- `kubeadm`: Started using a named port `probe-port` for all probes in the static pod manifests generated by `kubeadm` for the `kube-apiserver`, `kube-controller-manager`, `kube-scheduler`, and related components. If probe port values were previously patched using `kubeadm` patches, the corresponding named port under the container’s `ports` field must now also be patched. ([#1327...

    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.
    * Remove metadata agent config maps in favor of command line flags.
    * Update the metadata agent's liveness probe to a new /healthz handler.
    * Logging Agent Improvements
    * Bump logging agent version to 0.2-1.5.33-1-k8s-1.
    * Appropriately set log severity for k8s_container.

- Single static pod files and pod files from http endpoints cannot be larger than 10 MB. HTTP probe payloads are now truncated to 10KB. ([#82669](https://github.com/kubernetes/kubernetes/pull/82669), [@rphillips](https://github.com/rphillips))

  - Health check (liveness & readiness) probes using an HTTPGetAction will no longer follow redirects to different hostnames from the original probe request. Instead, these non-local redirects will be treated as a Success (the documented behavior). In this case an event with reason "ProbeWarning" will be generated, indicating that the redirect was ignored. If you were previously relying on the...

- Limit the body length of exec readiness/liveness probes. remote CRIs and Docker shim read a max of 16MB output of which the exec probe itself inspects 10kb. ([#82514](https://github.com/kubernetes/kubernetes/pull/82514), [@dims](https://github.com/dims))

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

    * Bump metadata agent version to 0.2-0.0.21-1.
    * Expand the metadata agent's access to all API groups.
    * Remove metadata agent config maps in favor of command line flags.
    * Update the metadata agent's liveness probe to a new /healthz handler.
    * Logging Agent Improvements
    * Bump logging agent version to 0.2-1.5.33-1-k8s-1.
    * Appropriately set log severity for k8s_container.

- Kubeadm: make sure the etcd static pod startup probe uses /health?serializable=false while the liveness probe uses /health?serializable=true&exclude=NOSPACE. The NOSPACE exclusion would allow administrators to address space issues one member at a time. ([#110744](https://github.com/kubernetes/kubernetes/pull/110744), [@neolit1...

- kubeadm: switched the kube-scheduler static Pod to use the endpoints `/livez` (for startup and liveness probes) and `/readyz` (for the readiness probe). Previously, `/healthz` was used for all probes, which is deprecated behavior in the scope of this component. ([#126945](https://github.com/kubernetes/kubernetes/pull/126945), [@liangyuanpeng](https://github.com/liangyuanpeng)) [SIG Cluster Lifecycle]...

- Pod status updates faster when reacting on probe results. The first readiness probe will be called faster when startup probes succeeded, which will make Pod status as ready faster. ([#98376](https://github.com/kubernetes/kubernetes/pull/98376), [@matthyx](https://github.com/matthyx))