Updated Documents page to not use a search key

This change updates the page to rely on basic authentication rather
than a search key.

As part of that, we needed to create a proxy endpoint for search-ui
to post to, rather than going directly to the ent-search API.

x-pack/plugins/enterprise_search/public/applications/app_search/components/documents/search_experience/search_experience.tsx

@@ -18,7 +18,7 @@ import { i18n } from '@kbn/i18n';
 
 import './search_experience.scss';
 
-import { externalUrl } from '../../../../shared/enterprise_search_url';
+import { HttpLogic } from '../../../../shared/http';
 import { useLocalStorage } from '../../../../shared/use_local_storage';
 import { EngineLogic } from '../../engine';
 
@@ -52,7 +52,8 @@ const DEFAULT_SORT_OPTIONS: SortOption[] = [
 
 export const SearchExperience: React.FC = () => {
   const { engine } = useValues(EngineLogic);
-  const endpointBase = externalUrl.enterpriseSearchUrl;
+  const { http } = useValues(HttpLogic);
+  const endpointBase = http.basePath.prepend('/api/app_search/search-ui');
 
   const [showCustomizationModal, setShowCustomizationModal] = useState(false);
   const openCustomizationModal = () => setShowCustomizationModal(true);
@@ -72,7 +73,9 @@ export const SearchExperience: React.FC = () => {
     cacheResponses: false,
     endpointBase,
     engineName: engine.name,
-    searchKey: engine.apiKey,
+    additionalHeaders: {
+      'kbn-xsrf': true,
+    },
   });
 
   const searchProviderConfig = buildSearchUIConfig(connector, engine.schema || {}, fields);

x-pack/plugins/enterprise_search/server/routes/app_search/search.ts

@@ -14,6 +14,8 @@
 
 import { schema } from '@kbn/config-schema';
 
+import { skipBodyValidation } from '../../lib/route_config_helpers';
+
 import { RouteDependencies } from '../../plugin';
 
 export function registerSearchRoutes({
@@ -36,4 +38,25 @@ export function registerSearchRoutes({
       path: '/api/as/v1/engines/:engineName/search.json',
     })
   );
+
+  // For the Search UI routes below, Search UI always uses the full API path, like:
+  // "/api/as/v1/engines/{engineName}/search.json". We only have control over the base path
+  // in Search UI, so we created a common basepath of "/api/app_search/search-ui" here that
+  // Search UI can use.
+  //
+  // Search UI *also* uses the click tracking and query suggestion endpoints, however, since the
+  // App Search plugin doesn't use that portion of Search UI, we only set up a proxy for the search endpoint below.
+  router.post(
+    skipBodyValidation({
+      path: '/api/app_search/search-ui/api/as/v1/engines/{engineName}/search.json',
+      validate: {
+        params: schema.object({
+          engineName: schema.string(),
+        }),
+      },
+    }),
+    enterpriseSearchRequestHandler.createRequest({
+      path: '/api/as/v1/engines/:engineName/search.json',
+    })
+  );
 }