feat: ignore hidden feature files

Signed-off-by: AhmedGrati <ahmedgrati1999@gmail.com>

docs/usage/customization-guide.md

@@ -234,10 +234,12 @@ further be used in label rules specified in
 [`custom`](#custom-feature-source) feature source.
 
 > **NOTE:** Be careful when creating and/or updating hook or feature files
-> while NFD is running. In order to avoid race conditions you should write into
-> a temporary file (outside the `source.d` and `features.d` directories), and,
-> atomically create/update the original file by doing a filesystem move
-> operation.
+> while NFD is running. In order to avoid race conditions you should write
+> into a temporary file, and atomically create/update the original file by
+> doing a file rename operation. NFD ignores dot files,
+> so temporary file can be written to the same directory and renamed
+> (`.my.feature` -> `my.feature`) once file is complete. Both file names should
+> (obviously) be unique for the given application.
 
 ### An example
 

source/local/local.go

@@ -248,6 +248,10 @@ func getFeaturesFromHooks() (map[string]string, error) {
 
 	for _, file := range files {
 		fileName := file.Name()
+		// ignore hidden feature file
+		if strings.HasPrefix(fileName, ".") {
+			continue
+		}
 		lines, err := runHook(fileName)
 		if err != nil {
 			klog.ErrorS(err, "failed to run hook", "fileName", fileName)
@@ -324,6 +328,10 @@ func getFeaturesFromFiles() (map[string]string, error) {
 
 	for _, file := range files {
 		fileName := file.Name()
+		// ignore hidden feature file
+		if strings.HasPrefix(fileName, ".") {
+			continue
+		}
 		lines, err := getFileContent(fileName)
 		if err != nil {
 			klog.ErrorS(err, "failed to read file", "fileName", fileName)

source/local/testdata/features.d/.my.feature

@@ -0,0 +1 @@
+hiddenFeatureKey=hiddenFeatureValue