Merge pull request #7238 from Incanta/fix/fs-watch-memory-leak

Fix fs.watch leak with a timestamp to prevent repetitive buildFromConfig

pkg/rancher-desktop/main/tray.ts

@@ -35,9 +35,11 @@ export class Tray {
   private settings: Settings;
   private currentNetworkStatus: networkStatus = networkStatus.CHECKING;
   private static instance: Tray;
-  private abortController: AbortController | undefined;
   private networkState: boolean | undefined;
   private networkInterval: NodeJS.Timeout;
+  private runBuildFromConfigTimer: NodeJS.Timeout | null = null;
+  private kubeConfigWatchers: fs.FSWatcher[] = [];
+  private fsWatcherInterval: NodeJS.Timeout;
 
   protected contextMenuItems: Electron.MenuItemConstructorOptions[] = [
     {
@@ -130,18 +132,19 @@ export class Tray {
    * triggered, close the watcher and restart after a duration (one second).
    */
   private async watchForChanges() {
-    const abortController = new AbortController();
+    for (const watcher of this.kubeConfigWatchers) {
+      watcher.close();
+    }
+    this.kubeConfigWatchers = [];
 
-    this.abortController = abortController;
     const paths = await kubeconfig.getKubeConfigPaths();
     const options: fs.WatchOptions = {
       persistent: false,
       recursive:  !this.isLinux(), // Recursive not implemented in Linux
       encoding:   'utf-8',
-      signal:     abortController.signal,
     };
 
-    paths.map(filepath => fs.watch(filepath, options, async(eventType) => {
+    this.kubeConfigWatchers = paths.map(filepath => fs.watch(filepath, options, async(eventType) => {
       if (eventType === 'rename') {
         try {
           await fs.promises.access(filepath);
@@ -151,10 +154,12 @@ export class Tray {
         }
       }
 
-      this.abortController?.abort();
-      this.buildFromConfig();
-
-      setTimeout(this.watchForChanges.bind(this), 1_000);
+      // This prevents calling buildFromConfig multiple times in quick succession
+      // while making sure that the last file change within the period is processed.
+      this.runBuildFromConfigTimer ||= setTimeout(() => {
+        this.runBuildFromConfigTimer = null;
+        this.buildFromConfig();
+      }, 1_000);
     }));
   }
 
@@ -183,16 +188,20 @@ export class Tray {
     this.buildFromConfig();
     this.watchForChanges();
 
+    // We reset the watchers on an interval in the event that `fs.watch` silently
+    // fails to keep watching. This original issue is documented at
+    // https://github.com/rancher-sandbox/rancher-desktop/pull/2038 and further discussed at
+    // https://github.com/rancher-sandbox/rancher-desktop/pull/7238#discussion_r1690128729
+    this.fsWatcherInterval = setInterval(() => this.watchForChanges(), 5 * 60_000);
+
     mainEvents.on('backend-locked-update', this.backendStateEvent);
     mainEvents.emit('backend-locked-check');
     mainEvents.on('k8s-check-state', this.k8sStateChangedEvent);
     mainEvents.on('settings-update', this.settingsUpdateEvent);
 
-    /**
-     * This triggers the CONNECTED_TO_INTERNET diagnostic at a set interval and
-     * updates the network status in the tray if there's a change in the network
-     * state.
-     */
+    // This triggers the CONNECTED_TO_INTERNET diagnostic at a set interval and
+    // updates the network status in the tray if there's a change in the network
+    // state.
     this.networkInterval = setInterval(async() => {
       const networkDiagnostic = await mainEvents.invoke('diagnostics-trigger', 'CONNECTED_TO_INTERNET');
 
@@ -242,11 +251,19 @@ export class Tray {
    */
   public hide() {
     this.trayMenu.destroy();
-    this.abortController?.abort();
     mainEvents.off('k8s-check-state', this.k8sStateChangedEvent);
     mainEvents.off('settings-update', this.settingsUpdateEvent);
     ipcMainProxy.removeListener('update-network-status', this.updateNetworkStatusEvent);
+    clearInterval(this.fsWatcherInterval);
     clearInterval(this.networkInterval);
+    if (this.runBuildFromConfigTimer) {
+      clearTimeout(this.runBuildFromConfigTimer);
+      this.runBuildFromConfigTimer = null;
+    }
+    for (const watcher of this.kubeConfigWatchers) {
+      watcher.close();
+    }
+    this.kubeConfigWatchers = [];
   }
 
   /**