add option to listen on unix domain socket

This adds a CLI argument --socket, that takes a path.
The server will bind this path instead of a TCP port.

closes gitpod-io#144

Author: leifwalsh

src/vs/server/node/server.main.ts

@@ -302,11 +302,13 @@ async function handleFetchCallback(req: http.IncomingMessage, res: http.ServerRe
 interface ServerParsedArgs extends NativeParsedArgs {
 	port?: string
 	host?: string
+	socket?: string
 }
 const SERVER_OPTIONS: OptionDescriptions<ServerParsedArgs> = {
 	...OPTIONS,
 	port: { type: 'string' },
-	host: { type: 'string' }
+	host: { type: 'string' },
+	socket: { type: 'string' }
 };
 
 export interface IStartServerResult {
@@ -1008,25 +1010,30 @@ export async function main(options: IServerOptions): Promise<void> {
 			});
 		});
 
-		let port = 3000;
-		if (parsedArgs.port) {
-			port = Number(parsedArgs.port);
-		} else if (typeof options.port === 'number') {
-			port = options.port;
-		}
-
-		const host = parsedArgs.host || '0.0.0.0';
-		server.on('error', () => {
-			server.close();
-			process.exit(1);
-		});
-
-		server.listen(port, host, () => {
+		const listeningListener = () => {
 			const addressInfo = server.address() as net.AddressInfo;
 			const address = addressInfo.address === '0.0.0.0' || addressInfo.address === '127.0.0.1' ? 'localhost' : addressInfo.address;
 			const formattedPort = addressInfo.port === 80 ? '' : String(addressInfo.port);
 			logService.info(`Web UI available at http://${address}:${formattedPort}`);
-		});
+		};
+
+		if (parsedArgs.socket) {
+			server.listen(parsedArgs.socket, listeningListener);
+		} else {
+			let port = 3000;
+			if (parsedArgs.port) {
+				port = Number(parsedArgs.port);
+			} else if (typeof options.port === 'number') {
+				port = options.port;
+			}
+
+			const host = parsedArgs.host || '0.0.0.0';
+			server.on('error', () => {
+				server.close();
+				process.exit(1);
+			});
+			server.listen(port, host, listeningListener);
+		}
 
 	});
 }