[#238] node: Read cfg from dir even if cfg file not set

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

pkg/util/config/dir.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"fmt"
 	"os"
 	"path"
 
@@ -20,7 +21,7 @@ func ReadConfigDir(v *viper.Viper, configDir string) error {
 			continue
 		}
 		ext := path.Ext(entry.Name())
-		if ext != ".yaml" && ext != ".yml" {
+		if ext != ".yaml" && ext != ".yml" && ext != ".json" {
 			continue
 		}
 
@@ -33,22 +34,15 @@ func ReadConfigDir(v *viper.Viper, configDir string) error {
 }
 
 // mergeConfig reads config file and merge its content with current viper.
-func mergeConfig(v *viper.Viper, fileName string) (err error) {
-	var cfgFile *os.File
-	cfgFile, err = os.Open(fileName)
+func mergeConfig(v *viper.Viper, fileName string) error {
+	cv := viper.New()
+	cv.SetConfigFile(fileName)
+	err := cv.ReadInConfig()
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to read config: %w", err)
 	}
-
-	defer func() {
-		errClose := cfgFile.Close()
-		if err == nil {
-			err = errClose
-		}
-	}()
-
-	if err = v.MergeConfig(cfgFile); err != nil {
-		return err
+	if err = v.MergeConfigMap(cv.AllSettings()); err != nil {
+		return fmt.Errorf("failed to merge config: %w", err)
 	}
 
 	return nil