Two alpha features were also added in this release.

The RuntimeClass alpha feature enables a node to surface multiple runtime options to support a variety of workload types.  Examples include native linux containers, and “sandboxed” containers that isolate the container from the host kernel.

* rbd: default image format to v2 instead of deprecated v1 ([#51574](https://github.com/kubernetes/kubernetes/pull/51574), [@dillaman](https://github.com/dillaman))
* Surface reasonable error when client detects connection closed. ([#51381](https://github.com/kubernetes/kubernetes/pull/51381), [@mengqiy](https://github.com/mengqiy))

* Add a way to pass extra arguments to etcd. ([#63961](https://github.com/kubernetes/kubernetes/pull/63961), [@mborsz](https://github.com/mborsz))
* kubeadm: surface external etcd preflight validation errors ([#60585](https://github.com/kubernetes/kubernetes/pull/60585), [@alexbrand](https://github.com/alexbrand))



# v1.10.3

- [`KT-56608`](https://youtrack.jetbrains.com/issue/KT-56608) WASI Preview1 version of Kotlin/Wasm stdlib
- [`KT-55765`](https://youtrack.jetbrains.com/issue/KT-55765) Review and stabilize stdlib surface available in K/N
- [`KT-55297`](https://youtrack.jetbrains.com/issue/KT-55297) kotlin-stdlib should declare constraints on kotlin-stdlib-jdk8 and kotlin-stdlib-jdk7

SIG Storage made a lot of progress in the 1.18 release.
In particular, the following storage features are moving to GA in Kubernetes 1.18:
- Raw Block Support: Allow volumes to be surfaced as block devices inside containers instead of just mounted filesystems.
- Volume Cloning: Duplicate a PersistentVolumeClaim and underlying storage volume using the Kubernetes API via CSI.

* Add generators for `apps/v1` deployments. ([#61288](https://github.com/kubernetes/kubernetes/pull/61288), [@ayushpateria](https://github.com/ayushpateria))
* kubeadm: surface external etcd preflight validation errors ([#60585](https://github.com/kubernetes/kubernetes/pull/60585), [@alexbrand](https://github.com/alexbrand))

  - The issuer of the certificate is unknown (x509.UnknownAuthorityError)
  - The requested name does not match the set of authorized names (x509.HostnameError)

  - The issuer of the certificate is unknown (x509.UnknownAuthorityError)
  - The requested name does not match the set of authorized names (x509.HostnameError)

  - The issuer of the certificate is unknown (x509.UnknownAuthorityError)
  - The requested name does not match the set of authorized names (x509.HostnameError)

As a consequence of this change the Kubelet now correctly takes into account the resources of running and terminating pods when deciding to accept new pods, since terminating pods are still holding on to those resources. This stricter handling may surface to end users as pod rejections when creating pods that are scheduled to mostly full nodes that have other terminating pods holding the resources the new pods need. The most likely error would be a pod set to `Failed` phase with reason set to `OutOfCpu`...