add instruction view for tenant list when multitenancy is disabled (o…

…pensearch-project#546)

* add instruction view for tenant list when multitenancy is disabled

* wording update by UX

public/apps/configuration/panels/tenant-list/tenant-instruction-view.tsx

@@ -0,0 +1,37 @@
+/*
+ *   Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *   Licensed under the Apache License, Version 2.0 (the "License").
+ *   You may not use this file except in compliance with the License.
+ *   A copy of the License is located at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   or in the "license" file accompanying this file. This file is distributed
+ *   on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *   express or implied. See the License for the specific language governing
+ *   permissions and limitations under the License.
+ */
+
+import React from 'react';
+import { EuiSpacer, EuiText, EuiTitle } from '@elastic/eui';
+
+export function TenantInstructionView() {
+  return (
+    <>
+      <EuiTitle size="l">
+        <h1>Tenants</h1>
+      </EuiTitle>
+
+      <EuiSpacer size="xxl" />
+
+      <EuiText textAlign="center">
+        <h2>You have not enabled multi tenancy</h2>
+      </EuiText>
+
+      <EuiText textAlign="center" size="xs" color="subdued" className="instruction-text">
+        Contact your administrator to enable multi tenancy.
+      </EuiText>
+    </>
+  );
+}

public/apps/configuration/panels/tenant-list/tenant-list.tsx

@@ -31,7 +31,7 @@ import {
   EuiGlobalToastList,
   Query,
 } from '@elastic/eui';
-import React, { ReactNode, useEffect, useState, useCallback } from 'react';
+import React, { ReactNode, useState, useCallback } from 'react';
 import { difference } from 'lodash';
 import { getCurrentUser } from '../../../../utils/auth-info-utils';
 import { AppDependencies } from '../../../types';
@@ -59,6 +59,7 @@ import { showTableStatusMessage } from '../../utils/loading-spinner-utils';
 import { useContextMenuState } from '../../utils/context-menu';
 import { generateResourceName } from '../../utils/resource-utils';
 import { DocLinks } from '../../constants';
+import { TenantInstructionView } from './tenant-instruction-view';
 
 export function TenantList(props: AppDependencies) {
   const [tenantData, setTenantData] = React.useState<Tenant[]>([]);
@@ -319,6 +320,10 @@ export function TenantList(props: AppDependencies) {
     );
   };
 
+  if (!props.config.multitenancy.enabled) {
+    return <TenantInstructionView />;
+  }
+
   return (
     <>
       <EuiPageHeader>