use sync getter for config on client side instead of observable

src/core/MIGRATION.md

@@ -1261,23 +1261,21 @@ export const config: PluginConfigDescriptor<ConfigType> = {
   exposeToBrowser: ['uiProp'],
   schema: configSchema,
 };
-
-export type ClientConfigType = Pick<ConfigType, 'uiProp'>
 ```
 
-Configuration containing only the exposed properties will be then available on the client-side plugin using the same API as the server-side:
+Configuration containing only the exposed properties will be then available on the client-side using the plugin's `initializerContext`:
 ```typescript
 // my_plugin/public/index.ts
-import { ClientConfigType } from '../server';
+interface ClientConfigType {
+  uiProp: string;
+}
 
 export class Plugin implements Plugin<PluginSetup, PluginStart> {
   constructor(private readonly initializerContext: PluginInitializerContext) {}
 
   public async setup(core: CoreSetup, deps: {}) {
-    const config = await this.initializerContext.config
-      .create<ClientConfigType>()
-      .pipe(take(1))
-      .toPromise();
+    const config = this.initializerContext.config.get<ClientConfigType>();
+    // ...
   }
 ```
 

src/core/public/mocks.ts

@@ -16,7 +16,6 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-import { of } from 'rxjs';
 import { applicationServiceMock } from './application/application_service.mock';
 import { chromeServiceMock } from './chrome/chrome_service.mock';
 import { CoreContext, CoreSetup, CoreStart, PluginInitializerContext, NotificationsSetup } from '.';
@@ -94,7 +93,7 @@ function pluginInitializerContextMock() {
       },
     },
     config: {
-      create: <T>() => of({} as T),
+      get: <T>() => ({} as T),
     },
   };
 

src/core/public/plugins/plugin_context.ts

@@ -18,7 +18,6 @@
  */
 
 import { omit } from 'lodash';
-import { Observable, of } from 'rxjs';
 import { DiscoveredPlugin } from '../../server';
 import { PluginOpaqueId, PackageInfo, EnvironmentMode } from '../../server/types';
 import { CoreContext } from '../core_system';
@@ -41,7 +40,7 @@ export interface PluginInitializerContext<ConfigSchema = unknown> {
     packageInfo: Readonly<PackageInfo>;
   };
   readonly config: {
-    create: <T = ConfigSchema>() => Observable<T>;
+    get: <T = ConfigSchema>() => T;
   };
 }
 
@@ -67,8 +66,8 @@ export function createPluginInitializerContext(
     opaqueId,
     env: coreContext.env,
     config: {
-      create<T>() {
-        return of<T>((pluginConfig as unknown) as T);
+      get<T>() {
+        return (pluginConfig as unknown) as T;
       },
     },
   };

src/core/public/plugins/plugins_service.test.ts

@@ -46,7 +46,6 @@ import { CoreSetup, CoreStart, PluginInitializerContext } from '..';
 import { docLinksServiceMock } from '../doc_links/doc_links_service.mock';
 import { savedObjectsMock } from '../saved_objects/saved_objects_service.mock';
 import { contextServiceMock } from '../context/context_service.mock';
-import { take } from 'rxjs/operators';
 
 export let mockPluginInitializers: Map<PluginName, MockedPluginInitializer>;
 
@@ -229,10 +228,7 @@ describe('PluginsService', () => {
 
       const initializerContext = mockPluginInitializers.get('pluginA')!.mock
         .calls[0][0] as PluginInitializerContext;
-      const config = await initializerContext.config
-        .create()
-        .pipe(take(1))
-        .toPromise();
+      const config = initializerContext.config.get();
       expect(config).toMatchObject(pluginConfig);
     });
 

src/plugins/testbed/public/plugin.ts

@@ -17,7 +17,6 @@
  * under the License.
  */
 
-import { take } from 'rxjs/operators';
 import { Plugin, CoreSetup, PluginInitializerContext } from 'kibana/public';
 
 interface ConfigType {
@@ -28,10 +27,7 @@ export class TestbedPlugin implements Plugin<TestbedPluginSetup, TestbedPluginSt
   constructor(private readonly initializerContext: PluginInitializerContext) {}
 
   public async setup(core: CoreSetup, deps: {}) {
-    const config = await this.initializerContext.config
-      .create<ConfigType>()
-      .pipe(take(1))
-      .toPromise();
+    const config = this.initializerContext.config.get<ConfigType>();
 
     // eslint-disable-next-line no-console
     console.log(`Testbed plugin set up. uiProp: '${config.uiProp}'`);

x-pack/legacy/plugins/siem/public/apps/index.ts

@@ -4,13 +4,12 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { of } from 'rxjs';
 import chrome from 'ui/chrome';
 import { npStart } from 'ui/new_platform';
 import { Plugin } from './plugin';
 
 new Plugin(
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  { opaqueId: Symbol('siem'), env: {} as any, config: { create: () => of({} as any) } },
+  { opaqueId: Symbol('siem'), env: {} as any, config: { get: () => ({} as any) } },
   chrome
 ).start(npStart.core, npStart.plugins);

x-pack/legacy/plugins/uptime/public/apps/index.ts

@@ -4,12 +4,11 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-import { of } from 'rxjs';
 import chrome from 'ui/chrome';
 import { npStart } from 'ui/new_platform';
 import { Plugin } from './plugin';
 
 new Plugin(
-  { opaqueId: Symbol('uptime'), env: {} as any, config: { create: () => of({} as any) } },
+  { opaqueId: Symbol('uptime'), env: {} as any, config: { get: () => ({} as any) } },
   chrome
 ).start(npStart);