Remove UDS and thus the need for a proxy server

Summary: This change removes the UDS support and thus the need for having a proxy server.

Reviewed By: antonk52

Differential Revision: D48265244

fbshipit-source-id: c76bb4afba63959ddd17901b3887aa278b000beb

desktop/app/src/init.tsx

@@ -47,7 +47,6 @@ import path from 'path';
 import fs from 'fs-extra';
 import os from 'os';
 import {ElectronIpcClientRenderer} from './electronIpc';
-import {checkSocketInUse, makeSocketPath} from 'flipper-server-core';
 import {KeytarModule} from 'flipper-server-core/src/utils/keytar';
 import {initCompanionEnv} from 'flipper-server-companion';
 import ReconnectingWebSocket from 'reconnecting-websocket';
@@ -118,8 +117,6 @@ async function getFlipperServer(
 
   const serverUsageEnabled = gatekeepers['flipper_desktop_use_server'];
   const settings = await loadSettings();
-
-  const socketPath = await makeSocketPath();
   const port = 52342;
   /**
    * Only attempt to use the auth token if one is available. Otherwise,
@@ -134,7 +131,6 @@ async function getFlipperServer(
   // check first with the actual TCP socket
   const searchParams = new URLSearchParams(token ? {token} : {});
   const TCPconnectionURL = new URL(`ws://localhost:${port}?${searchParams}`);
-  const UDSconnectionURL = new URL(`ws+unix://${socketPath}`);
 
   /**
    * Attempt to shutdown a running instance of Flipper server.
@@ -159,12 +155,7 @@ async function getFlipperServer(
    */
   if (await checkPortInUse(port)) {
     console.warn(`[flipper-server] TCP port ${port} is already in use.`);
-
     await shutdown(TCPconnectionURL);
-  } else if (await checkSocketInUse(socketPath)) {
-    console.warn(`[flipper-server] UDS socket is already in use.`);
-
-    await shutdown(UDSconnectionURL);
   }
 
   const [homePath, tempPath, desktopPath] = await Promise.all([
@@ -223,9 +214,7 @@ async function getFlipperServer(
     await server.connect();
     await readyForIncomingConnections(server, companionEnv);
 
-    return getExternalServer(
+    return getExternalServer(TCPconnectionURL);
-      os.platform() === 'win32' ? TCPconnectionURL : UDSconnectionURL,
-    );
   }
   return getEmbeddedServer();
 }

desktop/flipper-server-core/package.json

@@ -25,7 +25,6 @@
     "flipper-server-companion": "0.0.0",
     "form-data": "^4.0.0",
     "fs-extra": "^11.1.0",
-    "http-proxy": "^1.18.1",
     "invariant": "^2.2.4",
     "js-base64": "^3.7.5",
     "jsonwebtoken": "^9.0.0",
@@ -52,7 +51,6 @@
   "devDependencies": {
     "@types/archiver": "^5.3.1",
     "@types/express": "^4.17.13",
-    "@types/http-proxy": "^1.17.8",
     "@types/invariant": "^2.2.35",
     "@types/jsonwebtoken": "^9.0.1",
     "@types/memorystream": "^0.3.0",

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

@@ -7,18 +7,13 @@
  * @format
  */
 
-import os from 'os';
-
 import express, {Express} from 'express';
-import http, {ServerResponse} from 'http';
+import http from 'http';
 import path from 'path';
 import fs from 'fs-extra';
 import {ServerOptions, VerifyClientCallbackSync, WebSocketServer} from 'ws';
 import {WEBSOCKET_MAX_MESSAGE_SIZE} from '../app-connectivity/ServerWebSocket';
 import {parse} from 'url';
-import {makeSocketPath, checkSocketInUse} from './utilities';
-
-import proxy from 'http-proxy';
 import exitHook from 'exit-hook';
 import {attachSocketServer} from './attachSocketServer';
 import {FlipperServerImpl} from '../FlipperServerImpl';
@@ -124,102 +119,23 @@ async function startHTTPServer(config: Config): Promise<{
 
   app.use(express.static(config.staticPath));
 
-  return startProxyServer(config, app);
-}
-
-/**
- * Creates and starts the HTTP and proxy servers.
- * @param config Server configuration.
- * @param app Express app.
- * @returns Returns both the app and server configured and
- * listening.
- */
-async function startProxyServer(
-  config: Config,
-  app: Express,
-): Promise<{
-  app: Express;
-  server: http.Server;
-  socket: WebSocketServer;
-  readyForIncomingConnections: ReadyForConnections;
-}> {
   const server = http.createServer(app);
-  const socket = addWebsocket(server, config);
+  const socket = attachWS(server, config);
-
-  // For now, we only support domain socket access on POSIX-like systems.
-  // On Windows, a proxy is not created and the server starts
-  // listening at the specified port.
-  if (os.platform() === 'win32') {
-    return new Promise((resolve) => {
-      console.log(`Starting server on http://localhost:${config.port}`);
-      const readyForIncomingConnections = (
-        serverImpl: FlipperServerImpl,
-        companionEnv: FlipperServerCompanionEnv,
-      ): Promise<void> => {
-        attachSocketServer(socket, serverImpl, companionEnv);
-        return new Promise((resolve) => {
-          server.listen(config.port, undefined, () => resolve());
-        });
-      };
-      resolve({app, server, socket, readyForIncomingConnections});
-    });
-  }
-
-  const socketPath = await makeSocketPath();
-  if (await checkSocketInUse(socketPath)) {
-    console.warn(
-      `Cannot start flipper-server because socket ${socketPath} is in use.`,
-    );
-    tracker.track('server-socket-already-in-use', {});
-  } else {
-    console.info(`Cleaning up stale socket ${socketPath}`);
-    await fs.rm(socketPath, {force: true});
-  }
-
-  const proxyServer: proxy | undefined = proxy.createProxyServer({
-    target: {host: 'localhost', port: 0, socketPath},
-    autoRewrite: true,
-    ws: true,
-  });
-
-  console.log('Starting socket server on ', socketPath);
-  if (proxyServer) {
-    console.log(`Starting proxy server on http://localhost:${config.port}`);
-  }
 
   exitHook(() => {
     console.log('Shutdown server');
-    proxyServer?.close();
     server.close();
-
-    console.log('Cleaning up socket on exit:', socketPath);
-    // This *must* run synchronously and we're not blocking any UI loop by definition.
-    // eslint-disable-next-line node/no-sync
-    fs.rmSync(socketPath, {force: true});
-  });
-
-  proxyServer?.on('error', (err, _req, _res) => {
-    console.warn('Error in proxy server:', err);
-    tracker.track('server-proxy-error', {error: err.message});
-
-    // As it stands, if the proxy fails, which is the one
-    // listening on the supplied TCP port, then we should exit.
-    // Otherwise we risk staying in an invalid state, unable
-    // to recover, and thus preventing us to serve incoming requests.
-    // Bear in mind that exiting the process will trigger the exit hook
-    // defined above which will clean and close the sockets.
-    process.exit(0);
   });
 
   return new Promise((resolve) => {
+    console.log(`Starting server on http://localhost:${config.port}`);
     const readyForIncomingConnections = (
       serverImpl: FlipperServerImpl,
       companionEnv: FlipperServerCompanionEnv,
     ): Promise<void> => {
       attachSocketServer(socket, serverImpl, companionEnv);
       return new Promise((resolve) => {
-        proxyServer?.listen(config.port);
+        server.listen(config.port, undefined, () => {
-        server.listen(socketPath, undefined, () => {
           tracker.track('server-started', {
             port: config.port,
           });
@@ -238,7 +154,7 @@ async function startProxyServer(
  * incoming connections origin.
  * @returns Returns the created WS.
  */
-function addWebsocket(server: http.Server, config: Config) {
+function attachWS(server: http.Server, config: Config) {
   const localhost = 'localhost';
   const localhostIPV4 = `localhost:${config.port}`;
   const localhostIPV6 = `[::1]:${config.port}`;

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

@@ -39,63 +39,3 @@ export async function checkPortInUse(port: number): Promise<boolean> {
       .listen(port);
   });
 }
-
-/**
- * Checks if a socket is in used for given path.
- * If the path doesn't exist then is not in use. If it does,
- * create a socket client and attempt to connect to it.
- * If the connection is established, then there's a process
- * already listening. Otherwise, it kind of indicates the
- * contrary.
- * @param path Path used instead of port number.
- * @returns True or false dependning on whether the socket is in
- * use or not.
- */
-export async function checkSocketInUse(path: string): Promise<boolean> {
-  if (!(await fs.pathExists(path))) {
-    return false;
-  }
-  return new Promise((resolve, _reject) => {
-    const client = net
-      .createConnection(path, () => {
-        resolve(true);
-        client.destroy();
-      })
-      .on('error', (e) => {
-        if (e.message.includes('ECONNREFUSED')) {
-          resolve(false);
-        } else {
-          console.warn(
-            `[conn] Socket ${path} is in use, but we don't know why.`,
-            e,
-          );
-          resolve(false);
-        }
-        client.destroy();
-      });
-  });
-}
-
-/**
- * Creates a socket path. Used to open the socket at location.
- * Format: flipper-server-${userInfo}.sock
- * @returns The created socket path.
- */
-export async function makeSocketPath(): Promise<string> {
-  const runtimeDir = xdgBasedir.runtime || '/tmp';
-  await fs.mkdirp(runtimeDir);
-  const filename = `flipper-server-${os.userInfo().uid}.sock`;
-  const path = `${runtimeDir}/${filename}`;
-
-  // Depending on the OS this is between 104 and 108:
-  // https://unix.stackexchange.com/a/367012/10198
-  if (path.length >= 104) {
-    console.warn(
-      'Ignoring XDG_RUNTIME_DIR as it would exceed the total limit for domain socket paths. See man 7 unix.',
-    );
-    // Even with the INT32_MAX userid, we should have plenty of room.
-    return `/tmp/${filename}`;
-  }
-
-  return path;
-}