Add foreground service, some cleanup, and start websocket server

src/service/WebsocketServer.ts

@@ -0,0 +1,50 @@
+import {Unit, UnitStatus} from '../lifecycle/Unit'
+import {Inject, Singleton} from '../di'
+import * as WebSocket from 'ws'
+import {HTTPServer} from './HTTPServer'
+import {Logging} from './Logging'
+import {ErrorWithContext} from '../util'
+import {Request} from '../http/lifecycle/Request'
+
+@Singleton()
+export class WebsocketServer extends Unit {
+    @Inject()
+    protected readonly http!: HTTPServer
+
+    @Inject()
+    protected readonly logging!: Logging
+
+    protected server?: WebSocket.Server
+
+    public async up(): Promise<void> {
+        // Make sure the HTTP server is started. Otherwise, this is going to fail anyway
+        if ( this.http.status !== UnitStatus.Started ) {
+            throw new ErrorWithContext('Cannot start WebsocketServer without HTTPServer.', {
+                suggestion: 'Make sure the HTTPServer is registered in your Units.extollo.ts file, and it is listed before the WebsocketServer.',
+            })
+        }
+
+        // Start the websocket server
+        this.logging.info('Starting WebSocket server...')
+        this.server = new WebSocket.Server<WebSocket.WebSocket>({
+            server: this.http.getServer(),
+        })
+
+        // Register the websocket handler
+        this.server.on('connection', (ws, request) => {
+            this.logging.info('Got WebSocket connection! ' + request.method)
+            const extolloReq = new Request(request)
+            this.logging.debug(ws)
+            this.logging.debug(request)
+        })
+    }
+
+    public down(): Promise<void> {
+        return new Promise(res => {
+            // Stop the websocket server, if it exists
+            if ( this.server ) {
+                this.server.close(() => res())
+            }
+        })
+    }
+}