-client-current.pem` so that the generated kubeconfig...

- Fixed missing delete events on informer re-lists to ensure all delete events were correctly emitted and using the latest known object state, so that all event handlers and stores always reflect the actual apiserver state as best as possible ([#115620](https://github.com/kubernetes/kubernetes/pull/115620), [@odinuge](https://github.com/odinuge))

  - "routeTableCacheTTLInSeconds"
  ([#86266](https://github.com/kubernetes/kubernetes/pull/86266), [@zqingqing1](https://github.com/zqingqing1)) [SIG Cloud Provider]

* During namespace deletion some controllers create event and log spam because they do not recognize namespace deletion as a terminal state. ([#84123](https://github.com/kubernetes/kubernetes/pull/84123), [@smarterclayton](https://github.com/smarterclayton))...

* client-go: shortens refresh period for token files to 1 minute to ensure auto-rotated projected service account tokens are read frequently enough. ([#72437](https://github.com/kubernetes/kubernetes/pull/72437), [@liggitt](https://github.com/liggitt))

- Ignore context canceled from validate and mutate webhook ([#120155](https://github.com/kubernetes/kubernetes/pull/120155), [@divyasri537](https://github.com/divyasri537)) [SIG API Machinery]

- Kubelets configured to rotate client certificates now publish a `certificate_manager_server_ttl_seconds` gauge metric indicating the remaining seconds until certificate expiration. ([#91148](https://github.com/kubernetes/kubernetes/pull/91148), [@liggitt](https://github.com/liggitt))...