* kubeadm: Add a 'kubeadm config migrate' command to convert old API types to their newer counterparts in the new, supported API types. This is just a client-side tool, it just executes locally without requiring a cluster to be running. You can think about this as an Unix pipe that upgrades config files. ([#64232](https://github.com/kubernetes/kubernetes/pull/64232), [@luxas](https://github.com/luxas))

- Topology Aware Hints now ignores unready endpoints when assigning hints. ([#106510](https://github.com/kubernetes/kubernetes/pull/106510), [@robscott](https://github.com/robscott))

- The `TopologyAwareHints` feature gate is now enabled by default. This will allow users to opt-in to Topology Aware Hints by setting the `service.kubernetes.io/topology-aware-hints` on a Service. This will not affect any Services without that annotation...

  Jobs that are tracked using this mechanism get the annotation `batch.kubernetes.io/job-tracking`. This is a temporary measure. Two releases after this feature graduates to beta, the annotation won't be added to Jobs anymore....

**Note**: This only impacts the cluster if the ServiceAccount admission plugin is used (most cluster should have this on by default as recommended in https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#serviceaccount), the `kubernetes.io/enforce-mountable-secrets` annotation is used by a service account (this annotation is not added by default), and Pods are using ephemeral containers.

## Urgent Upgrade Notes

### (No, really, you MUST read this before you upgrade)

#### Cluster Lifecycle

## Urgent Upgrade Notes

### (No, really, you MUST read this before you upgrade)

 - A bug was fixed in kubelet where exec probe timeouts were not respected. Ensure that pods relying on this behavior are updated to correctly handle probe timeouts.
  

  In Linux containers, this means setting the FQDN in the hostname field of the 
  kernel (the nodename field of struct utsname).  In Windows containers, this
  means setting the this means setting the registry value of hostname for the registry key HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters to FQDN. 

      * In 1.3, an init container is specified with this annotation key on the pod or pod template: `pods.alpha.kubernetes.io/init-containers`.
      * In 1.4, either that key or this key: `pods.beta.kubernetes.io/init-containers`,can be used.
    * When you GET an object, you will see both annotation keys with the same values.
      You can safely roll back from 1.4 to 1.3, and things with init-containers

  * You can find out what taints you have in place on a node while you are still running Kubernetes 1.5 by doing `kubectl describe node <node name>`; the `Taints` section will show the taints you have in place. To see the taints that were created under 1.5 when you are running 1.6, do `kubectl get node <node name> -o yaml` and look for the "Annotation" section with the annotation key `scheduler....