[8.6] [UA] skip system indices migration status check if featureSet.migrateSystemIndices is set to false (#150710) (#150736)

# Backport

This will backport the following commits from `main` to `8.6`:
- [[UA] skip system indices migration status check if
`featureSet.migrateSystemIndices` is set to `false`
(#150710)](https://github.com/elastic/kibana/pull/150710)

<!--- Backport version: 8.9.7 -->

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

<!--BACKPORT [{"author":{"name":"Ahmad
Bamieh","email":"ahmad.bamyeh@elastic.co"},"sourceCommit":{"committedDate":"2023-02-09T16:09:39Z","message":"[UA]
skip system indices migration status check if
`featureSet.migrateSystemIndices` is set to `false`
(#150710)\n\nCo-authored-by: kibanamachine
<42973632+kibanamachine@users.noreply.github.com>","sha":"d2f86398ecc76c0a8a9abdbadcb6d37a693886b9","branchLabelMapping":{"^v8.8.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["bug","release_note:skip","v8.6.2","v8.8.0"],"number":150710,"url":"https://github.com/elastic/kibana/pull/150710","mergeCommit":{"message":"[UA]
skip system indices migration status check if
`featureSet.migrateSystemIndices` is set to `false`
(#150710)\n\nCo-authored-by: kibanamachine
<42973632+kibanamachine@users.noreply.github.com>","sha":"d2f86398ecc76c0a8a9abdbadcb6d37a693886b9"}},"sourceBranch":"main","suggestedTargetBranches":["8.6"],"targetPullRequestStates":[{"branch":"8.6","label":"v8.6.2","labelRegex":"^v(\\d+).(\\d+).\\d+$","isSourceBranch":false,"state":"NOT_CREATED"},{"branch":"main","label":"v8.8.0","labelRegex":"^v8.8.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/150710","number":150710,"mergeCommit":{"message":"[UA]
skip system indices migration status check if
`featureSet.migrateSystemIndices` is set to `false`
(#150710)\n\nCo-authored-by: kibanamachine
<42973632+kibanamachine@users.noreply.github.com>","sha":"d2f86398ecc76c0a8a9abdbadcb6d37a693886b9"}}]}]
BACKPORT-->

Co-authored-by: Ahmad Bamieh <ahmad.bamyeh@elastic.co>

x-pack/plugins/upgrade_assistant/server/routes/status.test.ts

@@ -8,12 +8,13 @@
 import { kibanaResponseFactory } from '@kbn/core/server';
 
 import { handleEsError } from '../shared_imports';
-import { createMockRouter, MockRouter, routeHandlerContextMock } from './__mocks__/routes.mock';
+import { createMockRouter, routeHandlerContextMock } from './__mocks__/routes.mock';
 import { createRequestMock } from './__mocks__/request.mock';
 import { registerUpgradeStatusRoute } from './status';
 import { getESUpgradeStatus } from '../lib/es_deprecations_status';
 import { getKibanaUpgradeStatus } from '../lib/kibana_status';
 import { getESSystemIndicesMigrationStatus } from '../lib/es_system_indices_migration';
+import type { FeatureSet } from '../../common/types';
 
 jest.mock('../lib/es_version_precheck', () => ({
   versionCheckHandlerWrapper: (a: any) => a,
@@ -86,31 +87,33 @@ const systemIndicesNoMigrationResponse = {
 };
 
 describe('Status API', () => {
-  let mockRouter: MockRouter;
-  let routeDependencies: any;
-
-  beforeEach(() => {
-    mockRouter = createMockRouter();
-    routeDependencies = {
+  const registerRoutes = (featureSetOverrides: Partial<FeatureSet> = {}) => {
+    const mockRouter = createMockRouter();
+    const routeDependencies: any = {
       config: {
         featureSet: {
           mlSnapshots: true,
           migrateSystemIndices: true,
           reindexCorrectiveActions: true,
+          ...featureSetOverrides,
         },
       },
       router: mockRouter,
       lib: { handleEsError },
     };
-    registerUpgradeStatusRoute(routeDependencies);
-  });
 
-  afterEach(() => {
-    jest.resetAllMocks();
-  });
+    registerUpgradeStatusRoute(routeDependencies);
+
+    return { mockRouter, routeDependencies };
+  };
 
   describe('GET /api/upgrade_assistant/status', () => {
+    afterEach(() => {
+      jest.resetAllMocks();
+    });
+
     it('returns readyForUpgrade === false if Kibana or ES contain critical deprecations and no system indices need migration', async () => {
+      const { routeDependencies } = registerRoutes();
       getESUpgradeStatusMock.mockResolvedValue(esDeprecationsResponse);
 
       getKibanaUpgradeStatusMock.mockResolvedValue({
@@ -124,6 +127,7 @@ describe('Status API', () => {
         pathPattern: '/api/upgrade_assistant/status',
       })(routeHandlerContextMock, createRequestMock(), kibanaResponseFactory);
 
+      expect(getESSystemIndicesMigrationStatusMock).toBeCalledTimes(1);
       expect(resp.status).toEqual(200);
       expect(resp.payload).toEqual({
         readyForUpgrade: false,
@@ -133,6 +137,7 @@ describe('Status API', () => {
     });
 
     it('returns readyForUpgrade === false if Kibana or ES contain critical deprecations and system indices need migration', async () => {
+      const { routeDependencies } = registerRoutes();
       getESUpgradeStatusMock.mockResolvedValue(esDeprecationsResponse);
 
       getKibanaUpgradeStatusMock.mockResolvedValue({
@@ -146,6 +151,7 @@ describe('Status API', () => {
         pathPattern: '/api/upgrade_assistant/status',
       })(routeHandlerContextMock, createRequestMock(), kibanaResponseFactory);
 
+      expect(getESSystemIndicesMigrationStatusMock).toBeCalledTimes(1);
       expect(resp.status).toEqual(200);
       expect(resp.payload).toEqual({
         readyForUpgrade: false,
@@ -155,6 +161,7 @@ describe('Status API', () => {
     });
 
     it('returns readyForUpgrade === false if no critical Kibana or ES deprecations but system indices need migration', async () => {
+      const { routeDependencies } = registerRoutes();
       getESUpgradeStatusMock.mockResolvedValue(esNoDeprecationsResponse);
 
       getKibanaUpgradeStatusMock.mockResolvedValue({
@@ -168,6 +175,7 @@ describe('Status API', () => {
         pathPattern: '/api/upgrade_assistant/status',
       })(routeHandlerContextMock, createRequestMock(), kibanaResponseFactory);
 
+      expect(getESSystemIndicesMigrationStatusMock).toBeCalledTimes(1);
       expect(resp.status).toEqual(200);
       expect(resp.payload).toEqual({
         readyForUpgrade: false,
@@ -177,6 +185,7 @@ describe('Status API', () => {
     });
 
     it('returns readyForUpgrade === true if there are no critical deprecations and no system indices need migration', async () => {
+      const { routeDependencies } = registerRoutes();
       getESUpgradeStatusMock.mockResolvedValue(esNoDeprecationsResponse);
 
       getKibanaUpgradeStatusMock.mockResolvedValue({
@@ -197,7 +206,30 @@ describe('Status API', () => {
       });
     });
 
+    it('skips ES system indices migration check when featureSet.migrateSystemIndices is set to false', async () => {
+      const { routeDependencies } = registerRoutes({ migrateSystemIndices: false });
+      getESUpgradeStatusMock.mockResolvedValue(esNoDeprecationsResponse);
+
+      getKibanaUpgradeStatusMock.mockResolvedValue({
+        totalCriticalDeprecations: 0,
+      });
+
+      getESSystemIndicesMigrationStatusMock.mockResolvedValue(systemIndicesMigrationResponse);
+      const resp = await routeDependencies.router.getHandler({
+        method: 'get',
+        pathPattern: '/api/upgrade_assistant/status',
+      })(routeHandlerContextMock, createRequestMock(), kibanaResponseFactory);
+
+      expect(getESSystemIndicesMigrationStatusMock).toBeCalledTimes(0);
+      expect(resp.status).toEqual(200);
+      expect(resp.payload).toEqual({
+        readyForUpgrade: true,
+        details: 'All deprecation warnings have been resolved.',
+      });
+    });
+
     it('returns an error if it throws', async () => {
+      const { routeDependencies } = registerRoutes();
       getESUpgradeStatusMock.mockRejectedValue(new Error('test error'));
 
       getKibanaUpgradeStatusMock.mockResolvedValue({

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

@@ -37,9 +37,27 @@ export function registerUpgradeStatusRoute({
           esClient,
           featureSet
         );
-        // Fetch system indices migration status
+
+        const getSystemIndicesMigrationStatus = async () => {
+          /**
+           * Skip system indices migration status check if `featureSet.migrateSystemIndices`
+           * is set to `false`. This flag is enabled from configs for major version stack ugprades.
+           * returns `migration_status: 'NO_MIGRATION_NEEDED'` to indicate no migation needed.
+           */
+          if (!featureSet.migrateSystemIndices) {
+            return {
+              migration_status: 'NO_MIGRATION_NEEDED',
+              features: [],
+            };
+          }
+
+          // Fetch system indices migration status from ES
+          return await getESSystemIndicesMigrationStatus(esClient.asCurrentUser);
+        };
+
         const { migration_status: systemIndicesMigrationStatus, features } =
-          await getESSystemIndicesMigrationStatus(esClient.asCurrentUser);
+          await getSystemIndicesMigrationStatus();
+
         const notMigratedSystemIndices = features.filter(
           (feature) => feature.migration_status !== 'NO_MIGRATION_NEEDED'
         ).length;