feat(cluster): Add control plane scaling configuration support (#240)

Issue #, if available: [community#2972](aws-controllers-k8s/community#2972)

Description of changes:
- Un-ignore CreateClusterInput/Output.ControlPlaneScalingConfig in generator.yaml and regenerate the API types, SDK, CRDs, and deepcopy code
- Add a custom update path (`updateControlPlaneScalingConfig`) that calls `UpdateClusterConfig` and requeues on `ResourceInUseException`, plus delta comparison for `Spec.ControlPlaneScalingConfig.Tier`
- Handle the AWS-populated default tier: `customPreCompare` copies the latest value onto desired when unset, and Tier is late-initialized so the server-assigned default is reflected back into Spec without a perpetual diff
- Add an e2e test that creates a cluster with tier "standard" and updates it to "tier-xl", verifying the change via `DescribeCluster`

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Author: gobos12

apis/v1alpha1/ack-generate-metadata.yaml

@@ -1,13 +1,13 @@
 ack_generate_info:
-  build_date: "2026-08-04T17:39:48Z"
+  build_date: "2026-08-07T17:49:33Z"
   build_hash: db232581a560896c2dc461a244f96d5bf3191ec6
-  go_version: go1.26.5
+  go_version: go1.26.0
   version: v0.62.0
-api_directory_checksum: 621c93f1d724aa33a1f78e47c25d6eb2ddf629e1
+api_directory_checksum: 2b5287d0ef597d7039841a4cb7f7ffcb11e36bf8
 api_version: v1alpha1
 aws_sdk_go_version: v1.41.2
 generator_config_info:
-  file_checksum: db46c605be19c5941469cfff7e4d18f4af00754f
+  file_checksum: 5a8408f5d7d6b65570ded0a2505a15c2d89d2ab1
   original_file_name: generator.yaml
 last_modification:
   reason: API generation

apis/v1alpha1/cluster.go

@@ -197,6 +197,8 @@ resources:
         late_initialize: {}
         compare:
           pre_delete_include: true
+      ControlPlaneScalingConfig.Tier:
+        late_initialize: {}
     exceptions:
       errors:
         404:
@@ -635,5 +637,3 @@ ignore:
   - CreateCapabilityInput.ClientRequestToken
   - CreateAddonInput.NamespaceConfig
   - CreateAddonOutput.Addon.NamespaceConfig
-  - CreateClusterInput.ControlPlaneScalingConfig
-  - CreateClusterOutput.Cluster.ControlPlaneScalingConfig

apis/v1alpha1/generator.yaml

@@ -102,6 +102,14 @@ spec:
                   nodeRoleARN:
                     type: string
                 type: object
+              controlPlaneScalingConfig:
+                description: |-
+                  The control plane scaling tier configuration. For more information, see EKS
+                  Provisioned Control Plane in the Amazon EKS User Guide.
+                properties:
+                  tier:
+                    type: string
+                type: object
               deletionProtection:
                 description: |-
                   Indicates whether to enable deletion protection for the cluster. When enabled,

apis/v1alpha1/types.go

@@ -197,6 +197,8 @@ resources:
         late_initialize: {}
         compare:
           pre_delete_include: true
+      ControlPlaneScalingConfig.Tier:
+        late_initialize: {}
     exceptions:
       errors:
         404:
@@ -635,5 +637,3 @@ ignore:
   - CreateCapabilityInput.ClientRequestToken
   - CreateAddonInput.NamespaceConfig
   - CreateAddonOutput.Addon.NamespaceConfig
-  - CreateClusterInput.ControlPlaneScalingConfig
-  - CreateClusterOutput.Cluster.ControlPlaneScalingConfig

apis/v1alpha1/zz_generated.deepcopy.go

@@ -102,6 +102,14 @@ spec:
                   nodeRoleARN:
                     type: string
                 type: object
+              controlPlaneScalingConfig:
+                description: |-
+                  The control plane scaling tier configuration. For more information, see EKS
+                  Provisioned Control Plane in the Amazon EKS User Guide.
+                properties:
+                  tier:
+                    type: string
+                type: object
               deletionProtection:
                 description: |-
                   Indicates whether to enable deletion protection for the cluster. When enabled,

config/crd/bases/eks.services.k8s.aws_clusters.yaml

@@ -191,6 +191,9 @@ func customPreCompare(
 	if a.ko.Spec.UpgradePolicy == nil && b.ko.Spec.UpgradePolicy != nil {
 		a.ko.Spec.UpgradePolicy = b.ko.Spec.UpgradePolicy.DeepCopy()
 	}
+	if a.ko.Spec.ControlPlaneScalingConfig == nil && b.ko.Spec.ControlPlaneScalingConfig != nil {
+		a.ko.Spec.ControlPlaneScalingConfig = b.ko.Spec.ControlPlaneScalingConfig.DeepCopy()
+	}
 }
 
 func (rm *resourceManager) customUpdate(
@@ -416,6 +419,21 @@ func (rm *resourceManager) customUpdate(
 		return returnClusterUpdating(updatedRes)
 	}
 
+	// Handle controlPlaneScalingConfig updates
+	if delta.DifferentAt("Spec.ControlPlaneScalingConfig") {
+		if err := rm.updateControlPlaneScalingConfig(ctx, desired); err != nil {
+			awsErr, ok := extractAWSError(err)
+
+			// Check to see if we've raced an async update call and need to requeue
+			if ok && awsErr.Code == "ResourceInUseException" {
+				return nil, requeueAfterAsyncUpdate()
+			}
+
+			return nil, err
+		}
+		return returnClusterUpdating(updatedRes)
+	}
+
 	// Handle deletionProtection updates
 	if delta.DifferentAt("Spec.DeletionProtection") {
 		if err := rm.updateDeletionProtection(ctx, desired); err != nil {
@@ -764,6 +782,33 @@ func (rm *resourceManager) updateZonalShiftConfig(
 	return nil
 }
 
+// updateControlPlaneScalingConfig updates the control plane scaling tier of
+// the cluster.
+func (rm *resourceManager) updateControlPlaneScalingConfig(
+	ctx context.Context,
+	r *resource,
+) (err error) {
+	rlog := ackrtlog.FromContext(ctx)
+	exit := rlog.Trace("rm.updateControlPlaneScalingConfig")
+	defer exit(err)
+
+	input := &svcsdk.UpdateClusterConfigInput{
+		Name:                      r.ko.Spec.Name,
+		ControlPlaneScalingConfig: &svcsdktypes.ControlPlaneScalingConfig{},
+	}
+	if r.ko.Spec.ControlPlaneScalingConfig.Tier != nil {
+		input.ControlPlaneScalingConfig.Tier = svcsdktypes.ProvisionedControlPlaneTier(*r.ko.Spec.ControlPlaneScalingConfig.Tier)
+	}
+
+	_, err = rm.sdkapi.UpdateClusterConfig(ctx, input)
+	rm.metrics.RecordAPICall("UPDATE", "UpdateClusterConfig", err)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (rm *resourceManager) updateDeletionProtection(
 	ctx context.Context,
 	r *resource,