docs: document kubelet cgroup driver detection from the runtime

Document the KubeletCgroupDriverFromCRI feature gate. Also, add notes of
this feature in parts of the documentation that describe cgroup driver
configuration.

content/en/docs/reference/command-line-tools-reference/feature-gates.md

@@ -125,6 +125,7 @@ For a reference to old feature gates that are removed, please refer to
 | `JobReadyPods` | `true` | Beta | 1.24 | |
 | `KMSv2` | `false` | Alpha | 1.25 | 1.26 |
 | `KMSv2` | `true` | Beta | 1.27 | |
+| `KubeletCgroupDriverFromCRI` | `false` | Alpha | 1.28 | |
 | `KubeletInUserNamespace` | `false` | Alpha | 1.22 | |
 | `KubeletPodResourcesDynamicResources` | `false` | Alpha | 1.27 | |
 | `KubeletPodResourcesGet` | `false` | Alpha | 1.27 | |
@@ -559,6 +560,14 @@ Each feature gate is designed for enabling/disabling a specific feature:
   The Job controller uses Pod finalizers and a field in the Job status to keep
   track of the finished Pods to count towards completion.
 - `KMSv2`: Enables KMS v2 API for encryption at rest. See [Using a KMS Provider for data encryption](/docs/tasks/administer-cluster/kms-provider) for more details.
+- `KubeletCgroupDriverFromCRI`: Enable detection of the kubelet cgroup driver
+  configuration option from the CRI. This feature gate requires the user run a
+  container runtime that supports the `RuntimeConfig` CRI call. If both CRI and
+  Kubelet support this feature, the kubelet will ignore the cgroupDriver
+  (--cgroup-driver) configuration option. If the container runtime doesn't
+  support it, the kubelet will fallback to using its cgroupDriver option.
+  See [Configuring a cgroup driver](/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver)
+  for more details.
 - `KubeletCredentialProviders`: Enable kubelet exec credential providers for
   image pull credentials.
 - `KubeletInUserNamespace`: Enables support for running kubelet in a

content/en/docs/setup/production-environment/container-runtimes.md

@@ -157,6 +157,13 @@ Starting with v1.22 and later, when creating a cluster with kubeadm, if the user
 the `cgroupDriver` field under `KubeletConfiguration`, kubeadm defaults it to `systemd`.
 {{< /note >}}
 
+{{< note >}}
+Starting with v1.28 and later, with KubeletCgroupDriverFromCRI feature gate
+enabled and a container runtime that supports the RuntimeConfig CRI rpc,
+kubelet will automatically detect the cgroup driver from the runtime and the
+cgroupDriver setting in kubelet configuration is ignored.
+{{< /note >}}
+
 If you configure `systemd` as the cgroup driver for the kubelet, you must also
 configure `systemd` as the cgroup driver for the container runtime. Refer to
 the documentation for your container runtime for instructions. For example:
@@ -251,6 +258,12 @@ sudo systemctl restart containerd
 When using kubeadm, manually configure the
 [cgroup driver for kubelet](/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver/#configuring-the-kubelet-cgroup-driver).
 
+{{< note >}}
+Starting with v1.28 and later, kubelet cgroup driver does not need to be
+configured if the KubeletCgroupDriverFromCRI feature gate is enabled and a
+version of containerd that supports the RuntimeConfig CRI rpc is being used.
+{{< /note >}}
+
 #### Overriding the sandbox (pause) image {#override-pause-image-containerd}
 
 In your [containerd config](https://github.com/containerd/containerd/blob/main/docs/cri/config.md) you can overwrite the
@@ -292,6 +305,12 @@ You should also note the changed `conmon_cgroup`, which has to be set to the val
 cgroup driver configuration of the kubelet (usually done via kubeadm) and CRI-O
 in sync.
 
+{{< note >}}
+Starting with v1.28 and later, kubelet cgroup driver does not need to be
+configured if the KubeletCgroupDriverFromCRI feature gate is enabled and a
+version of CRI-O that supports the RuntimeConfig CRI rpc is being used.
+{{< /note >}}
+
 For CRI-O, the CRI socket is `/var/run/crio/crio.sock` by default.
 
 #### Overriding the sandbox (pause) image {#override-pause-image-cri-o}

content/en/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver.md

@@ -38,6 +38,13 @@ In v1.22 and later, if the user does not set the `cgroupDriver` field under `Kub
 kubeadm defaults it to `systemd`.
 {{< /note >}}
 
+{{< note >}}
+In v1.28 and later, with KubeletCgroupDriverFromCRI feature gate
+enabled and a container runtime that supports the RuntimeConfig CRI rpc,
+kubelet will automatically detect the cgroup driver from the runtime and the
+kubelet cgroup driver setting does not need to be manually configured.
+{{< /note >}}
+
 A minimal example of configuring the field explicitly:
 
 ```yaml