Introduce LegacyAppender that forwards log records to the legacy platform.

platform/legacy/LegacyKbnServer.ts

@@ -1,22 +1,25 @@
-import { LegacyConfig } from './LegacyPlatformConfig';
-import { LegacyPlatformProxifier } from './LegacyPlatformProxifier';
-
 /**
- * Represents legacy kbnServer instance, provided by the legacy platform.
+ * Represents a wrapper around legacy `kbnServer` instance that exposes only
+ * a subset of `kbnServer` APIs used by the new platform.
  * @internal
  */
-export interface LegacyKbnServer {
-  readonly config: LegacyConfig;
-  readonly server: { log: (...args: any[]) => void };
+export class LegacyKbnServer {
+  constructor(private readonly rawKbnServer: any) {}
 
   /**
-   * Custom HTTP Listener provided by the new platform and that will be used
-   * within legacy platform by HapiJS server.
+   * Custom HTTP Listener used by HapiJS server in the legacy platform.
    */
-  newPlatformProxyListener: LegacyPlatformProxifier;
+  get newPlatformProxyListener() {
+    return this.rawKbnServer.newPlatform.proxyListener;
+  }
 
   /**
-   * Propagates legacy config updates to the new platform.
+   * Forwards log request to the legacy platform.
+   * @param tags A string or array of strings used to briefly identify the event.
+   * @param [data] Optional string or object to log with the event.
+   * @param [timestamp] Timestamp value associated with the log record.
    */
-  updateNewPlatformConfig: (legacyConfig: LegacyConfig) => void;
+  log(tags: string | string[], data?: string | Error, timestamp?: Date) {
+    this.rawKbnServer.server.log(tags, data, timestamp);
+  }
 }

platform/legacy/__tests__/LegacyKbnServer.test.ts

@@ -0,0 +1,28 @@
+import { LegacyKbnServer } from '..';
+
+it('correctly returns `newPlatformProxyListener`.', () => {
+  const rawKbnServer = {
+    newPlatform: {
+      proxyListener: {}
+    }
+  };
+
+  const legacyKbnServer = new LegacyKbnServer(rawKbnServer);
+  expect(legacyKbnServer.newPlatformProxyListener).toBe(
+    rawKbnServer.newPlatform.proxyListener
+  );
+});
+
+it('correctly forwards log record.', () => {
+  const rawKbnServer = {
+    server: { log: jest.fn() }
+  };
+
+  const legacyKbnServer = new LegacyKbnServer(rawKbnServer);
+
+  const timestamp = new Date(Date.UTC(2012, 1, 1, 11, 22, 33, 44));
+  legacyKbnServer.log(['one', 'two'], 'message', timestamp);
+  legacyKbnServer.log('three', new Error('log error'), timestamp);
+
+  expect(rawKbnServer.server.log.mock.calls).toMatchSnapshot();
+});

platform/legacy/__tests__/__snapshots__/LegacyKbnServer.test.ts.snap

@@ -0,0 +1,19 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`correctly forwards log record. 1`] = `
+Array [
+  Array [
+    Array [
+      "one",
+      "two",
+    ],
+    "message",
+    2012-02-01T11:22:33.044Z,
+  ],
+  Array [
+    "three",
+    [Error: log error],
+    2012-02-01T11:22:33.044Z,
+  ],
+]
+`;

platform/legacy/index.ts

@@ -21,17 +21,24 @@ import {
 /**
  * @internal
  */
-export const injectIntoKbnServer = (kbnServer: LegacyKbnServer) => {
-  const legacyConfig$ = new BehaviorSubject(kbnServer.config);
+export const injectIntoKbnServer = (rawKbnServer: any) => {
+  const legacyConfig$ = new BehaviorSubject(rawKbnServer.config);
   const config$ = legacyConfig$.map(
     legacyConfig => new LegacyConfigToRawConfigAdapter(legacyConfig)
   );
 
-  kbnServer.updateNewPlatformConfig = (legacyConfig: LegacyConfig) => {
-    legacyConfig$.next(legacyConfig);
-  };
+  rawKbnServer.newPlatform = {
+    // Custom HTTP Listener that will be used within legacy platform by HapiJS server.
+    proxyListener: new LegacyPlatformProxifier(
+      new Root(
+        config$,
+        Env.createDefault({ kbnServer: new LegacyKbnServer(rawKbnServer) })
+      )
+    ),
 
-  kbnServer.newPlatformProxyListener = new LegacyPlatformProxifier(
-    new Root(config$, Env.createDefault({ kbnServer }))
-  );
+    // Propagates legacy config updates to the new platform.
+    updateConfig(legacyConfig: LegacyConfig) {
+      legacyConfig$.next(legacyConfig);
+    }
+  };
 };

platform/legacy/logging/appenders/LegacyAppender.ts

@@ -28,7 +28,7 @@ export class LegacyAppender implements DisposableAppender {
    * @param record `LogRecord` instance to forward to.
    */
   append(record: LogRecord) {
-    this.kbnServer.server.log(
+    this.kbnServer.log(
       [record.level.id.toLowerCase(), ...record.context.split('.')],
       record.error || record.message,
       record.timestamp

platform/legacy/logging/appenders/__tests__/LegacyAppender.test.ts

@@ -1,6 +1,7 @@
 import * as mockSchema from '../../../../lib/schema';
 import { LogLevel } from '../../../../logging/LogLevel';
 import { LogRecord } from '../../../../logging/LogRecord';
+import { LegacyKbnServer } from '../../../LegacyKbnServer';
 import { LegacyAppender } from '../LegacyAppender';
 
 test('`createConfigSchema()` creates correct schema.', () => {
@@ -69,14 +70,14 @@ test('`append()` correctly pushes records to legacy platform.', () => {
     }
   ];
 
-  const legacyLogStub = jest.fn();
-  const appender = new LegacyAppender(
-    { server: { log: legacyLogStub } } as any
-  );
+  const rawKbnServerMock = {
+    server: { log: jest.fn() }
+  };
+  const appender = new LegacyAppender(new LegacyKbnServer(rawKbnServerMock));
 
   for (const record of records) {
     appender.append(record);
   }
 
-  expect(legacyLogStub.mock.calls).toMatchSnapshot();
+  expect(rawKbnServerMock.server.log.mock.calls).toMatchSnapshot();
 });

src/cli/serve/serve.js

@@ -181,8 +181,8 @@ export default function (program) {
       kbnServer.server.log(['info', 'config'], 'Reloaded logging configuration due to SIGHUP.');
 
       // If new platform config subscription is active, let's notify it with the updated config.
-      if (kbnServer.updateNewPlatformConfig) {
-        kbnServer.updateNewPlatformConfig(config);
+      if (kbnServer.newPlatform) {
+        kbnServer.newPlatform.updateConfig(config);
       }
     });
 

src/server/http/setup_connection.js

@@ -3,7 +3,8 @@ import { map } from 'lodash';
 import secureOptions from './secure_options';
 
 export default function (kbnServer, server, config) {
-  const newPlatformProxyListener = kbnServer && kbnServer.newPlatformProxyListener;
+  const newPlatformProxyListener = kbnServer && kbnServer.newPlatform
+    && kbnServer.newPlatform.proxyListener;
 
   // this mixin is used outside of the kbn server, so it MUST work without a full kbnServer object.
   kbnServer = null;