UDS/TCP options

Summary:
Provide an option to enable/disable TCP connections on flipper-server.

The only change at this stage is that Flipper Desktop will use UDS to connect to flipper-server.

Reviewed By: passy

Differential Revision: D37519656

fbshipit-source-id: 3d02084666fde532ec76134edf8cf6a231060a48

desktop/flipper-server-core/src/server/startServer.tsx

@@ -13,7 +13,7 @@ import express, {Express} from 'express';
 import http, {ServerResponse} from 'http';
 import path from 'path';
 import fs from 'fs-extra';
-import {VerifyClientCallbackSync, WebSocketServer} from 'ws';
+import {ServerOptions, VerifyClientCallbackSync, WebSocketServer} from 'ws';
 import {WEBSOCKET_MAX_MESSAGE_SIZE} from '../comms/ServerWebSocket';
 import {parse} from 'url';
 import {makeSocketPath, checkSocketInUse} from './utilities';
@@ -28,6 +28,7 @@ type Config = {
   port: number;
   staticDir: string;
   entry: string;
+  tcp: boolean;
 };
 
 type ReadyForConnections = (
@@ -108,6 +109,12 @@ async function startProxyServer(
   // On Windows, a proxy is not created and the server starts
   // listening at the specified port.
   if (os.platform() === 'win32') {
+    if (!config.tcp) {
+      console.error(
+        'No port was supplied and domain socket access is not available for non-POSIX systems, unable to start server',
+      );
+      process.exit(1);
+    }
     return new Promise((resolve) => {
       console.log(`Starting server on http://localhost:${config.port}`);
       const readyForIncomingConnections = (): Promise<void> => {
@@ -129,17 +136,22 @@ async function startProxyServer(
     await fs.rm(socketPath, {force: true});
   }
 
-  const proxyServer = proxy.createProxyServer({
-    target: {host: 'localhost', port: 0, socketPath},
-    autoRewrite: true,
-    ws: true,
-  });
+  const proxyServer: proxy | undefined = config.tcp
+    ? proxy.createProxyServer({
+        target: {host: 'localhost', port: 0, socketPath},
+        autoRewrite: true,
+        ws: true,
+      })
+    : undefined;
+
   console.log('Starting socket server on ', socketPath);
-  console.log(`Starting proxy server on http://localhost:${config.port}`);
+  if (proxyServer) {
+    console.log(`Starting proxy server on http://localhost:${config.port}`);
+  }
 
   exitHook(() => {
     console.log('Shutdown server');
-    proxyServer.close();
+    proxyServer?.close();
     server.close();
 
     console.log('Cleaning up socket on exit:', socketPath);
@@ -148,7 +160,7 @@ async function startProxyServer(
     fs.rmSync(socketPath, {force: true});
   });
 
-  proxyServer.on('error', (err, _req, res) => {
+  proxyServer?.on('error', (err, _req, res) => {
     console.warn('Error in proxy server:', err);
     if (res instanceof ServerResponse) {
       res.writeHead(502, 'Failed to proxy request');
@@ -163,7 +175,7 @@ async function startProxyServer(
     ): Promise<void> => {
       attachSocketServer(socket, serverImpl, companionEnv);
       return new Promise((resolve) => {
-        proxyServer.listen(config.port);
+        proxyServer?.listen(config.port);
         server.listen(socketPath, undefined, () => resolve());
       });
     };
@@ -222,12 +234,15 @@ function addWebsocket(server: http.Server, config: Config) {
     }
   };
 
-  const wss = new WebSocketServer({
+  const options: ServerOptions = {
     noServer: true,
     maxPayload: WEBSOCKET_MAX_MESSAGE_SIZE,
-    verifyClient,
-  });
+  };
+  if (config.tcp) {
+    options.verifyClient = verifyClient;
+  }
 
+  const wss = new WebSocketServer(options);
   server.on('upgrade', function upgrade(request, socket, head) {
     const {pathname} = parse(request.url!);