Finalize log stream before exiting process

Reviewed By: antonk52

Differential Revision: D51229230

fbshipit-source-id: 0e7f657a170eb8602ade9abf1db1976c5b51dc3f

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

@@ -583,6 +583,7 @@ export class FlipperServerImpl implements FlipperServer {
       return uploadRes;
     },
     shutdown: async () => {
+      // Do not use processExit helper. We want to server immediatelly quit when this call is triggerred
       process.exit(0);
     },
     'is-logged-in': async () => {

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

@@ -13,6 +13,7 @@ export * from './tracker';
 export {loadLauncherSettings} from './utils/launcherSettings';
 export {loadProcessConfig} from './utils/processConfig';
 export {getEnvironmentInfo} from './utils/environmentInfo';
+export {processExit, setProcessExitRoutine} from './utils/processExit';
 export {getGatekeepers} from './gk';
 export {setupPrefetcher} from './fb-stubs/Prefetcher';
 export * from './server/attachSocketServer';

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

@@ -29,6 +29,7 @@ import {URLSearchParams} from 'url';
 import {tracker} from '../tracker';
 import {getFlipperServerConfig} from '../FlipperServerConfig';
 import {performance} from 'perf_hooks';
+import {processExit} from '../utils/processExit';
 
 const safe = (f: () => void) => {
   try {
@@ -266,7 +267,7 @@ export function attachSocketServer(
             console.info(
               '[flipper-server] Shutdown as no clients are currently connected',
             );
-            process.exit(0);
+            processExit(0);
           }
         }, FIVE_HOURS);
       }

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

@@ -27,6 +27,7 @@ import {EnvironmentInfo, isProduction} from 'flipper-common';
 import {GRAPH_SECRET} from '../fb-stubs/constants';
 import {sessionId} from '../sessionId';
 import {UIPreference, openUI} from '../utils/openUI';
+import {processExit} from '../utils/processExit';
 
 type Config = {
   port: number;
@@ -123,7 +124,7 @@ export async function startServer(
       console.error(
         `[flipper-server] Unable to become ready within ${timeoutSeconds} seconds, exit`,
       );
-      process.exit(1);
+      processExit(1);
     }
   }, timeoutSeconds * 1000);
 
@@ -192,6 +193,7 @@ async function startHTTPServer(
     res.json({success: true});
 
     // Just exit the process, this will trigger the shutdown hooks.
+    // Do not use prcoessExit util as we want the serve to shutdown immediately
     process.exit(0);
   });
 
@@ -226,7 +228,7 @@ async function startHTTPServer(
         `[flipper-server] Unable to listen at port: ${config.port}, is already in use`,
       );
       tracker.track('server-socket-already-in-use', {});
-      process.exit(1);
+      processExit(1);
     }
   });
 

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

@@ -50,7 +50,9 @@ export async function checkServerRunning(
   port: number,
 ): Promise<string | undefined> {
   try {
-    const response = await fetch(`http://localhost:${port}/info`);
+    const response = await fetch(`http://localhost:${port}/info`, {
+      timeout: 1000,
+    });
     if (response.status >= 200 && response.status < 300) {
       const environmentInfo: EnvironmentInfo = await response.json();
       return environmentInfo.appVersion;
@@ -74,7 +76,9 @@ export async function checkServerRunning(
  */
 export async function shutdownRunningInstance(port: number): Promise<boolean> {
   try {
-    const response = await fetch(`http://localhost:${port}/shutdown`);
+    const response = await fetch(`http://localhost:${port}/shutdown`, {
+      timeout: 1000,
+    });
     if (response.status >= 200 && response.status < 300) {
       const json = await response.json();
       console.info(

desktop/flipper-server-core/src/utils/processExit.tsx

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const onBeforeExitFns: (() => void | Promise<void>)[] = [];
+export const setProcessExitRoutine = (
+  onBeforeExit: () => void | Promise<void>,
+) => {
+  onBeforeExitFns.push(onBeforeExit);
+};
+
+const resIsPromise = (res: void | Promise<void>): res is Promise<void> =>
+  res instanceof Promise;
+export const processExit = async (code: number) => {
+  console.debug('processExit', code);
+
+  // eslint-disable-next-line promise/catch-or-return
+  await Promise.all(
+    onBeforeExitFns.map(async (fn) => {
+      try {
+        const res = fn();
+        if (resIsPromise(res)) {
+          return res.catch((e) => {
+            console.error('Process exit routine failed', e);
+          });
+        }
+      } catch (e) {
+        console.error('Process exit routine failed', e);
+      }
+    }),
+  ).finally(() => {
+    process.exit(code);
+  });
+
+  setTimeout(() => {
+    console.error('Process exit routines timed out');
+    process.exit(code);
+  }, 5000);
+};

desktop/flipper-server/src/index.tsx

@@ -30,6 +30,7 @@ import {
   startFlipperServer,
   startServer,
   tracker,
+  processExit,
 } from 'flipper-server-core';
 import {addLogTailer, isProduction, isTest, LoggerFormat} from 'flipper-common';
 import exitHook from 'exit-hook';
@@ -265,7 +266,7 @@ async function start() {
         console.error(
           '[flipper-server] state changed to error, process will exit.',
         );
-        process.exit(1);
+        processExit(1);
       }
     });
   }
@@ -335,7 +336,7 @@ process.on('uncaughtException', (error) => {
     error,
   );
   reportBrowserConnection(false);
-  process.exit(1);
+  processExit(1);
 });
 
 process.on('unhandledRejection', (reason, promise) => {
@@ -347,8 +348,15 @@ process.on('unhandledRejection', (reason, promise) => {
   );
 });
 
-start().catch((e) => {
+// Node.js process never waits for all promises to settle and exits as soon as there is not pending timers or open sockets or tasks in teh macroqueue
+const runtimeTimeout = setTimeout(() => {}, Number.MAX_SAFE_INTEGER);
+// eslint-disable-next-line promise/catch-or-return
+start()
+  .catch((e) => {
     console.error(chalk.red('Server startup error: '), e);
     reportBrowserConnection(false);
-  process.exit(1);
-});
+    return processExit(1);
+  })
+  .finally(() => {
+    clearTimeout(runtimeTimeout);
+  });

desktop/flipper-server/src/logger.tsx

@@ -21,7 +21,10 @@ import fsRotator from 'file-stream-rotator';
 import {ensureFile} from 'fs-extra';
 import {access} from 'fs/promises';
 import {constants} from 'fs';
-import {initializeLogger as initLogger} from 'flipper-server-core';
+import {
+  initializeLogger as initLogger,
+  setProcessExitRoutine,
+} from 'flipper-server-core';
 
 export const loggerOutputFile = 'flipper-server-log.out';
 
@@ -64,4 +67,14 @@ export async function initializeLogger(
       logStream?.write(`${name}: \n${stack}\n`);
     }
   });
+
+  const finalizeLogger = async () => {
+    const logStreamToEnd = logStream;
+    // Prevent future writes
+    logStream = undefined;
+    await new Promise<void>((resolve) => {
+      logStreamToEnd?.end(resolve);
+    });
+  };
+  setProcessExitRoutine(finalizeLogger);
 }