Close #911

api/src/main/java/com/alibaba/nacos/api/naming/PreservedMetadataKeys.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.nacos.api.naming;
+
+/**
+ * Some keys of metadata that are recognized by Nacos
+ *
+ * @author nkorange
+ * @since 1.0.0
+ */
+public class PreservedMetadataKeys {
+
+    /**
+     * The key to indicate the registry source of service instance, such as Dubbo, SpringCloud, etc.
+     */
+    public static final String REGISTER_SOURCE = "preserved.register.source";
+}