* TCP is stateful, so we cannot really just pass state over to the other process.
  If we operated at L3 we could just start processing packets in the new Ztunnel.
* We do not operate at L7, so we cannot signal to the application, in any way, that it should reconnect (to the new Ztunnel).

Realistically, that means the best we can do is:

Ztunnel was not designed to be a feature-rich data plane.
Quite the opposite - an *aggressively* small feature set is the key feature that makes ztunnel viable.
It very intentionally does not offer L7 (HTTP) functionality, for instance, which would likely violate some of the goals above, without contributing to them.
Instead, the rich functionality that service mesh is traditionally associated with is deferred to the waypoints.

Extensions API group): Kubernetes can schedule a service (such as a logging
agent) that runs one, and only one, pod per node.
     * TLS and L7 support (Ingress API (Beta) in the Extensions API group): Kubernetes
is now easier to integrate into custom networking environments by supporting
TLS for secure communication and L7 http-based traffic routing.
     * Graceful Node Shutdown (aka drain) - The new “kubectl drain” command gracefully

* Updating:
  * Retry Pod/RC updates in kubectl rolling-update.
  * Stop 'kubectl drain' deleting pods with local storage.
  * Add `kubectl rollout status`
* Security/Auth
  * L7 LB controller and disk attach controllers run on master, so nodes do not need those privileges.
  * Setting TLS1.2 minimum
  * `kubectl create secret tls` command
  * Webhook Token Authenticator

`CVE-2023-44487` and `CVE-2023-39325` for the API server when the client is unauthenticated. The mitigation may be disabled by setting the `UnauthenticatedHTTP2DOSMitigation` feature gate to `false` (it is enabled by default). An API server fronted by an L7 load balancer that already mitigates these http/2 attacks may choose to disable the kube-apiserver mitigation to avoid disrupting load balancer -> kube-apiserver connections if http/2 requests from multiple clients share the same backend connection....

    Federation control system then creates and maintains a single
    global virtual IP to load balance incoming HTTP(S) traffic across
    some or all the registered clusters, across all regions. Google's
    GCE L7 LoadBalancer is the first supported implementation, and
	is available in this release.
	([docs](http://kubernetes.io/docs/user-guide/federation/federated-ingress.md))

* Allow user to scale l7 default backend deployment ([#62685](https://github.com/kubernetes/kubernetes/pull/62685), [@freehan](https://github.com/freehan))

CVE-2023-44487 and CVE-2023-39325 for the API server when the client is unauthenticated. The mitigation may be enabled by setting the `UnauthenticatedHTTP2DOSMitigation` feature gate to `true` (it is disabled by default). An API server fronted by an L7 load balancer that already mitigates these http/2 attacks may choose not to enable the kube-apiserver mitigation to avoid disrupting load balancer → kube-apiserver connections if http/2 requests from multiple clients share the same backend connection....

CVE-2023-44487 and CVE-2023-39325 for the API server when the client is unauthenticated. The mitigation may be enabled by setting the `UnauthenticatedHTTP2DOSMitigation` feature gate to `true` (it is disabled by default). An API server fronted by an L7 load balancer that already mitigates these http/2 attacks may choose not to enable the kube-apiserver mitigation to avoid disrupting load balancer → kube-apiserver connections if http/2 requests from multiple clients share the same backend connection....

CVE-2023-44487 and CVE-2023-39325 for the API server when the client is unauthenticated. The mitigation may be enabled by setting the `UnauthenticatedHTTP2DOSMitigation` feature gate to `true` (it is disabled by default). An API server fronted by an L7 load balancer that already mitigates these http/2 attacks may choose not to enable the kube-apiserver mitigation to avoid disrupting load balancer → kube-apiserver connections if http/2 requests from multiple clients share the same backend connection....