chore: extract UI config logic into its own service (#10704)

https://linear.app/unleash/issue/2-3921/extract-ui-config-logic-into-its-own-service

Extracts UI config logic into its own service.

This is the first step to accomplish resource limits and license key
resources alignment.

src/lib/routes/admin-api/index.ts

@@ -8,7 +8,7 @@ import EventController from './event.js';
 import PlaygroundController from '../../features/playground/playground.js';
 import MetricsController from './metrics.js';
 import UserController from './user/user.js';
-import ConfigController from './config.js';
+import UiConfigController from '../../ui-config/ui-config-controller.js';
 import { ContextController } from '../../features/context/context.js';
 import ClientMetricsController from '../../features/metrics/client-metrics/client-metrics.js';
 import TagController from './tag.js';
@@ -90,7 +90,7 @@ export class AdminApi extends Controller {
 
         this.app.use(
             '/ui-config',
-            new ConfigController(config, services).router,
+            new UiConfigController(config, services).router,
         );
         this.app.use(
             '/context',

src/lib/services/index.ts

@@ -170,6 +170,7 @@ import type { IPrivateProjectChecker } from '../features/private-project/private
 import { UnknownFlagsService } from '../features/metrics/unknown-flags/unknown-flags-service.js';
 import type FeatureLinkService from '../features/feature-links/feature-link-service.js';
 import { createUserService } from '../features/users/createUserService.js';
+import { UiConfigService } from '../ui-config/ui-config-service.js';
 
 export const createServices = (
     stores: IUnleashStores,
@@ -441,6 +442,15 @@ export const createServices = (
         ? withTransactional(createUserSubscriptionsService(config), db)
         : withFakeTransactional(createFakeUserSubscriptionsService(config));
 
+    const uiConfigService = new UiConfigService(config, {
+        versionService,
+        settingService,
+        emailService,
+        frontendApiService,
+        maintenanceService,
+        sessionService,
+    });
+
     return {
         transactionalAccessService,
         accessService,
@@ -514,6 +524,7 @@ export const createServices = (
         transactionalFeatureLinkService,
         featureLinkService,
         unknownFlagsService,
+        uiConfigService,
     };
 };
 
@@ -645,4 +656,5 @@ export interface IUnleashServices {
     transactionalFeatureLinkService: WithTransactional<FeatureLinkService>;
     featureLinkService: FeatureLinkService;
     unknownFlagsService: UnknownFlagsService;
+    uiConfigService: UiConfigService;
 }

src/lib/types/experimental.ts

@@ -59,7 +59,8 @@ export type IFlagKey =
     | 'fetchMode'
     | 'optimizeLifecycle'
     | 'newStrategyModal'
-    | 'globalChangeRequestList';
+    | 'globalChangeRequestList'
+    | 'newUiConfigService';
 
 export type IFlags = Partial<{ [key in IFlagKey]: boolean | Variant }>;
 
@@ -273,6 +274,10 @@ const flags: IFlags = {
         process.env.UNLEASH_EXPERIMENTAL_GLOBAL_CHANGE_REQUEST_LIST,
         false,
     ),
+    newUiConfigService: parseEnvVarBoolean(
+        process.env.UNLEASH_EXPERIMENTAL_NEW_UI_CONFIG_SERVICE,
+        false,
+    ),
 };
 
 export const defaultExperimentalOptions: IExperimentalOptions = {

src/lib/ui-config/ui-config-controller.ts

@@ -1,37 +1,34 @@
 import type { Response } from 'express';
-import type { AuthedRequest } from '../../types/core.js';
-import type { IUnleashServices } from '../../services/index.js';
-import { IAuthType, type IUnleashConfig } from '../../types/option.js';
-import version from '../../util/version.js';
-import Controller from '../controller.js';
-import type VersionService from '../../services/version-service.js';
-import type SettingService from '../../services/setting-service.js';
+import type { AuthedRequest } from '../types/core.js';
+import type { IUnleashServices } from '../services/index.js';
+import { IAuthType, type IUnleashConfig } from '../types/option.js';
+import version from '../util/version.js';
+import Controller from '../routes/controller.js';
+import type VersionService from '../services/version-service.js';
+import type SettingService from '../services/setting-service.js';
 import {
     type SimpleAuthSettings,
     simpleAuthSettingsKey,
-} from '../../types/settings/simple-auth-settings.js';
-import { ADMIN, NONE, UPDATE_CORS } from '../../types/permissions.js';
-import { createResponseSchema } from '../../openapi/util/create-response-schema.js';
+} from '../types/settings/simple-auth-settings.js';
+import { ADMIN, NONE, UPDATE_CORS } from '../types/permissions.js';
+import { createResponseSchema } from '../openapi/util/create-response-schema.js';
 import {
     uiConfigSchema,
     type UiConfigSchema,
-} from '../../openapi/spec/ui-config-schema.js';
-import type { OpenApiService } from '../../services/openapi-service.js';
-import type { EmailService } from '../../services/email-service.js';
-import { emptyResponse } from '../../openapi/util/standard-responses.js';
-import type { IAuthRequest } from '../unleash-types.js';
-import NotFoundError from '../../error/notfound-error.js';
-import type { SetCorsSchema } from '../../openapi/spec/set-cors-schema.js';
-import { createRequestSchema } from '../../openapi/util/create-request-schema.js';
-import type {
-    FrontendApiService,
-    SessionService,
-} from '../../services/index.js';
-import type MaintenanceService from '../../features/maintenance/maintenance-service.js';
-import type ClientInstanceService from '../../features/metrics/instance/instance-service.js';
-import type { IFlagResolver } from '../../types/index.js';
+} from '../openapi/spec/ui-config-schema.js';
+import type { OpenApiService } from '../services/openapi-service.js';
+import type { EmailService } from '../services/email-service.js';
+import { emptyResponse } from '../openapi/util/standard-responses.js';
+import type { IAuthRequest } from '../routes/unleash-types.js';
+import NotFoundError from '../error/notfound-error.js';
+import type { SetCorsSchema } from '../openapi/spec/set-cors-schema.js';
+import { createRequestSchema } from '../openapi/util/create-request-schema.js';
+import type { FrontendApiService, SessionService } from '../services/index.js';
+import type MaintenanceService from '../features/maintenance/maintenance-service.js';
+import type { IFlagResolver } from '../types/index.js';
+import type { UiConfigService } from './ui-config-service.js';
 
-class ConfigController extends Controller {
+class UiConfigController extends Controller {
     private versionService: VersionService;
 
     private settingService: SettingService;
@@ -40,14 +37,14 @@ class ConfigController extends Controller {
 
     private emailService: EmailService;
 
-    private clientInstanceService: ClientInstanceService;
-
     private sessionService: SessionService;
 
     private maintenanceService: MaintenanceService;
 
     private flagResolver: IFlagResolver;
 
+    private uiConfigService: UiConfigService;
+
     private readonly openApiService: OpenApiService;
 
     constructor(
@@ -59,8 +56,8 @@ class ConfigController extends Controller {
             openApiService,
             frontendApiService,
             maintenanceService,
-            clientInstanceService,
             sessionService,
+            uiConfigService,
         }: Pick<
             IUnleashServices,
             | 'versionService'
@@ -71,18 +68,20 @@ class ConfigController extends Controller {
             | 'maintenanceService'
             | 'clientInstanceService'
             | 'sessionService'
+            | 'uiConfigService'
         >,
     ) {
         super(config);
+        this.flagResolver = config.flagResolver;
+        this.openApiService = openApiService;
+        this.uiConfigService = uiConfigService;
         this.versionService = versionService;
         this.settingService = settingService;
         this.emailService = emailService;
-        this.openApiService = openApiService;
         this.frontendApiService = frontendApiService;
         this.maintenanceService = maintenanceService;
-        this.clientInstanceService = clientInstanceService;
         this.sessionService = sessionService;
-        this.flagResolver = config.flagResolver;
+
         this.route({
             method: 'get',
             path: '',
@@ -125,6 +124,17 @@ class ConfigController extends Controller {
         req: AuthedRequest,
         res: Response<UiConfigSchema>,
     ): Promise<void> {
+        if (this.flagResolver.isEnabled('newUiConfigService')) {
+            const uiConfig = await this.uiConfigService.getUiConfig(req.user);
+
+            return this.openApiService.respondWithValidation(
+                200,
+                res,
+                uiConfigSchema.$id,
+                uiConfig,
+            );
+        }
+
         const getMaxSessionsCount = async () => {
             if (this.flagResolver.isEnabled('showUserDeviceCount')) {
                 return this.sessionService.getMaxSessionsCount();
@@ -207,4 +217,4 @@ class ConfigController extends Controller {
     }
 }
 
-export default ConfigController;
+export default UiConfigController;

src/lib/ui-config/ui-config-service.ts

@@ -0,0 +1,127 @@
+import type { IUnleashConfig } from '../types/option.js';
+import type { UiConfigSchema } from '../openapi/index.js';
+import {
+    IAuthType,
+    type EmailService,
+    type FrontendApiService,
+    type IFlagResolver,
+    type IUnleashServices,
+    type SessionService,
+    type SettingService,
+    type User,
+    type VersionService,
+} from '../server-impl.js';
+import type MaintenanceService from '../features/maintenance/maintenance-service.js';
+import {
+    type SimpleAuthSettings,
+    simpleAuthSettingsKey,
+} from '../types/settings/simple-auth-settings.js';
+import version from '../util/version.js';
+
+export class UiConfigService {
+    private config: IUnleashConfig;
+
+    private versionService: VersionService;
+
+    private settingService: SettingService;
+
+    private frontendApiService: FrontendApiService;
+
+    private emailService: EmailService;
+
+    private sessionService: SessionService;
+
+    private maintenanceService: MaintenanceService;
+
+    private flagResolver: IFlagResolver;
+
+    constructor(
+        config: IUnleashConfig,
+        {
+            versionService,
+            settingService,
+            emailService,
+            frontendApiService,
+            maintenanceService,
+            sessionService,
+        }: Pick<
+            IUnleashServices,
+            | 'versionService'
+            | 'settingService'
+            | 'emailService'
+            | 'frontendApiService'
+            | 'maintenanceService'
+            | 'sessionService'
+        >,
+    ) {
+        this.config = config;
+        this.flagResolver = config.flagResolver;
+        this.versionService = versionService;
+        this.settingService = settingService;
+        this.emailService = emailService;
+        this.frontendApiService = frontendApiService;
+        this.maintenanceService = maintenanceService;
+        this.sessionService = sessionService;
+    }
+
+    async getMaxSessionsCount(): Promise<number> {
+        if (this.flagResolver.isEnabled('showUserDeviceCount')) {
+            return this.sessionService.getMaxSessionsCount();
+        }
+        return 0;
+    }
+
+    async getUiConfig(user: User): Promise<UiConfigSchema> {
+        const [
+            frontendSettings,
+            simpleAuthSettings,
+            maintenanceMode,
+            maxSessionsCount,
+        ] = await Promise.all([
+            this.frontendApiService.getFrontendSettings(false),
+            this.settingService.get<SimpleAuthSettings>(simpleAuthSettingsKey),
+            this.maintenanceService.isMaintenanceMode(),
+            this.getMaxSessionsCount(),
+        ]);
+
+        const disablePasswordAuth =
+            simpleAuthSettings?.disabled ||
+            this.config.authentication.type === IAuthType.NONE;
+
+        const expFlags = this.config.flagResolver.getAll({
+            email: user.email,
+        });
+
+        const flags = {
+            ...this.config.ui.flags,
+            ...expFlags,
+        };
+
+        const unleashContext = {
+            ...this.flagResolver.getStaticContext(),
+            email: user.email,
+            userId: user.id,
+        };
+
+        const uiConfig: UiConfigSchema = {
+            ...this.config.ui,
+            flags,
+            version,
+            emailEnabled: this.emailService.isEnabled(),
+            unleashUrl: this.config.server.unleashUrl,
+            baseUriPath: this.config.server.baseUriPath,
+            authenticationType: this.config.authentication?.type,
+            frontendApiOrigins: frontendSettings.frontendApiOrigins,
+            versionInfo: await this.versionService.getVersionInfo(),
+            prometheusAPIAvailable: this.config.prometheusApi !== undefined,
+            resourceLimits: this.config.resourceLimits,
+            disablePasswordAuth,
+            maintenanceMode,
+            feedbackUriPath: this.config.feedbackUriPath,
+            maxSessionsCount,
+            unleashContext: unleashContext,
+        };
+
+        return uiConfig;
+    }
+}

src/lib/ui-config/ui-config.test.ts

@@ -1,15 +1,15 @@
 import supertest, { type Test } from 'supertest';
-import { createTestConfig } from '../../../test/config/test-config.js';
+import { createTestConfig } from '../../test/config/test-config.js';
 
-import createStores from '../../../test/fixtures/store.js';
-import getApp from '../../app.js';
-import { createServices } from '../../services/index.js';
+import createStores from '../../test/fixtures/store.js';
+import getApp from '../app.js';
+import { createServices } from '../services/index.js';
 import {
     DEFAULT_SEGMENT_VALUES_LIMIT,
     DEFAULT_STRATEGY_SEGMENTS_LIMIT,
-} from '../../util/segments.js';
+} from '../util/segments.js';
 import type TestAgent from 'supertest/lib/agent.d.ts';
-import type { IUnleashStores } from '../../types/index.js';
+import type { IUnleashStores } from '../types/index.js';
 
 const uiConfig = {
     headerBackground: 'red',

src/server-dev.ts

@@ -55,6 +55,7 @@ process.nextTick(async () => {
                         lifecycleGraphs: true,
                         newStrategyModal: true,
                         globalChangeRequestList: true,
+                        newUiConfigService: true,
                     },
                 },
                 authentication: {