- e2e tests that require SSH may now be used against clusters that have nodes without external IP addresses by setting the environment variable `KUBE_SSH_BASTION` to the `host:port` of a machine that is allowed to SSH to those nodes.  The same private key that the test would use is used for the bastion host.  The test connects to the bastion and then tunnels another SSH connection to the node. ([#72286](https://github.com/kubernetes/kubernetes/pull/72286),...

### **Cluster Lifecycle**

- Support for passing unknown provider names to the E2E test binaries is deprecated and will be removed in a future release. Use `--provider=skeleton` (no ssh access) or `--provider=local` (local cluster with ssh) instead. ([#70141](https://github.com/kubernetes/kubernetes/pull/70141), [@pohly](https://github.com/pohly))

## Major Themes

### SIG API Machinery

* kube-apiserver now uses SSH tunnels for webhooks if the webhook is not directly routable from apiserver's network environment. ([#58644](https://github.com/kubernetes/kubernetes/pull/58644), [@yguo0905](https://github.com/yguo0905))

- The options `--ssh-user` and `--ssh-key` are removed. They only functioned on GCE, and only in-tree. Use the apiserver network proxy instead. ([#102297](https://github.com/kubernetes/kubernetes/pull/102297), [@deads2k](https://github.com/deads2k))

- Fixed bug in error messaging for basic-auth and ssh secret validations. ([#106179](https://github.com/kubernetes/kubernetes/pull/106179), [@vivek-koppuru](https://github.com/vivek-koppuru))

* Fix race causing apiserver crashes during etcd healthchecking ([#60069](https://github.com/kubernetes/kubernetes/pull/60069), [@wojtek-t](https://github.com/wojtek-t))
* Increase allowed lag for ssh key sync loop in tunneler to allow for one failure ([#60068](https://github.com/kubernetes/kubernetes/pull/60068), [@wojtek-t](https://github.com/wojtek-t))