[Upgrade Assistant] Add warning when remote clusters are configured

x-pack/plugins/remote_clusters/kibana.json

@@ -6,7 +6,7 @@
     "name": "Stack Management",
     "githubTeam": "kibana-stack-management"
   },
-  "requiredPlugins": ["licensing", "management", "indexManagement", "features"],
+  "requiredPlugins": ["licensing", "management", "indexManagement", "features", "share"],
   "optionalPlugins": ["usageCollection", "cloud"],
   "server": true,
   "ui": true,

x-pack/plugins/remote_clusters/public/locator.ts

@@ -0,0 +1,44 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import type { SerializableRecord } from '@kbn/utility-types';
+import { ManagementAppLocator } from 'src/plugins/management/common';
+import { LocatorDefinition } from '../../../../src/plugins/share/public/';
+
+export const REMOTE_CLUSTERS_LOCATOR_ID = 'REMOTE_CLUSTERS_LOCATOR';
+
+export interface RemoteClustersLocatorParams extends SerializableRecord {
+  page: 'remoteClusters';
+}
+
+export interface RemoteClustersLocatorDefinitionDependencies {
+  managementAppLocator: ManagementAppLocator;
+}
+
+export class RemoteClustersLocatorDefinition
+  implements LocatorDefinition<RemoteClustersLocatorParams>
+{
+  constructor(protected readonly deps: RemoteClustersLocatorDefinitionDependencies) {}
+
+  public readonly id = REMOTE_CLUSTERS_LOCATOR_ID;
+
+  public readonly getLocation = async (params: RemoteClustersLocatorParams) => {
+    const location = await this.deps.managementAppLocator.getLocation({
+      sectionId: 'data',
+      appId: 'remote_clusters',
+    });
+
+    switch (params.page) {
+      case 'remoteClusters': {
+        return {
+          ...location,
+          path: location.path,
+        };
+      }
+    }
+  };
+}

x-pack/plugins/remote_clusters/public/plugin.ts

@@ -16,6 +16,7 @@ import { init as initUiMetric } from './application/services/ui_metric';
 import { init as initNotification } from './application/services/notification';
 import { init as initRedirect } from './application/services/redirect';
 import { Dependencies, ClientConfigType } from './types';
+import { RemoteClustersLocatorDefinition } from './locator';
 
 export interface RemoteClustersPluginSetup {
   isUiEnabled: boolean;
@@ -28,7 +29,7 @@ export class RemoteClustersUIPlugin
 
   setup(
     { notifications: { toasts }, http, getStartServices }: CoreSetup,
-    { management, usageCollection, cloud }: Dependencies
+    { management, usageCollection, cloud, share }: Dependencies
   ) {
     const {
       ui: { enabled: isRemoteClustersUiEnabled },
@@ -79,6 +80,12 @@ export class RemoteClustersUIPlugin
           };
         },
       });
+
+      share.url.locators.create(
+        new RemoteClustersLocatorDefinition({
+          managementAppLocator: management.locator,
+        })
+      );
     }
 
     return {

x-pack/plugins/remote_clusters/public/types.ts

@@ -8,13 +8,15 @@
 import { ManagementSetup } from 'src/plugins/management/public';
 import { UsageCollectionSetup } from 'src/plugins/usage_collection/public';
 import { RegisterManagementAppArgs } from 'src/plugins/management/public';
+import { SharePluginSetup } from 'src/plugins/share/public';
 import { I18nStart } from 'kibana/public';
 import { CloudSetup } from '../../cloud/public';
 
 export interface Dependencies {
   management: ManagementSetup;
   usageCollection: UsageCollectionSetup;
   cloud: CloudSetup;
+  share: SharePluginSetup;
 }
 
 export interface ClientConfigType {

x-pack/plugins/upgrade_assistant/__jest__/client_integration/es_deprecations/deprecations_list.test.ts

@@ -44,6 +44,7 @@ describe('ES deprecations table', () => {
         aliases: [],
       },
     });
+    httpRequestsMockHelpers.setLoadRemoteClustersResponse([]);
 
     await act(async () => {
       testBed = await setupElasticsearchPage({ isReadOnlyMode: false });
@@ -105,6 +106,25 @@ describe('ES deprecations table', () => {
     expect(find('warningDeprecationsCount').text()).toContain(warningDeprecations.length);
   });
 
+  describe('remote clusters callout', () => {
+    beforeEach(async () => {
+      httpRequestsMockHelpers.setLoadRemoteClustersResponse(['test_remote_cluster']);
+
+      await act(async () => {
+        testBed = await setupElasticsearchPage({ isReadOnlyMode: false });
+      });
+
+      testBed.component.update();
+    });
+
+    it('shows a warning message if a user has remote clusters configured', () => {
+      const { exists } = testBed;
+
+      // Verify warning exists
+      expect(exists('remoteClustersWarningCallout')).toBe(true);
+    });
+  });
+
   describe('search bar', () => {
     it('filters results by "critical" status', async () => {
       const { find, actions } = testBed;

x-pack/plugins/upgrade_assistant/__jest__/client_integration/helpers/http_requests.ts

@@ -203,6 +203,17 @@ const registerHttpRequestMockHelpers = (server: SinonFakeServer) => {
     ]);
   };
 
+  const setLoadRemoteClustersResponse = (response?: object, error?: ResponseError) => {
+    const status = error ? error.statusCode || 400 : 200;
+    const body = error ? error : response;
+
+    server.respondWith('GET', `${API_BASE_PATH}/remote_clusters`, [
+      status,
+      { 'Content-Type': 'application/json' },
+      JSON.stringify(body),
+    ]);
+  };
+
   return {
     setLoadCloudBackupStatusResponse,
     setLoadEsDeprecationsResponse,
@@ -220,6 +231,7 @@ const registerHttpRequestMockHelpers = (server: SinonFakeServer) => {
     setReindexStatusResponse,
     setLoadMlUpgradeModeResponse,
     setGetUpgradeStatusResponse,
+    setLoadRemoteClustersResponse,
   };
 };
 

x-pack/plugins/upgrade_assistant/public/application/components/es_deprecations/es_deprecations.tsx

@@ -8,7 +8,7 @@
 import React, { useEffect, useMemo } from 'react';
 import { withRouter, RouteComponentProps } from 'react-router-dom';
 
-import { EuiPageHeader, EuiSpacer, EuiPageContent, EuiLink } from '@elastic/eui';
+import { EuiPageHeader, EuiSpacer, EuiPageContent, EuiLink, EuiCallOut } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import { FormattedMessage } from '@kbn/i18n-react';
 import { DocLinksStart } from 'kibana/public';
@@ -51,6 +51,26 @@ const i18nTexts = {
   isLoading: i18n.translate('xpack.upgradeAssistant.esDeprecations.loadingText', {
     defaultMessage: 'Loading deprecation issues…',
   }),
+  remoteClustersDetectedTitle: i18n.translate(
+    'xpack.upgradeAssistant.esDeprecations.remoteClustersDetectedTitle',
+    {
+      defaultMessage: 'Remote cluster compatibility',
+    }
+  ),
+  getRemoteClustersDetectedDescription: (remoteClustersCount: number) =>
+    i18n.translate('xpack.upgradeAssistant.esDeprecations.remoteClustersDetectedDescription', {
+      defaultMessage:
+        'You have {remoteClustersCount} {remoteClustersCount, plural, one {remote cluster} other {remote clusters}} configured. If you use cross-cluster search, note that 8.x can only search remote clusters running the previous minor version or later. If you use cross-cluster replication, a cluster that contains follower indices must run the same or newer version as the remote cluster.',
+      values: {
+        remoteClustersCount,
+      },
+    }),
+  remoteClustersLinkText: i18n.translate(
+    'xpack.upgradeAssistant.esDeprecations.remoteClustersLinkText',
+    {
+      defaultMessage: 'View remote clusters.',
+    }
+  ),
 };
 
 const getBatchReindexLink = (docLinks: DocLinksStart) => {
@@ -75,6 +95,22 @@ const getBatchReindexLink = (docLinks: DocLinksStart) => {
   );
 };
 
+const RemoteClustersAppLink: React.FunctionComponent = () => {
+  const {
+    plugins: { share },
+  } = useAppContext();
+
+  const remoteClustersUrl = share.url.locators
+    .get('REMOTE_CLUSTERS_LOCATOR')
+    ?.useUrl({ page: 'remoteClusters' });
+
+  return (
+    <EuiLink href={remoteClustersUrl} data-test-subj="remoteClustersLink">
+      {i18nTexts.remoteClustersLinkText}
+    </EuiLink>
+  );
+};
+
 export const EsDeprecations = withRouter(({ history }: RouteComponentProps) => {
   const {
     services: {
@@ -85,6 +121,7 @@ export const EsDeprecations = withRouter(({ history }: RouteComponentProps) => {
   } = useAppContext();
 
   const { data: esDeprecations, isLoading, error, resendRequest } = api.useLoadEsDeprecations();
+  const { data: remoteClusters } = api.useLoadRemoteClusters();
 
   const deprecationsCountByLevel: {
     warningDeprecations: number;
@@ -140,10 +177,29 @@ export const EsDeprecations = withRouter(({ history }: RouteComponentProps) => {
           </>
         }
       >
-        <DeprecationCount
-          totalCriticalDeprecations={deprecationsCountByLevel.criticalDeprecations}
-          totalWarningDeprecations={deprecationsCountByLevel.warningDeprecations}
-        />
+        <>
+          {remoteClusters && remoteClusters.length > 0 && (
+            <>
+              <EuiCallOut
+                title={i18nTexts.remoteClustersDetectedTitle}
+                color="warning"
+                iconType="help"
+                data-test-subj="remoteClustersWarningCallout"
+              >
+                <p>
+                  {i18nTexts.getRemoteClustersDetectedDescription(remoteClusters.length)}{' '}
+                  <RemoteClustersAppLink />
+                </p>
+              </EuiCallOut>
+              <EuiSpacer />
+            </>
+          )}
+
+          <DeprecationCount
+            totalCriticalDeprecations={deprecationsCountByLevel.criticalDeprecations}
+            totalWarningDeprecations={deprecationsCountByLevel.warningDeprecations}
+          />
+        </>
       </EuiPageHeader>
 
       <EuiSpacer size="l" />

x-pack/plugins/upgrade_assistant/public/application/lib/api.ts

@@ -239,6 +239,13 @@ export class ApiService {
       method: 'get',
     });
   }
+
+  public useLoadRemoteClusters() {
+    return this.useRequest<string[]>({
+      path: `${API_BASE_PATH}/remote_clusters`,
+      method: 'get',
+    });
+  }
 }
 
 export const apiService = new ApiService();

x-pack/plugins/upgrade_assistant/server/routes/register_routes.ts

@@ -18,6 +18,7 @@ import { registerUpdateSettingsRoute } from './update_index_settings';
 import { registerMlSnapshotRoutes } from './ml_snapshots';
 import { ReindexWorker } from '../lib/reindexing';
 import { registerUpgradeStatusRoute } from './status';
+import { registerRemoteClustersRoute } from './remote_clusters';
 
 export function registerRoutes(dependencies: RouteDependencies, getWorker: () => ReindexWorker) {
   registerAppRoutes(dependencies);
@@ -32,4 +33,5 @@ export function registerRoutes(dependencies: RouteDependencies, getWorker: () =>
   registerMlSnapshotRoutes(dependencies);
   // Route for cloud to retrieve the upgrade status for ES and Kibana
   registerUpgradeStatusRoute(dependencies);
+  registerRemoteClustersRoute(dependencies);
 }

x-pack/plugins/upgrade_assistant/server/routes/remote_clusters.ts

@@ -0,0 +1,40 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { API_BASE_PATH } from '../../common/constants';
+import { versionCheckHandlerWrapper } from '../lib/es_version_precheck';
+import { RouteDependencies } from '../types';
+
+export function registerRemoteClustersRoute({ router, lib: { handleEsError } }: RouteDependencies) {
+  router.get(
+    {
+      path: `${API_BASE_PATH}/remote_clusters`,
+      validate: false,
+    },
+    versionCheckHandlerWrapper(
+      async (
+        {
+          core: {
+            elasticsearch: { client },
+          },
+        },
+        request,
+        response
+      ) => {
+        try {
+          const { body: clustersByName } = await client.asCurrentUser.cluster.remoteInfo();
+
+          const remoteClusters = Object.keys(clustersByName);
+
+          return response.ok({ body: remoteClusters });
+        } catch (error) {
+          return handleEsError({ error, response });
+        }
+      }
+    )
+  );
+}

x-pack/test/api_integration/apis/upgrade_assistant/index.ts

@@ -14,5 +14,6 @@ export default function ({ loadTestFile }: FtrProviderContext) {
     loadTestFile(require.resolve('./privileges'));
     loadTestFile(require.resolve('./es_deprecations'));
     loadTestFile(require.resolve('./es_deprecation_logs'));
+    loadTestFile(require.resolve('./remote_clusters'));
   });
 }