replace /elasticsearch/_msearch usages with custom endpoint

src/plugins/home/public/application/components/tutorial/tutorial.js

@@ -201,26 +201,18 @@ class TutorialUi extends React.Component {
    * @return {Promise<string>}
    */
   fetchEsHitsStatus = async (esHitsCheckConfig) => {
-    const searchHeader = JSON.stringify({ index: esHitsCheckConfig.index });
-    const searchBody = JSON.stringify({ query: esHitsCheckConfig.query, size: 1 });
-    const response = await fetch(this.props.addBasePath('/elasticsearch/_msearch'), {
-      method: 'post',
-      body: `${searchHeader}\n${searchBody}\n`,
-      headers: {
-        accept: 'application/json',
-        'content-type': 'application/x-ndjson',
-        'kbn-xsrf': 'kibana',
-      },
-      credentials: 'same-origin',
-    });
-
-    if (response.status > 300) {
+    const { http } = getServices();
+    try {
+      const response = await http.post('/api/home/hits_status', {
+        body: JSON.stringify({
+          index: esHitsCheckConfig.index,
+          query: esHitsCheckConfig.query,
+        }),
+      });
+      return response.count > 0 ? StatusCheckStates.HAS_DATA : StatusCheckStates.NO_DATA;
+    } catch (e) {
       return StatusCheckStates.ERROR;
     }
-
-    const results = await response.json();
-    const numHits = _.get(results, 'responses.[0].hits.hits.length', 0);
-    return numHits === 0 ? StatusCheckStates.NO_DATA : StatusCheckStates.HAS_DATA;
   };
 
   renderInstructionSetsToggle = () => {

src/plugins/home/server/plugin.test.ts

@@ -19,10 +19,7 @@
 
 import { registryForTutorialsMock, registryForSampleDataMock } from './plugin.test.mocks';
 import { HomeServerPlugin } from './plugin';
-import { coreMock } from '../../../core/server/mocks';
-import { CoreSetup } from '../../../core/server';
-
-type MockedKeys<T> = { [P in keyof T]: jest.Mocked<T[P]> };
+import { coreMock, httpServiceMock } from '../../../core/server/mocks';
 
 describe('HomeServerPlugin', () => {
   beforeEach(() => {
@@ -33,8 +30,16 @@ describe('HomeServerPlugin', () => {
   });
 
   describe('setup', () => {
-    const mockCoreSetup: MockedKeys<CoreSetup> = coreMock.createSetup();
-    const initContext = coreMock.createPluginInitializerContext();
+    let mockCoreSetup: ReturnType<typeof coreMock.createSetup>;
+    let initContext: ReturnType<typeof coreMock.createPluginInitializerContext>;
+    let routerMock: ReturnType<typeof httpServiceMock.createRouter>;
+
+    beforeEach(() => {
+      mockCoreSetup = coreMock.createSetup();
+      routerMock = httpServiceMock.createRouter();
+      mockCoreSetup.http.createRouter.mockReturnValue(routerMock);
+      initContext = coreMock.createPluginInitializerContext();
+    });
 
     test('wires up tutorials provider service and returns registerTutorial and addScopedTutorialContextFactory', () => {
       const setup = new HomeServerPlugin(initContext).setup(mockCoreSetup, {});
@@ -52,6 +57,18 @@ describe('HomeServerPlugin', () => {
       expect(setup.sampleData).toHaveProperty('addAppLinksToSampleDataset');
       expect(setup.sampleData).toHaveProperty('replacePanelInSampleDatasetDashboard');
     });
+
+    test('registers the `/api/home/hits_status` route', () => {
+      new HomeServerPlugin(initContext).setup(mockCoreSetup, {});
+
+      expect(routerMock.post).toHaveBeenCalledTimes(1);
+      expect(routerMock.post).toHaveBeenCalledWith(
+        expect.objectContaining({
+          path: '/api/home/hits_status',
+        }),
+        expect.any(Function)
+      );
+    });
   });
 
   describe('start', () => {

src/plugins/home/server/plugin.ts

@@ -28,6 +28,7 @@ import {
 import { UsageCollectionSetup } from '../../usage_collection/server';
 import { capabilitiesProvider } from './capabilities_provider';
 import { sampleDataTelemetry } from './saved_objects';
+import { registerRoutes } from './routes';
 
 interface HomeServerPluginSetupDependencies {
   usageCollection?: UsageCollectionSetup;
@@ -41,6 +42,10 @@ export class HomeServerPlugin implements Plugin<HomeServerPluginSetup, HomeServe
   public setup(core: CoreSetup, plugins: HomeServerPluginSetupDependencies): HomeServerPluginSetup {
     core.capabilities.registerProvider(capabilitiesProvider);
     core.savedObjects.registerType(sampleDataTelemetry);
+
+    const router = core.http.createRouter();
+    registerRoutes(router);
+
     return {
       tutorials: { ...this.tutorialsRegistry.setup(core) },
       sampleData: { ...this.sampleDataRegistry.setup(core, plugins.usageCollection) },

src/plugins/home/server/routes/fetch_es_hits_status.ts

@@ -0,0 +1,60 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License 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 { schema } from '@kbn/config-schema';
+import { IRouter } from 'src/core/server';
+
+export const registerHitsStatusRoute = (router: IRouter) => {
+  router.post(
+    {
+      path: '/api/home/hits_status',
+      validate: {
+        body: schema.object({
+          index: schema.string(),
+          query: schema.recordOf(schema.string(), schema.any()),
+        }),
+      },
+    },
+    router.handleLegacyErrors(async (context, req, res) => {
+      const { index, query } = req.body;
+      const client = context.core.elasticsearch.client;
+
+      try {
+        const { body } = await client.asCurrentUser.search({
+          index,
+          size: 1,
+          body: {
+            query,
+          },
+        });
+        const count = body.hits.hits.length;
+
+        return res.ok({
+          body: {
+            count,
+          },
+        });
+      } catch (e) {
+        return res.badRequest({
+          body: e,
+        });
+      }
+    })
+  );
+};

src/plugins/home/server/routes/index.ts

@@ -0,0 +1,25 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License 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 { IRouter } from 'src/core/server';
+import { registerHitsStatusRoute } from './fetch_es_hits_status';
+
+export const registerRoutes = (router: IRouter) => {
+  registerHitsStatusRoute(router);
+};