fix: use shared fsnotify watcher to avoid 'too many open files' error (#236)

Author: johnlanni

src/apiserver/pkg/apiserver/apiserver.go

@@ -19,6 +19,7 @@ package apiserver
 import (
 	"fmt"
 
+	"github.com/fsnotify/fsnotify"
 	istiov1alpha3 "istio.io/client-go/pkg/apis/networking/v1alpha3"
 	admregv1 "k8s.io/api/admissionregistration/v1"
 	authzv1 "k8s.io/api/authorization/v1"
@@ -169,6 +170,15 @@ func (c completedConfig) New() (*HigressServer, error) {
 		}
 	}
 
+	// Create shared watcher for file storage mode to avoid "too many open files"
+	var sharedWatcher *fsnotify.Watcher
+	if storageMode == options.Storage_File {
+		sharedWatcher, err = fsnotify.NewWatcher()
+		if err != nil {
+			return nil, fmt.Errorf("failed to create shared file watcher: %v", err)
+		}
+	}
+
 	storageCreateFunc := func(
 		groupResource schema.GroupResource,
 		runtimeCodec runtime.Codec,
@@ -185,7 +195,7 @@ func (c completedConfig) New() (*HigressServer, error) {
 		switch storageMode {
 		case options.Storage_File:
 			runtimeCodec = codec.NewFlatAwareCodec(groupResource, runtimeCodec)
-			return registry.NewFileREST(groupResource, runtimeCodec, storageOptions.FileOptions.RootDir, extension, isNamespaced, singularName, newFunc, newListFunc, attrFunc)
+			return registry.NewFileREST(groupResource, runtimeCodec, storageOptions.FileOptions.RootDir, extension, isNamespaced, singularName, newFunc, newListFunc, attrFunc, sharedWatcher)
 		case options.Storage_Nacos:
 			var encryptionKey []byte = nil
 			if sensitive {

src/apiserver/pkg/registry/file_rest.go

@@ -54,6 +54,7 @@ func NewFileREST(
 	newFunc func() runtime.Object,
 	newListFunc func() runtime.Object,
 	attrFunc storage.AttrFunc,
+	sharedWatcher *fsnotify.Watcher,
 ) (REST, error) {
 	if attrFunc == nil {
 		if isNamespaced {
@@ -62,10 +63,6 @@ func NewFileREST(
 			attrFunc = storage.DefaultClusterScopedAttr
 		}
 	}
-	watcher, err := fsnotify.NewWatcher()
-	if err != nil {
-		return nil, err
-	}
 	// file REST
 	f := &fileREST{
 		TableConvertor: rest.NewDefaultTableConvertor(groupResource),
@@ -78,7 +75,7 @@ func NewFileREST(
 		newFunc:        newFunc,
 		newListFunc:    newListFunc,
 		attrFunc:       attrFunc,
-		dirWatcher:     watcher,
+		dirWatcher:     sharedWatcher,
 		fileWatchers:   make(map[string]*fileWatch, 10),
 	}
 	err = f.startDirWatcher()
@@ -115,7 +112,8 @@ func (f *fileREST) GetSingularName() string {
 }
 
 func (f *fileREST) Destroy() {
-	_ = f.dirWatcher.Close()
+	// Don't close the watcher as it's shared across all fileREST instances
+	// The watcher will be closed when the server shuts down
 }
 
 func (f *fileREST) startDirWatcher() error {