update config (envconfig)

pkg/config/config.go

@@ -13,9 +13,10 @@ var viperInstance = viper.New()
 // BaseConfig can be used to import the base config parameters in the applications config struct.
 // Please use with tag `mapstructure:",squash"`.
 type BaseConfig struct {
-	LogLevel string `mapstructure:"logLevel"`
-	IsDev    bool   `mapstructure:"isDev"`
-	Port     int    `mapstructure:"servingPort"`
+	LogLevel   string `mapstructure:"logLevel" envconfig:"LOG_LEVEL" default:"info"`
+	IsDev      bool   `mapstructure:"isDev" envconfig:"IS_DEV" default:"false"`
+	ListenAddr string `mapstructure:"listenAddr" envconfig:"LISTEN_ADDR" default:"127.0.0.1"`
+	ListenPort int    `mapstructure:"listenPort" envconfig:"LISTEN_PORT" default:"8080"`
 }
 
 // LoadConfig sets given defaults and read in given config.
@@ -41,19 +42,21 @@ func readConfig(prefix string) error {
 	viperInstance.SetEnvPrefix(strings.ToTitle(prefix))
 	viperInstance.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
 
+	viperInstance.AutomaticEnv()
+
 	if err := viperInstance.ReadInConfig(); err != nil {
-		var configFileNotFoundError viper.ConfigFileNotFoundError
-		if !errors.As(err, &configFileNotFoundError) {
+		if !errors.Is(err, viper.ConfigFileNotFoundError{}) {
 			return fmt.Errorf("error read in configFile: %w", err)
 		}
 	}
-	viperInstance.AutomaticEnv()
+
 	return nil
 }
 
 func setDefaults(defaults map[string]any) {
 	viperInstance.SetDefault("logLevel", "info")
-	viperInstance.SetDefault("servingPort", 8080)
+	viperInstance.SetDefault("listenAddr", "127.0.0.1")
+	viperInstance.SetDefault("listenPort", 8080)
 
 	for key, value := range defaults {
 		viperInstance.SetDefault(key, value)