[APM] Api test for feature flags in serverless (#162128)

Closes #159020

---------

Co-authored-by: kibanamachine <[email protected]>
Co-authored-by: Achyut Jhunjhunwala <[email protected]>

x-pack/plugins/apm/server/routes/fleet/route.ts

@@ -111,7 +111,6 @@ const getMigrationCheckRoute = createApmServerRoute({
   options: { tags: ['access:apm'] },
   handler: async (resources): Promise<RunMigrationCheckResponse> => {
     const { core, plugins, context, config, request } = resources;
-
     throwNotFoundIfFleetMigrationNotAvailable(resources.featureFlags);
 
     const { fleet, security } = plugins;

x-pack/test_serverless/api_integration/config.base.ts

@@ -15,7 +15,11 @@ export function createTestConfig(options: CreateTestConfigOptions) {
 
     return {
       ...svlSharedConfig.getAll(),
-      services,
+
+      services: {
+        ...services,
+        ...options.services,
+      },
       kbnTestServer: {
         ...svlSharedConfig.get('kbnTestServer'),
         serverArgs: [

x-pack/test_serverless/api_integration/services/index.ts

@@ -5,6 +5,7 @@
  * 2.0.
  */
 
+import { GenericFtrProviderContext } from '@kbn/test';
 // eslint-disable-next-line @kbn/imports/no_boundary_crossing
 import { services as xpackApiIntegrationServices } from '../../../test/api_integration/services';
 import { services as svlSharedServices } from '../../shared/services';
@@ -17,3 +18,12 @@ export const services = {
 
   svlCommonApi: SvlCommonApiServiceProvider,
 };
+
+export type InheritedFtrProviderContext = GenericFtrProviderContext<typeof services, {}>;
+
+export type InheritedServices = InheritedFtrProviderContext extends GenericFtrProviderContext<
+  infer TServices,
+  {}
+>
+  ? TServices
+  : {};

x-pack/test_serverless/api_integration/test_suites/observability/apm_api_integration/common/apm_api_supertest.ts

@@ -0,0 +1,131 @@
+/*
+ * 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 {
+  ApmUsername,
+  APM_TEST_PASSWORD,
+  // eslint-disable-next-line @kbn/imports/no_boundary_crossing
+} from '@kbn/apm-plugin/server/test_helpers/create_apm_users/authentication';
+import { format, UrlObject } from 'url';
+import supertest from 'supertest';
+import request from 'superagent';
+import type {
+  APIReturnType,
+  APIClientRequestParamsOf,
+} from '@kbn/apm-plugin/public/services/rest/create_call_apm_api';
+import type { APIEndpoint } from '@kbn/apm-plugin/server';
+import { formatRequest } from '@kbn/server-route-repository';
+import { InheritedFtrProviderContext } from '../../../../services';
+
+export function createApmApiClient(st: supertest.SuperTest<supertest.Test>) {
+  return async <TEndpoint extends APIEndpoint>(
+    options: {
+      type?: 'form-data';
+      endpoint: TEndpoint;
+    } & APIClientRequestParamsOf<TEndpoint> & { params?: { query?: { _inspect?: boolean } } }
+  ): Promise<SupertestReturnType<TEndpoint>> => {
+    const { endpoint, type } = options;
+
+    const params = 'params' in options ? (options.params as Record<string, any>) : {};
+
+    const { method, pathname, version } = formatRequest(endpoint, params.path);
+    const url = format({ pathname, query: params?.query });
+
+    const headers: Record<string, string> = { 'kbn-xsrf': 'foo' };
+
+    if (version) {
+      headers['Elastic-Api-Version'] = version;
+    }
+
+    let res: request.Response;
+    if (type === 'form-data') {
+      const fields: Array<[string, any]> = Object.entries(params.body);
+      const formDataRequest = st[method](url)
+        .set(headers)
+        .set('Content-type', 'multipart/form-data');
+
+      for (const field of fields) {
+        formDataRequest.field(field[0], field[1]);
+      }
+
+      res = await formDataRequest;
+    } else if (params.body) {
+      res = await st[method](url).send(params.body).set(headers);
+    } else {
+      res = await st[method](url).set(headers);
+    }
+
+    // supertest doesn't throw on http errors
+    if (res?.status !== 200) {
+      throw new ApmApiError(res, endpoint);
+    }
+
+    return res;
+  };
+}
+
+type ApiErrorResponse = Omit<request.Response, 'body'> & {
+  body: {
+    statusCode: number;
+    error: string;
+    message: string;
+    attributes: object;
+  };
+};
+
+export type ApmApiSupertest = ReturnType<typeof createApmApiClient>;
+
+export class ApmApiError extends Error {
+  res: ApiErrorResponse;
+
+  constructor(res: request.Response, endpoint: string) {
+    super(
+      `Unhandled ApmApiError.
+Status: "${res.status}"
+Endpoint: "${endpoint}"
+Body: ${JSON.stringify(res.body)}`
+    );
+
+    this.res = res;
+  }
+}
+
+async function getApmApiClient({
+  kibanaServer,
+  username,
+}: {
+  kibanaServer: UrlObject;
+  username: ApmUsername | 'elastic';
+}) {
+  const url = format({
+    ...kibanaServer,
+    auth: `${username}:${APM_TEST_PASSWORD}`,
+  });
+
+  return createApmApiClient(supertest(url));
+}
+
+export interface SupertestReturnType<TEndpoint extends APIEndpoint> {
+  status: number;
+  body: APIReturnType<TEndpoint>;
+}
+
+type ApmApiClientKey = 'slsUser';
+export type ApmApiClient = Record<ApmApiClientKey, Awaited<ReturnType<typeof getApmApiClient>>>;
+
+export async function getApmApiClientService({
+  getService,
+}: InheritedFtrProviderContext): Promise<ApmApiClient> {
+  const svlSharedConfig = getService('config');
+  const kibanaServer = svlSharedConfig.get('servers.kibana');
+
+  return {
+    slsUser: await getApmApiClient({
+      kibanaServer,
+      username: 'elastic',
+    }),
+  };
+}

x-pack/test_serverless/api_integration/test_suites/observability/apm_api_integration/common/services.ts

@@ -0,0 +1,25 @@
+/*
+ * 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 { GenericFtrProviderContext } from '@kbn/test';
+import { ApmApiClient, getApmApiClientService } from './apm_api_supertest';
+import {
+  InheritedServices,
+  InheritedFtrProviderContext,
+  services as inheritedServices,
+} from '../../../../services';
+
+export type APMServices = InheritedServices & {
+  apmApiClient: (context: InheritedFtrProviderContext) => Promise<ApmApiClient>;
+};
+
+export const services: APMServices = {
+  ...inheritedServices,
+  apmApiClient: getApmApiClientService,
+};
+
+export type APMFtrContextProvider = GenericFtrProviderContext<typeof services, {}>;