fix unmarshal dump.transformation from env variable

cmd/greenmask/cmd/root.go

@@ -137,6 +137,8 @@ func initConfig() {
 	decoderCfg := func(cfg *mapstructure.DecoderConfig) {
 		cfg.DecodeHook = mapstructure.ComposeDecodeHookFunc(
 			configUtils.ParamsToByteSliceHookFunc(),
+			configUtils.StringToStructHookFunc(),
+			configUtils.StringToSliceWithBracketHookFunc(),
 			mapstructure.StringToTimeDurationHookFunc(),
 			mapstructure.StringToSliceHookFunc(","),
 		)

internal/utils/config/mapstructure_hook.go

@@ -46,3 +46,60 @@ func ParamsToByteSliceHookFunc() mapstructure.DecodeHookFunc {
 		}
 	}
 }
+
+func StringToSliceWithBracketHookFunc() mapstructure.DecodeHookFunc {
+	return func(
+		f reflect.Kind,
+		t reflect.Kind,
+		data interface{}) (interface{}, error) {
+		if f != reflect.String || t != reflect.Slice {
+			return data, nil
+		}
+
+		raw := data.(string)
+		if raw == "" {
+			return []string{}, nil
+		}
+		var slice []json.RawMessage
+		err := json.Unmarshal([]byte(raw), &slice)
+		if err != nil {
+			return data, nil
+		}
+
+		var strSlice []string
+		for _, v := range slice {
+			strSlice = append(strSlice, string(v))
+		}
+		return strSlice, nil
+	}
+}
+
+func StringToStructHookFunc() mapstructure.DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{},
+	) (interface{}, error) {
+		if f.Kind() != reflect.String ||
+			(t.Kind() != reflect.Struct && !(t.Kind() == reflect.Pointer && t.Elem().Kind() == reflect.Struct)) {
+			return data, nil
+		}
+		raw := data.(string)
+		var val reflect.Value
+		// Struct or the pointer to a struct
+		if t.Kind() == reflect.Struct {
+			val = reflect.New(t)
+		} else {
+			val = reflect.New(t.Elem())
+		}
+
+		if raw == "" {
+			return val, nil
+		}
+		err := json.Unmarshal([]byte(raw), val.Interface())
+		if err != nil {
+			return data, nil
+		}
+		return val.Interface(), nil
+	}
+}