Default to overlay enabled when shoot networking config is nil

pkg/controller/controlplane/valuesprovider.go

@@ -411,7 +411,7 @@ func getCCMChartValues(
 
 func isOverlayEnabled(networking *gardencorev1beta1.Networking) (bool, error) {
 	if networking == nil || networking.ProviderConfig == nil {
-		return false, nil
+		return true, nil
 	}
 
 	obj, err := runtime.Decode(unstructured.UnstructuredJSONScheme, networking.ProviderConfig.Raw)
@@ -429,7 +429,7 @@ func isOverlayEnabled(networking *gardencorev1beta1.Networking) (bool, error) {
 		return false, err
 	}
 	if !ok {
-		return false, nil
+		return true, nil
 	}
 
 	return enabled, nil

pkg/controller/controlplane/valuesprovider_test.go

@@ -497,6 +497,129 @@ var _ = Describe("Valueprovider Reconcile", func() {
 				},
 			}))
 		})
+
+		It("should not configure cloud routes when networking provider config is nil", func(ctx SpecContext) {
+			cp := &extensionsv1alpha1.ControlPlane{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "control-plane",
+					Namespace: ns.Name,
+				},
+				Spec: extensionsv1alpha1.ControlPlaneSpec{
+					Region: "foo",
+					SecretRef: corev1.SecretReference{
+						Name:      "my-infra-creds",
+						Namespace: ns.Name,
+					},
+					DefaultSpec: extensionsv1alpha1.DefaultSpec{
+						Type: ironcore.Type,
+						ProviderConfig: &runtime.RawExtension{
+							Raw: encode(&apisironcore.ControlPlaneConfig{
+								CloudControllerManager: &apisironcore.CloudControllerManagerConfig{
+									FeatureGates: map[string]bool{
+										"CustomResourceValidation": true,
+									},
+								},
+							}),
+						},
+					},
+					InfrastructureProviderStatus: &runtime.RawExtension{
+						Raw: encode(&apisironcore.InfrastructureStatus{
+							NetworkRef: v1alpha1.LocalUIDReference{
+								Name: "my-network",
+								UID:  "1234",
+							},
+						}),
+					},
+				},
+			}
+			providerCloudProfile := &apisironcore.CloudProfileConfig{
+				StorageClasses: apisironcore.StorageClasses{
+					Default: &apisironcore.StorageClass{
+						Name: "foo",
+						Type: "volumeTypeFoo",
+					},
+					Additional: []apisironcore.StorageClass{
+						{
+							Name: "bar",
+							Type: "volumeTypeBar",
+						},
+					},
+				},
+			}
+			providerCloudProfileJson, err := json.Marshal(providerCloudProfile)
+			Expect(err).NotTo(HaveOccurred())
+			cluster := &controller.Cluster{
+				CloudProfile: &gardencorev1beta1.CloudProfile{
+					Spec: gardencorev1beta1.CloudProfileSpec{
+						ProviderConfig: &runtime.RawExtension{
+							Raw: providerCloudProfileJson,
+						},
+					},
+				},
+				Shoot: &gardencorev1beta1.Shoot{
+					ObjectMeta: metav1.ObjectMeta{
+						Namespace: ns.Name,
+						Name:      "my-shoot",
+					},
+					Spec: gardencorev1beta1.ShootSpec{
+						Networking: &gardencorev1beta1.Networking{
+							Pods: ptr.To[string]("10.0.0.0/16"),
+						},
+						Kubernetes: gardencorev1beta1.Kubernetes{
+							Version: "1.26.0",
+							VerticalPodAutoscaler: &gardencorev1beta1.VerticalPodAutoscaler{
+								Enabled: true,
+							},
+						},
+					},
+				},
+			}
+
+			checksums := map[string]string{
+				ironcore.CloudProviderConfigName: "8bafb35ff1ac60275d62e1cbd495aceb511fb354f74a20f7d06ecb48b3a68432",
+			}
+			values, err := vp.GetControlPlaneChartValues(ctx, cp, cluster, fakeSecretsManager, checksums, false)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(values).To(Equal(map[string]interface{}{
+				"global": map[string]interface{}{
+					"genericTokenKubeconfigSecretName": "generic-token-kubeconfig",
+				},
+				"cloud-controller-manager": map[string]interface{}{
+					"enabled":     true,
+					"replicas":    1,
+					"clusterName": ns.Name,
+					"podAnnotations": map[string]interface{}{
+						"checksum/secret-cloud-provider-config": "8bafb35ff1ac60275d62e1cbd495aceb511fb354f74a20f7d06ecb48b3a68432",
+					},
+					"podLabels": map[string]interface{}{
+						"maintenance.gardener.cloud/restart": "true",
+					},
+					"tlsCipherSuites": []string{
+						"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+						"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
+						"TLS_AES_128_GCM_SHA256",
+						"TLS_AES_256_GCM_SHA384",
+						"TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
+						"TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
+						"TLS_CHACHA20_POLY1305_SHA256",
+						"TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305",
+						"TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305",
+					},
+					"secrets": map[string]interface{}{
+						"server": "cloud-controller-manager-server",
+					},
+					"featureGates": map[string]bool{
+						"CustomResourceValidation": true,
+					},
+					"podNetwork":           "10.0.0.0/16",
+					"configureCloudRoutes": false,
+				},
+				"csi-driver-controller": map[string]interface{}{
+					"enabled":  true,
+					"replicas": 1,
+				},
+			}))
+		})
 	})
 })