[Fleet] Fix fleet_server_hosts value in fleet/settings API (#144898)

## Summary

Resolve `fleet_server_hosts` from the new Fleet Server Host SO type
instead of the settings SO.

Would like to add an integration test for this, but requires setting up
a new "get settings" suite. Will push a follow-up commit.

Fixes https://github.com/elastic/fleet-server/issues/2068

### Checklist

- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios


![image](https://user-images.githubusercontent.com/6766512/200846767-81111fd7-5609-47b1-932d-9274c257f0be.png)

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/fleet/server/collectors/fleet_server_collector.ts

@@ -5,11 +5,11 @@
  * 2.0.
  */
 
-import { isBoom } from '@hapi/boom';
 import type { SavedObjectsClient, ElasticsearchClient } from '@kbn/core/server';
 
-import { packagePolicyService, settingsService } from '../services';
+import { packagePolicyService } from '../services';
 import { getAgentStatusForAgentPolicy } from '../services/agents';
+import { listFleetServerHosts } from '../services/fleet_server_host';
 
 const DEFAULT_USAGE = {
   total_all_statuses: 0,
@@ -39,16 +39,8 @@ export const getFleetServerUsage = async (
     return DEFAULT_USAGE;
   }
 
-  const numHostsUrls = await settingsService
-    .getSettings(soClient)
-    .then((settings) => settings.fleet_server_hosts?.length ?? 0)
-    .catch((err) => {
-      if (isBoom(err) && err.output.statusCode === 404) {
-        return 0;
-      }
-
-      throw err;
-    });
+  const fleetServerHosts = await listFleetServerHosts(soClient);
+  const numHostsUrls = fleetServerHosts.items.flatMap((host) => host.host_urls).length;
 
   // Find all policies with Fleet server than query agent status
   let hasMore = true;

x-pack/plugins/fleet/server/services/settings.ts

@@ -13,6 +13,7 @@ import { GLOBAL_SETTINGS_SAVED_OBJECT_TYPE, GLOBAL_SETTINGS_ID } from '../../com
 import type { SettingsSOAttributes, Settings, BaseSettings } from '../../common/types';
 
 import { appContextService } from './app_context';
+import { listFleetServerHosts } from './fleet_server_host';
 
 export async function getSettings(soClient: SavedObjectsClientContract): Promise<Settings> {
   const res = await soClient.find<SettingsSOAttributes>({
@@ -23,10 +24,12 @@ export async function getSettings(soClient: SavedObjectsClientContract): Promise
     throw Boom.notFound('Global settings not found');
   }
   const settingsSo = res.saved_objects[0];
+  const fleetServerHosts = await listFleetServerHosts(soClient);
+
   return {
     id: settingsSo.id,
     ...settingsSo.attributes,
-    fleet_server_hosts: settingsSo.attributes.fleet_server_hosts || [],
+    fleet_server_hosts: fleetServerHosts.items.flatMap((item) => item.host_urls),
     preconfigured_fields: getConfigFleetServerHosts() ? ['fleet_server_hosts'] : [],
   };
 }

x-pack/test/fleet_api_integration/apis/fleet_telemetry.ts

@@ -81,9 +81,14 @@ export default function (providerContext: FtrProviderContext) {
       }
 
       await supertest
-        .put(`/api/fleet/settings`)
+        .post(`/api/fleet/fleet_server_hosts`)
         .set('kbn-xsrf', 'xxxx')
-        .send({ fleet_server_hosts: ['https://test1.fr', 'https://test2.fr'] })
+        .send({
+          id: 'test-default-123',
+          name: 'Default',
+          is_default: true,
+          host_urls: ['https://test.com:8080', 'https://test.com:8081'],
+        })
         .expect(200);
 
       // Default Fleet Server

x-pack/test/fleet_api_integration/apis/settings/get.ts

@@ -0,0 +1,56 @@
+/*
+ * 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 expect from '@kbn/expect';
+import { FtrProviderContext } from '../../../api_integration/ftr_provider_context';
+import { skipIfNoDockerRegistry } from '../../helpers';
+import { setupFleetAndAgents } from '../agents/services';
+
+export default function (providerContext: FtrProviderContext) {
+  const { getService } = providerContext;
+  const supertest = getService('supertest');
+  const esArchiver = getService('esArchiver');
+  const kibanaServer = getService('kibanaServer');
+
+  describe('Settings - get', async function () {
+    skipIfNoDockerRegistry(providerContext);
+    before(async () => {
+      await esArchiver.load('x-pack/test/functional/es_archives/fleet/empty_fleet_server');
+    });
+    setupFleetAndAgents(providerContext);
+
+    after(async () => {
+      await kibanaServer.savedObjects.cleanStandardList();
+      await esArchiver.unload('x-pack/test/functional/es_archives/fleet/empty_fleet_server');
+    });
+
+    it('should respond with fleet_server_hosts', async function () {
+      // Create a fleet server host
+      await supertest
+        .post(`/api/fleet/fleet_server_hosts`)
+        .set('kbn-xsrf', 'xxxx')
+        .send({
+          id: 'test-default-123',
+          name: 'Default',
+          is_default: true,
+          host_urls: ['https://test.com:8080', 'https://test.com:8081'],
+        })
+        .expect(200);
+
+      // Assert that the hosts appear in the setting response
+      const response = await supertest
+        .get(`/api/fleet/settings`)
+        .set('kbn-xsrf', 'xxxx')
+        .expect(200);
+
+      expect(response.body.item.fleet_server_hosts).to.eql([
+        'https://test.com:8080',
+        'https://test.com:8081',
+      ]);
+    });
+  });
+}

x-pack/test/fleet_api_integration/apis/settings/index.js

@@ -7,6 +7,7 @@
 
 export default function loadTests({ loadTestFile }) {
   describe('Settings Endpoints', () => {
+    loadTestFile(require.resolve('./get'));
     loadTestFile(require.resolve('./update'));
   });
 }

x-pack/test/fleet_api_integration/apis/settings/update.ts

@@ -18,7 +18,8 @@ export default function (providerContext: FtrProviderContext) {
   const esClient = getService('es');
   const esArchiver = getService('esArchiver');
 
-  describe('Settings - update', async function () {
+  // Skipped as the Fleet Server hosts settings values are no longer used as of https://github.com/elastic/kibana/issues/137785
+  describe.skip('Settings - update', async function () {
     skipIfNoDockerRegistry(providerContext);
     before(async () => {
       await esArchiver.load('x-pack/test/functional/es_archives/fleet/empty_fleet_server');