[8.x] [watcher] Use ES Watcher API instead of search query (#204296) (#204372)

# Backport

This will backport the following commits from `main` to `8.x`:
- [[watcher] Use ES Watcher API instead of search query
(#204296)](https://github.com/elastic/kibana/pull/204296)

<!--- Backport version: 9.4.3 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Matthew
Kime","email":"matt@mattki.me"},"sourceCommit":{"committedDate":"2024-12-16T12:04:15Z","message":"[watcher]
Use ES Watcher API instead of search query (#204296)\n\n##
Summary\r\n\r\nSimply uses the ES Watcher API to load watches instead of
a search query\r\nagainst the `.watches` index. This appears to be the
last direct query\r\nagainst that index.\r\n\r\nPart of
https://github.com/elastic/kibana/issues/152142","sha":"bc5c0971843f06f250c77a08d60f2a507e099bf4","branchLabelMapping":{"^v9.0.0$":"main","^v8.18.0$":"8.x","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["Feature:Watcher","Team:Kibana
Management","release_note:skip","v9.0.0","backport:prev-minor"],"title":"[watcher]
Use ES Watcher API instead of search
query","number":204296,"url":"https://github.com/elastic/kibana/pull/204296","mergeCommit":{"message":"[watcher]
Use ES Watcher API instead of search query (#204296)\n\n##
Summary\r\n\r\nSimply uses the ES Watcher API to load watches instead of
a search query\r\nagainst the `.watches` index. This appears to be the
last direct query\r\nagainst that index.\r\n\r\nPart of
https://github.com/elastic/kibana/issues/152142","sha":"bc5c0971843f06f250c77a08d60f2a507e099bf4"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.0.0","branchLabelMappingKey":"^v9.0.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/204296","number":204296,"mergeCommit":{"message":"[watcher]
Use ES Watcher API instead of search query (#204296)\n\n##
Summary\r\n\r\nSimply uses the ES Watcher API to load watches instead of
a search query\r\nagainst the `.watches` index. This appears to be the
last direct query\r\nagainst that index.\r\n\r\nPart of
https://github.com/elastic/kibana/issues/152142","sha":"bc5c0971843f06f250c77a08d60f2a507e099bf4"}}]}]
BACKPORT-->

Co-authored-by: Matthew Kime <matt@mattki.me>

x-pack/platform/plugins/private/watcher/common/constants/index_names.ts

@@ -5,7 +5,6 @@
  * 2.0.
  */
 
-export const INDEX_NAMES: { [key: string]: string } = {
-  WATCHES: '.watches',
+export const INDEX_NAMES = {
   WATCHER_HISTORY: '.watcher-history-*',
 };

x-pack/platform/plugins/private/watcher/server/plugin.ts

@@ -60,7 +60,6 @@ export class WatcherServerPlugin implements Plugin<void, void, any, any> {
         {
           requiredClusterPrivileges: ['manage_watcher'],
           requiredIndexPrivileges: {
-            [INDEX_NAMES.WATCHES]: ['read'],
             [INDEX_NAMES.WATCHER_HISTORY]: ['read'],
           },
           ui: [],
@@ -68,7 +67,6 @@ export class WatcherServerPlugin implements Plugin<void, void, any, any> {
         {
           requiredClusterPrivileges: ['monitor_watcher'],
           requiredIndexPrivileges: {
-            [INDEX_NAMES.WATCHES]: ['read'],
             [INDEX_NAMES.WATCHER_HISTORY]: ['read'],
           },
           ui: [],

x-pack/platform/plugins/private/watcher/server/routes/api/watches/register_list_route.ts

@@ -5,29 +5,9 @@
  * 2.0.
  */
 
-import { IScopedClusterClient } from '@kbn/core/server';
-import { get } from 'lodash';
-import { fetchAllFromScroll } from '../../../lib/fetch_all_from_scroll';
-import { INDEX_NAMES, ES_SCROLL_SETTINGS } from '../../../../common/constants';
 import { RouteDependencies } from '../../../types';
-// @ts-ignore
 import { Watch } from '../../../models/watch';
 
-function fetchWatches(dataClient: IScopedClusterClient) {
-  return dataClient.asCurrentUser
-    .search(
-      {
-        index: INDEX_NAMES.WATCHES,
-        scroll: ES_SCROLL_SETTINGS.KEEPALIVE,
-        body: {
-          size: ES_SCROLL_SETTINGS.PAGE_SIZE,
-        },
-      },
-      { ignore: [404] }
-    )
-    .then((body) => fetchAllFromScroll(body, dataClient));
-}
-
 export function registerListRoute({ router, license, lib: { handleEsError } }: RouteDependencies) {
   router.get(
     {
@@ -37,17 +17,13 @@ export function registerListRoute({ router, license, lib: { handleEsError } }: R
     license.guardApiRoute(async (ctx, request, response) => {
       try {
         const esClient = (await ctx.core).elasticsearch.client;
-        const hits = await fetchWatches(esClient);
-        const watches = hits.map((hit: any) => {
-          const id = get(hit, '_id');
-          const watchJson = get(hit, '_source');
-          const watchStatusJson = get(hit, '_source.status');
-
+        const { watches: hits } = await esClient.asCurrentUser.watcher.queryWatches();
+        const watches = hits.map(({ _id, watch, status }) => {
           return Watch.fromUpstreamJson(
             {
-              id,
-              watchJson,
-              watchStatusJson,
+              id: _id,
+              watchJson: watch,
+              watchStatusJson: status,
             },
             {
               throwExceptions: {

x-pack/test/functional/apps/index_management/feature_controls/index_management_security.ts

@@ -73,7 +73,7 @@ export default function ({ getPageObjects, getService }: FtrProviderContext) {
 
           // The index_management_user has been given permissions to advanced settings for Stack Management Tests.
           // https://github.com/elastic/kibana/pull/113078/
-          expect(sections).to.have.length(2);
+          expect(sections).to.have.length(3);
           expect(sections[0]).to.eql({
             sectionId: 'data',
             sectionLinks: ['index_management', 'transform'],