Add validation for enabling with node-termination-handler

Signed-off-by: Ciprian Hacman <[email protected]>

Author: hakman

pkg/apis/kops/validation/validation.go

@@ -1898,6 +1898,9 @@ func validateMetricsServer(cluster *kops.Cluster, spec *kops.MetricsServerConfig
 }
 
 func validateNodeTerminationHandler(cluster *kops.Cluster, spec *kops.NodeTerminationHandlerSpec, fldPath *field.Path) (allErrs field.ErrorList) {
+	if (spec.Enabled == nil || *spec.Enabled == true) && cluster.Spec.Karpenter != nil && cluster.Spec.Karpenter.Enabled {
+		allErrs = append(allErrs, field.Forbidden(fldPath, "nodeTerminationHandler cannot be used in conjunction with Karpenter"))
+	}
 	if spec.IsQueueMode() {
 		if spec.EnableSpotInterruptionDraining != nil && !*spec.EnableSpotInterruptionDraining {
 			allErrs = append(allErrs, field.Forbidden(fldPath.Child("enableSpotInterruptionDraining"), "spot interruption draining cannot be disabled in Queue Processor mode"))

pkg/model/components/nodeterminationhandler.go

@@ -35,18 +35,17 @@ func (b *NodeTerminationHandlerOptionsBuilder) BuildOptions(o *kops.Cluster) err
 	if clusterSpec.CloudProvider.AWS == nil {
 		return nil
 	}
+	if clusterSpec.Karpenter != nil && clusterSpec.Karpenter.Enabled {
+		// Karpenter manages its own NTH, so we disable the NTH addon.
+		// https://karpenter.sh/docs/troubleshooting/#aws-node-termination-handler-nth-interactions
+		return nil
+	}
 	if clusterSpec.CloudProvider.AWS.NodeTerminationHandler == nil {
 		clusterSpec.CloudProvider.AWS.NodeTerminationHandler = &kops.NodeTerminationHandlerSpec{}
 	}
 	nth := clusterSpec.CloudProvider.AWS.NodeTerminationHandler
 	if nth.Enabled == nil {
-		if clusterSpec.Karpenter != nil && clusterSpec.Karpenter.Enabled {
-			// Karpenter manages its own NTH, so we disable the NTH addon.
-			// https://karpenter.sh/docs/troubleshooting/#aws-node-termination-handler-nth-interactions
-			nth.Enabled = fi.PtrTo(false)
-		} else {
-			nth.Enabled = fi.PtrTo(true)
-		}
+		nth.Enabled = fi.PtrTo(true)
 	}
 	if !fi.ValueOf(nth.Enabled) {
 		return nil

tests/integration/update_cluster/karpenter/data/aws_s3_object_cluster-completed.spec_content

@@ -184,8 +184,6 @@ spec:
   networkCIDR: 172.20.0.0/16
   networking:
     cni: {}
-  nodeTerminationHandler:
-    enabled: false
   nonMasqueradeCIDR: 100.64.0.0/10
   podCIDR: 100.96.0.0/11
   secretStore: memfs://clusters.example.com/minimal.example.com/secrets