docs: add feature gate and version-specific behavior table

Author: ndbaker1

nodeadm/doc/api-concepts.md

@@ -18,4 +18,18 @@ There are three levels of stability and support:
 
 ### Stable
 - Example: `v5`.
-- Support for a stable API will align with the support of a major version of Amazon Linux.
+- Support for a stable API will align with the support of a major version of Amazon Linux.
+
+## Feature Gates
+
+|Name|Default|Since|Until|
+|---|---|---|---|
+|`InstanceIdNodeName`|`false`|-|-|
+
+## Behaviorial Boundaries
+
+|Description|Since|Until|
+|---|---|---|
+|Apply the `nvidia.com/gpu.present=true` node label on startup if NVIDIA devices are detected on the instance|1.35|-|
+|Enable CDI in the default containerd configuration|1.32|-|
+|Write user-provided kubelet config as a kubelet drop-in configuration file|1.29|-|

nodeadm/internal/kubelet/config.go

@@ -336,10 +336,13 @@ func (k *kubelet) GenerateKubeletConfig(cfg *api.NodeConfig) (*kubeletConfig, er
 	kubeletConfig.withCloudProvider(cfg, k.flags)
 	kubeletConfig.withDefaultReservedResources(cfg, k.resources)
 	kubeletConfig.withImageServiceEndpoint(cfg, k.resources)
-	kubeletConfig.withNodeLabels(k.flags, map[string]LabelValueFunc{
+
+	nodeLabelFuncs := map[string]LabelValueFunc{}
+	if semver.Compare(cfg.Status.KubeletVersion, "v1.35.0") >= 0 {
 		// see: https://github.com/NVIDIA/gpu-operator/commit/e25291b86cf4542ac62d8635cda4bd653c4face3
-		"nvidia.com/gpu.present": getNvidiaGPULabel,
-	})
+		nodeLabelFuncs["nvidia.com/gpu.present"] = getNvidiaGPULabel
+	}
+	kubeletConfig.withNodeLabels(k.flags, nodeLabelFuncs)
 
 	return &kubeletConfig, nil
 }

nodeadm/test/e2e/cases/nvidia-gpu-labels/run.sh

@@ -7,7 +7,7 @@ set -o pipefail
 source /helpers.sh
 
 mock::aws
-mock::kubelet 1.32.0
+mock::kubelet 1.35.0
 wait::dbus-ready
 
 nodeadm init --skip run --config-source file://config.yaml
@@ -22,3 +22,12 @@ nodeadm init --skip run --config-source file://config.yaml
 
 assert::file-contains /etc/eks/kubelet/environment '--node-labels=nvidia.com/gpu.present=true'
 assert::file-contains /etc/eks/kubelet/environment '--node-labels=foo=bar'
+
+# the label is only applied start from Kubernetes 1.35+
+
+mock::kubelet 1.34.0
+
+nodeadm init --skip run --config-source file://config.yaml
+
+assert::file-not-contains /etc/eks/kubelet/environment '--node-labels=nvidia.com/gpu.present=true'
+assert::file-contains /etc/eks/kubelet/environment '--node-labels=foo=bar'