- Kubeadm: remove the deprecated `--csr-only` and `--csr-dir` flags...

an element of a structured variable.
Variables of interface type also have a distinct <i>dynamic type</i>,
which is the (non-interface) type of the value assigned to the variable at run time
(unless the value is the predeclared identifier <code>nil</code>,
which has no type).
The dynamic type may vary during execution but values stored in interface
variables are always <a href="#Assignability">assignable</a>

- Fixed tracking of terminating Pods in the Job status. The field was not updated unless there were other changes to apply. ([#121342](https://github.com/kubernetes/kubernetes/pull/121342), [@dejanzele](https://github.com/dejanzele))

* Admission control support for versioned configuration files ([#39109](https://github.com/kubern...

- Enabled use of pods with volumes and user namespaces....

- kube-controller-manager and cloud-controller-manager now hold generated serving certificates in-memory unless a writeable location is specified with --cert-dir ([#69884](https://github.com/kubernetes/kubernetes/pull/69884), [@liggitt](https://github.com/liggitt))

- EndpointSlice controller is now less likely to emit FailedToUpdateEndpointSlices events. ([#100113](https://github.com/kubernetes/kubernetes/pull/100113), [@robscott](https://github.com/robscott)) [SIG Apps and Network]

Some upgrade methods might upgrade etcd from 3.0 to 3.1 automatically when you upgrade from Kubernetes 1.8, unless you specify otherwise. Because [etcd does not support downgrading](https://coreos.com/etcd/docs/latest/upgrades/upgrade_3_1.html), you'll need to either remain on etcd 3.1 or restore from a backup if you want to downgrade back to Kubernetes 1.8.

 - Kubeadm: during "init" an empty cgroupDriver value in the KubeletConfiguration is now always set to "systemd" unless the user is explicit about it. This requires existing machine setups to configure the container runtime to use the "systemd" driver. Documentation on this topic can be found here: https://kubernetes.io/docs/setup/production-environment/container-runtimes/....

- InPlacePodVerticalScaling: Memory limits cannot be decreased unless the memory resize restart policy is set to `RestartContainer`. Container resizePolicy is no longer mutable. ([#130183](https://github.com/kubernetes/kubernetes/pull/130183), [@tallclair](https://github.com/tallclair)) [SIG Apps and Node]