Service template support for remoteClusterServer interface

docs/reference/api-reference/main.md

@@ -671,6 +671,7 @@ ServiceTemplate defines the template for a Kubernetes Service.
 :::{admonition} Appears In:
 * [HTTPConfig](#httpconfig)
 * [LogstashService](#logstashservice)
+* [RemoteClusterServer](#remoteclusterserver)
 * [TransportConfig](#transportconfig)
 
 :::
@@ -1276,6 +1277,7 @@ RemoteClusterAccess models the API key specification as documented in https://ww
 | Field | Description |
 | --- | --- |
 | *`enabled`* __boolean__ |  |
+| *`service`* __[ServiceTemplate](#servicetemplate)__ | Service defines the template for the remote cluster server Service object. |
 
 
 ### Replication  [#replication]

pkg/apis/elasticsearch/v1/elasticsearch_types.go

@@ -155,6 +155,8 @@ type ElasticsearchSpec struct {
 type RemoteClusterServer struct {
 	// +kubebuilder:validation:Optional
 	Enabled bool `json:"enabled,omitempty"`
+	// Service defines the template for the remote cluster server Service object.
+	Service commonv1.ServiceTemplate `json:"service,omitempty"`
 }
 
 // VolumeClaimDeletePolicy describes the delete policy for handling PersistentVolumeClaims that hold Elasticsearch data.

pkg/controller/elasticsearch/services/services.go

@@ -161,29 +161,31 @@ func NewInternalService(es esv1.Elasticsearch, meta metadata.Metadata) *corev1.S
 
 // NewRemoteClusterService returns the service associated to the remote cluster service for the given cluster.
 func NewRemoteClusterService(es esv1.Elasticsearch, meta metadata.Metadata) *corev1.Service {
-	svc := &corev1.Service{
-		ObjectMeta: metav1.ObjectMeta{
-			Name:        RemoteClusterServiceName(es.Name),
-			Namespace:   es.Namespace,
-			Labels:      meta.Labels,
-			Annotations: meta.Annotations,
-		},
-		Spec: corev1.ServiceSpec{
-			Type:                     corev1.ServiceTypeClusterIP,
-			Selector:                 label.NewLabels(k8s.ExtractNamespacedName(&es)),
-			PublishNotReadyAddresses: true,
-			ClusterIP:                "None",
-		},
+	nsn := k8s.ExtractNamespacedName(&es)
+	svc := corev1.Service{
+		ObjectMeta: es.Spec.RemoteClusterServer.Service.ObjectMeta,
+		Spec:       es.Spec.RemoteClusterServer.Service.Spec,
 	}
-	selector := label.NewLabels(k8s.ExtractNamespacedName(&es))
+
+	svc.ObjectMeta.Namespace = es.Namespace
+	svc.ObjectMeta.Name = RemoteClusterServiceName(es.Name)
+	// Allow connections to pods that are not yet ready
+	svc.Spec.PublishNotReadyAddresses = true
+	if svc.Spec.Type == "" {
+		svc.Spec.Type = corev1.ServiceTypeClusterIP
+		// ClusterIP None creates a headless service, allowing direct access to all pods for remote cluster connections
+		svc.Spec.ClusterIP = "None"
+	}
+	selector := label.NewLabels(nsn)
 	ports := []corev1.ServicePort{
 		{
 			Name:     RemoteClusterServicePortName,
 			Protocol: corev1.ProtocolTCP,
 			Port:     network.RemoteClusterPort,
 		},
 	}
-	return defaults.SetServiceDefaults(svc, meta, selector, ports)
+
+	return defaults.SetServiceDefaults(&svc, meta, selector, ports)
 }
 
 type urlProvider struct {

pkg/controller/elasticsearch/services/services_test.go

@@ -284,6 +284,92 @@ func TestNewTransportService(t *testing.T) {
 	}
 }
 
+func mkRemoteClusterService() corev1.Service {
+	return corev1.Service{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "elasticsearch-test-es-remote-cluster",
+			Namespace: "test",
+			Labels: map[string]string{
+				label.ClusterNameLabelName: "elasticsearch-test",
+				commonv1.TypeLabelName:     label.Type,
+			},
+		},
+		Spec: corev1.ServiceSpec{
+			PublishNotReadyAddresses: true,
+			ClusterIP:                "None",
+			Type:                     corev1.ServiceTypeClusterIP,
+			Ports: []corev1.ServicePort{
+				{
+					Name:     RemoteClusterServicePortName,
+					Protocol: corev1.ProtocolTCP,
+					Port:     network.RemoteClusterPort,
+				},
+			},
+			Selector: map[string]string{
+				label.ClusterNameLabelName: "elasticsearch-test",
+				commonv1.TypeLabelName:     label.Type,
+			},
+		},
+	}
+}
+
+func TestNewRemoteClusterService(t *testing.T) {
+	tests := []struct {
+		name                string
+		remoteClusterServer esv1.RemoteClusterServer
+		want                func() corev1.Service
+	}{
+		{
+			name: "Sets defaults",
+			remoteClusterServer: esv1.RemoteClusterServer{
+				Enabled: true,
+			},
+			want: mkRemoteClusterService,
+		},
+		{
+			name: "Respects user provided template",
+			remoteClusterServer: esv1.RemoteClusterServer{
+				Enabled: true,
+				Service: commonv1.ServiceTemplate{
+					ObjectMeta: metav1.ObjectMeta{
+						Annotations: map[string]string{
+							"my-custom": "annotation",
+						},
+					},
+					Spec: corev1.ServiceSpec{
+						Type: corev1.ServiceTypeLoadBalancer,
+					},
+				},
+			},
+			want: func() corev1.Service {
+				svc := mkRemoteClusterService()
+				svc.ObjectMeta.Annotations = map[string]string{
+					"my-custom": "annotation",
+				}
+				svc.Spec.Type = corev1.ServiceTypeLoadBalancer
+				svc.Spec.ClusterIP = ""
+				return svc
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			es := esv1.Elasticsearch{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "elasticsearch-test",
+					Namespace: "test",
+				},
+				Spec: esv1.ElasticsearchSpec{
+					RemoteClusterServer: tt.remoteClusterServer,
+				},
+			}
+			want := tt.want()
+			got := NewRemoteClusterService(es, metadata.Propagate(&es, metadata.Metadata{Labels: es.GetIdentityLabels()}))
+			require.Nil(t, deep.Equal(*got, want))
+		})
+	}
+}
+
 func Test_urlProvider_PodURL(t *testing.T) {
 	type fields struct {
 		pods   func() ([]corev1.Pod, error)