[3.0] Nacos, add switch and disable consumer side registration by default

dubbo-common/src/main/java/org/apache/dubbo/common/constants/RegistryConstants.java

@@ -126,4 +126,6 @@ public interface RegistryConstants {
     float DEFAULT_HASHMAP_LOAD_FACTOR = 0.75f;
 
     String ENABLE_EMPTY_PROTECTION_KEY = "enable-empty-protection";
+    String REGISTER_CONSUMER_URL_KEY = "register-consumer-url";
+
 }

dubbo-common/src/main/java/org/apache/dubbo/config/ApplicationConfig.java

@@ -165,6 +165,9 @@ public class ApplicationConfig extends AbstractConfig {
      */
     private String metadataType;
 
+    /**
+     * Used to control whether register instance to registry or not. Set to 'false' only when instance is pure consumer.
+     */
     private Boolean registerConsumer;
 
     private String repository;

dubbo-metadata/dubbo-metadata-api/src/main/java/org/apache/dubbo/metadata/MetadataConstants.java

@@ -27,4 +27,5 @@ public class MetadataConstants {
     public static final int DEFAULT_METADATA_PUBLISH_DELAY = 30000;
     public static final String METADATA_PROXY_TIMEOUT_KEY = "dubbo.application.metadata.proxy.delay";
     public static final int DEFAULT_METADATA_TIMEOUT_VALUE = 5000;
+    public static String REPORT_CONSUMER_URL_KEY = "report-consumer-definition";
 }

dubbo-metadata/dubbo-metadata-report-nacos/src/main/java/org/apache/dubbo/metadata/store/nacos/NacosMetadataReport.java

@@ -58,6 +58,7 @@
 import static org.apache.dubbo.common.constants.RemotingConstants.BACKUP_KEY;
 import static org.apache.dubbo.common.utils.StringConstantFieldValuePredicate.of;
 import static org.apache.dubbo.common.utils.StringUtils.HYPHEN_CHAR;
+import static org.apache.dubbo.metadata.MetadataConstants.REPORT_CONSUMER_URL_KEY;
 import static org.apache.dubbo.metadata.ServiceNameMapping.DEFAULT_MAPPING_GROUP;
 import static org.apache.dubbo.metadata.ServiceNameMapping.getAppNames;
 
@@ -179,7 +180,9 @@ protected void doStoreProviderMetadata(MetadataIdentifier providerMetadataIdenti
 
     @Override
     protected void doStoreConsumerMetadata(MetadataIdentifier consumerMetadataIdentifier, String value) {
-        this.storeMetadata(consumerMetadataIdentifier, value);
+        if (getUrl().getParameter(REPORT_CONSUMER_URL_KEY, false)) {
+            this.storeMetadata(consumerMetadataIdentifier, value);
+        }
     }
 
     @Override

dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistry.java

@@ -64,6 +64,7 @@
 import static org.apache.dubbo.common.constants.CommonConstants.INTERFACE_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.PATH_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.PROTOCOL_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.PROVIDER_SIDE;
 import static org.apache.dubbo.common.constants.CommonConstants.VERSION_KEY;
 import static org.apache.dubbo.common.constants.RegistryConstants.CATEGORY_KEY;
 import static org.apache.dubbo.common.constants.RegistryConstants.CONFIGURATORS_CATEGORY;
@@ -72,6 +73,7 @@
 import static org.apache.dubbo.common.constants.RegistryConstants.EMPTY_PROTOCOL;
 import static org.apache.dubbo.common.constants.RegistryConstants.ENABLE_EMPTY_PROTECTION_KEY;
 import static org.apache.dubbo.common.constants.RegistryConstants.PROVIDERS_CATEGORY;
+import static org.apache.dubbo.common.constants.RegistryConstants.REGISTER_CONSUMER_URL_KEY;
 import static org.apache.dubbo.common.constants.RegistryConstants.ROUTERS_CATEGORY;
 import static org.apache.dubbo.registry.Constants.ADMIN_PROTOCOL;
 import static org.apache.dubbo.registry.nacos.NacosServiceName.NAME_SEPARATOR;
@@ -166,16 +168,20 @@ public List<URL> lookup(final URL url) {
     @Override
     public void doRegister(URL url) {
         try {
-            String serviceName = getServiceName(url);
-            Instance instance = createInstance(url);
-            /**
-             *  namingService.registerInstance with {@link org.apache.dubbo.registry.support.AbstractRegistry#registryUrl}
-             *  default {@link DEFAULT_GROUP}
-             *
-             * in https://github.com/apache/dubbo/issues/5978
-             */
-            namingService.registerInstance(serviceName,
-                getUrl().getGroup(Constants.DEFAULT_GROUP), instance);
+            if (PROVIDER_SIDE.equals(url.getSide()) || getUrl().getParameter(REGISTER_CONSUMER_URL_KEY, false)) {
+                String serviceName = getServiceName(url);
+                Instance instance = createInstance(url);
+                /**
+                 *  namingService.registerInstance with {@link org.apache.dubbo.registry.support.AbstractRegistry#registryUrl}
+                 *  default {@link DEFAULT_GROUP}
+                 *
+                 * in https://github.com/apache/dubbo/issues/5978
+                 */
+                namingService.registerInstance(serviceName,
+                    getUrl().getGroup(Constants.DEFAULT_GROUP), instance);
+            } else {
+                logger.info("Please set 'dubbo.registry.parameters.register-consumer-url=true' to turn on consumer url registration.");
+            }
         } catch (Throwable cause) {
             throw new RpcException("Failed to register " + url + " to nacos " + getUrl() + ", cause: " + cause.getMessage(), cause);
         }