Bootstrap logging and performance improvement

Summary:
Add a few console logs as to highlight how long does it take for our server to start.

Additionally, do not wait until we are ready for client connections before attempting to launch. There's nothing else we do at this point. Instead, launch and wait until we are ready.

Reviewed By: passy

Differential Revision: D46639482

fbshipit-source-id: c098d229edc3cd52e5c876c509a7c81532635afa

desktop/flipper-server/src/index.tsx

@@ -149,8 +149,16 @@ async function shutdown() {
 }
 
 async function start() {
+  console.info('[flipper-server][bootstrap] Booting up');
+  const t0 = performance.now();
+
   const enhanceLogger = await initializeLogger(staticPath);
 
+  const t1 = performance.now();
+  console.info(
+    `[flipper-server][bootstrap] Logger initialised (${t1 - t0} ms)`,
+  );
+
   let keytar: any = undefined;
   try {
     if (!isTest()) {
@@ -170,6 +178,9 @@ async function start() {
     console.error('[flipper-server] Failed to load keytar:', e);
   }
 
+  const t2 = performance.now();
+  console.info(`[flipper-server][bootstrap] Keytar loaded (${t2 - t1} ms)`);
+
   const isProduction =
     process.env.NODE_ENV !== 'development' && process.env.NODE_ENV !== 'test';
 
@@ -180,16 +191,21 @@ async function start() {
   );
 
   if (await checkPortInUse(argv.port)) {
-    console.warn(`[flipper-server] Port ${argv.port} is already in use.`);
+    console.warn(`[flipper-server] Port ${argv.port} is already in use`);
     if (!argv.replace) {
-      console.info(
-        `[flipper-server] Not replacing existing instance, exiting.`,
-      );
+      console.info(`[flipper-server] Not replacing existing instance, exiting`);
       return;
     }
     await shutdown();
   }
 
+  const t3 = performance.now();
+  console.info(
+    `[flipper-server][bootstrap] Check for running instances completed (${
+      t3 - t2
+    } ms)`,
+  );
+
   const {app, server, socket, readyForIncomingConnections} = await startServer({
     staticPath,
     entry: `index.web${argv.bundler ? '.dev' : ''}.html`,
@@ -197,7 +213,11 @@ async function start() {
     tcp: argv.tcp,
   });
 
-  // maybe at this point we could open up, http server is running.
+  const t4 = performance.now();
+
+  console.info(
+    `[flipper-server][bootstrap] HTTP server started (${t4 - t3} ms)`,
+  );
 
   const flipperServer = await startFlipperServer(
     rootPath,
@@ -209,6 +229,11 @@ async function start() {
     environmentInfo,
   );
 
+  const t5 = performance.now();
+  console.info(
+    `[flipper-server][bootstrap] FlipperServer created (${t5 - t4} ms)`,
+  );
+
   exitHook(async () => {
     await flipperServer.close();
   });
@@ -218,6 +243,15 @@ async function start() {
   });
 
   const companionEnv = await initCompanionEnv(flipperServer);
+
+  const t6 = performance.now();
+
+  console.info(
+    `[flipper-server][bootstrap] Companion environment initialised (${
+      t6 - t5
+    } ms)`,
+  );
+
   if (argv.failFast) {
     flipperServer.on('server-state', ({state}) => {
       if (state === 'error') {
@@ -230,12 +264,27 @@ async function start() {
   }
   await flipperServer.connect();
 
+  const t7 = performance.now();
+  console.info(
+    `[flipper-server][bootstrap] Ready for app connections (${t7 - t6} ms)`,
+  );
+
   if (argv.bundler) {
     await attachDevServer(app, server, socket, rootPath);
   }
-  await readyForIncomingConnections(flipperServer, companionEnv);
 
-  console.log('[flipper-server] listening at port ' + chalk.green(argv.port));
+  const t8 = performance.now();
+  console.info(
+    `[flipper-server][bootstrap] Development server attached (${t8 - t7} ms)`,
+  );
+  readyForIncomingConnections(flipperServer, companionEnv);
+
+  const t9 = performance.now();
+  console.info(
+    `[flipper-server][bootstrap] Listening at port ${chalk.green(argv.port)} (${
+      t9 - t8
+    } ms)`,
+  );
 }
 
 async function launch() {