service: &v1.Service{
				ObjectMeta: metav1.ObjectMeta{Namespace: "foo", Name: "bar"},
				Spec: v1.ServiceSpec{
					ClusterIP: "",
				},
			},
			shouldSkip: true,
		},
		{
			// ExternalName type service
			service: &v1.Service{
				ObjectMeta: metav1.ObjectMeta{Namespace: "foo", Name: "bar"},
				Spec: v1.ServiceSpec{
					ClusterIP: "1.2.3.4",
					Type:      v1.ServiceTypeExternalName,
				},
			},

	Hostname  host.Name
	Namespace string
}

type K8sAttributes struct {
	// Type holds the value of the corev1.Type of the Kubernetes service
	// spec.Type
	Type string

	// spec.ExternalName
	ExternalName string

	// NodeLocal means the proxy will only forward traffic to node local endpoints
	// spec.InternalTrafficPolicy == Local
	NodeLocal bool
}

  // (if supported in the current cloud) which routes to the same endpoints
  // as the clusterIP.
  // "ExternalName" aliases this service to the specified externalName.
  // Several other fields do not apply to ExternalName services.
  // More info: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types
  // +optional
  optional string type = 4;

			},
		})
	}
	service := `apiVersion: v1
kind: Service
metadata:
  name: alias
  namespace: default
spec:
  type: ExternalName
  externalName: concrete.default.svc.cluster.local
` + `---
apiVersion: v1
kind: Service
metadata:
  name: concrete
  namespace: default
spec:
  clusterIP: 1.2.3.4
  ports:` + ports

	// Description: Proxy may prevent tcp named ports and unmatched traffic for ports serving TCP protocol from being forwarded correctly for ExternalName services.
	ExternalNameServiceTypeInvalidPortName = diag.NewMessageType(diag.Warning, "IST0150", "Port name for ExternalName service is invalid. Proxy may prevent tcp named ports and unmatched traffic for ports serving TCP protocol from being forwarded correctly")

func resolveServiceAliases(allServices []*Service, configsUpdated sets.Set[ConfigKey]) {
	// rawAlias builds a map of Service -> AliasFor. So this will be ExternalName -> Service.
	// In an edge case, we can have ExternalName -> ExternalName; we resolve that below.
	rawAlias := map[NamespacedHostname]host.Name{}
	for _, s := range allServices {
		if s.Resolution != Alias {
			continue
		}

	// externalName is the external reference that discovery mechanisms will
	// return as an alias for this service (e.g. a DNS CNAME record). No
	// proxying will be involved.  Must be a lowercase RFC-1123 hostname
	// (https://tools.ietf.org/html/rfc1123) and requires `type` to be "ExternalName".
	// +optional
	ExternalName string `json:"externalName,omitempty" protobuf:"bytes,10,opt,name=externalName"`

		if svc.Spec.Type != corev1.ServiceTypeExternalName {
			continue
		}
		res := ObjectToInstance(&svc)
		messages.Add(msg.NewUpdateIncompatibility(res,
			"ENABLE_EXTERNAL_NAME_ALIAS", "1.20",
			"ExternalName services now behavior differently; consult upgrade notes for more information", "1.20"))

	}
	return nil
}

func checkPilot(cli kube.CLIClient, namespace string, messages *diag.Messages) error {

			defer storage.Store.DestroyFunc()

			for _, itc := range otc.cases {
				t.Run(itc.name, func(t *testing.T) {
					// This test is ONLY ExternalName services.
					itc.svc.Spec.Type = api.ServiceTypeExternalName
					itc.svc.Spec.ExternalName = "example.com"

					ctx := genericapirequest.NewDefaultContext()

	{
		Name:        "strict",
		OnlyRunType: v3.ListenerType,
	},
	{
		Name:        "disabled",
		OnlyRunType: v3.ListenerType,
	},

	{
		Name:     "externalname",
		Services: 100,
	},

	// Test usage of various APIs
	{
		Name:     "telemetry-api",
		Services: 100,
	},
	{
		Name:     "virtualservice",
		Services: 100,
	},
	{