WIP: Add DNS Mode as default peer resolver

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

@@ -160,4 +160,14 @@ public interface Constants {
     String DEFAULT_NATIVE_PROXY = "jdk";
 
     String DEFAULT_APP_NAME = "DEFAULT_DUBBO_APP";
+
+    String DNS_NAME = "dnsName";
+
+    String TARGET_PORT = "targetPort";
+
+    String TARGET_PROTOCOL = "targetProtocol";
+
+    String DNS_REGISTRY = "dns";
+
+    String DNS_DEFAULT_NAMESERVER = "DEFAULT_DNS_HOST";
 }

dubbo-config/dubbo-config-api/pom.xml

@@ -152,6 +152,13 @@
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>org.apache.dubbo</groupId>
+      <artifactId>dubbo-registry-dns</artifactId>
+      <version>${project.parent.version}</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.apache.dubbo</groupId>
       <artifactId>dubbo-registry-zookeeper</artifactId>

dubbo-config/dubbo-config-api/src/main/java/org/apache/dubbo/config/ReferenceConfig.java

@@ -25,7 +25,6 @@
 import org.apache.dubbo.common.logger.ErrorTypeAwareLogger;
 import org.apache.dubbo.common.logger.LoggerFactory;
 import org.apache.dubbo.common.url.component.ServiceConfigURL;
-import org.apache.dubbo.common.utils.ArrayUtils;
 import org.apache.dubbo.common.utils.CollectionUtils;
 import org.apache.dubbo.common.utils.ConfigUtils;
 import org.apache.dubbo.common.utils.NetUtils;
@@ -40,7 +39,6 @@
 import org.apache.dubbo.rpc.ProxyFactory;
 import org.apache.dubbo.rpc.cluster.Cluster;
 import org.apache.dubbo.rpc.cluster.directory.StaticDirectory;
-import org.apache.dubbo.rpc.cluster.support.ClusterUtils;
 import org.apache.dubbo.rpc.cluster.support.registry.ZoneAwareCluster;
 import org.apache.dubbo.rpc.model.AsyncMethodInfo;
 import org.apache.dubbo.rpc.model.ConsumerModel;
@@ -65,6 +63,7 @@
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.Collectors;
 
 import static org.apache.dubbo.common.constants.CommonConstants.ANY_VALUE;
 import static org.apache.dubbo.common.constants.CommonConstants.CLUSTER_DOMAIN;
@@ -76,14 +75,14 @@
 import static org.apache.dubbo.common.constants.CommonConstants.DEFAULT_MESH_PORT;
 import static org.apache.dubbo.common.constants.CommonConstants.DubboProperty.DUBBO_IP_TO_REGISTRY;
 import static org.apache.dubbo.common.constants.CommonConstants.INTERFACE_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.LAZY_CONNECT_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.LOCALHOST_VALUE;
 import static org.apache.dubbo.common.constants.CommonConstants.MESH_ENABLE;
 import static org.apache.dubbo.common.constants.CommonConstants.METHODS_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.MONITOR_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.POD_NAMESPACE;
 import static org.apache.dubbo.common.constants.CommonConstants.PROXY_CLASS_REF;
 import static org.apache.dubbo.common.constants.CommonConstants.REVISION_KEY;
-import static org.apache.dubbo.common.constants.CommonConstants.SEMICOLON_SPLIT_PATTERN;
 import static org.apache.dubbo.common.constants.CommonConstants.SIDE_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.SVC;
 import static org.apache.dubbo.common.constants.CommonConstants.TRIPLE;
@@ -101,7 +100,7 @@
 import static org.apache.dubbo.registry.Constants.REGISTER_IP_KEY;
 import static org.apache.dubbo.rpc.Constants.GENERIC_KEY;
 import static org.apache.dubbo.rpc.Constants.LOCAL_PROTOCOL;
-import static org.apache.dubbo.rpc.cluster.Constants.PEER_KEY;
+import static org.apache.dubbo.rpc.cluster.Constants.CLUSTER_STICKY_KEY;
 import static org.apache.dubbo.rpc.cluster.Constants.REFER_KEY;
 
 /**
@@ -492,13 +491,7 @@ private T createProxy(Map<String, String> referenceParameters) {
 
         meshModeHandleUrl(referenceParameters);
 
-        if (StringUtils.isNotEmpty(url)) {
-            // user specified URL, could be peer-to-peer address, or register center's address.
-            parseUrl(referenceParameters);
-        } else {
-            // if protocols not in jvm checkRegistry
-            aggregateUrlFromRegistry(referenceParameters);
-        }
+        aggregateUrlFromRegistry(referenceParameters);
         createInvoker();
 
         if (logger.isInfoEnabled()) {
@@ -599,39 +592,41 @@ private boolean checkMeshConfig(Map<String, String> referenceParameters) {
         return true;
     }
 
-    /**
-     * Parse the directly configured url.
-     */
-    private void parseUrl(Map<String, String> referenceParameters) {
-        String[] us = SEMICOLON_SPLIT_PATTERN.split(url);
-        if (ArrayUtils.isNotEmpty(us)) {
-            for (String u : us) {
-                URL url = URL.valueOf(u);
-                if (StringUtils.isEmpty(url.getPath())) {
-                    url = url.setPath(interfaceName);
-                }
-                url = url.setScopeModel(getScopeModel());
-                url = url.setServiceModel(consumerModel);
-                if (UrlUtils.isRegistry(url)) {
-                    urls.add(url.putAttribute(REFER_KEY, referenceParameters));
-                } else {
-                    URL peerUrl = getScopeModel()
-                            .getApplicationModel()
-                            .getBeanFactory()
-                            .getBean(ClusterUtils.class)
-                            .mergeUrl(url, referenceParameters);
-                    peerUrl = peerUrl.putAttribute(PEER_KEY, true);
-                    urls.add(peerUrl);
-                }
-            }
-        }
-    }
-
     /**
      * Get URLs from the registry and aggregate them.
      */
     private void aggregateUrlFromRegistry(Map<String, String> referenceParameters) {
         checkRegistry();
+        if (StringUtils.isNoneEmpty(url)) {
+            // user specified URL, could be peer-to-peer address, or register center's address.
+            URL u = URL.valueOf(url);
+            if (StringUtils.isEmpty(u.getPath())) {
+                u = u.setPath(interfaceName);
+            }
+            referenceParameters.put(Constants.TARGET_PROTOCOL, u.getProtocol());
+            referenceParameters.put(Constants.DNS_NAME, u.getHost());
+            referenceParameters.put(Constants.TARGET_PORT, String.valueOf(u.getPort()));
+            u.getParameters().forEach(referenceParameters::putIfAbsent);
+            // Use sticky first to reduce connections
+            referenceParameters.putIfAbsent(CLUSTER_STICKY_KEY, Boolean.TRUE.toString());
+            // TODO Triple should support lazy connect
+            referenceParameters.putIfAbsent(LAZY_CONNECT_KEY, Boolean.TRUE.toString());
+
+            if (!getRegistries().isEmpty()) {
+                // If the URL has been set, only support DNS registry
+                setRegistries(getRegistries().stream()
+                        .filter(registryConfig -> Constants.DNS_REGISTRY.equals(registryConfig.getProtocol()))
+                        .collect(Collectors.toList()));
+            }
+            if (getRegistries().isEmpty()) {
+                // If none of the registries are configured, use the default DNS registry
+                RegistryConfig registryConfig = new RegistryConfig();
+                registryConfig.setProtocol(Constants.DNS_REGISTRY);
+                registryConfig.setAddress(Constants.DNS_DEFAULT_NAMESERVER);
+                registryConfig.refresh();
+                setRegistry(registryConfig);
+            }
+        }
         List<URL> us = ConfigValidationUtils.loadRegistries(this, false);
         if (CollectionUtils.isNotEmpty(us)) {
             for (URL u : us) {

dubbo-demo/dubbo-demo-triple/pom.xml

@@ -74,6 +74,11 @@
       <artifactId>dubbo-registry-nacos</artifactId>
       <version>${project.version}</version>
     </dependency>
+    <dependency>
+      <groupId>org.apache.dubbo</groupId>
+      <artifactId>dubbo-registry-dns</artifactId>
+      <version>${project.version}</version>
+    </dependency>
     <dependency>
       <groupId>com.alibaba.nacos</groupId>
       <artifactId>nacos-client</artifactId>

dubbo-demo/dubbo-demo-triple/src/main/java/org/apache/dubbo/demo/consumer/ApiConsumer.java

@@ -16,12 +16,9 @@
  */
 package org.apache.dubbo.demo.consumer;
 
-import org.apache.dubbo.common.constants.CommonConstants;
 import org.apache.dubbo.common.stream.StreamObserver;
 import org.apache.dubbo.config.ApplicationConfig;
-import org.apache.dubbo.config.ProtocolConfig;
 import org.apache.dubbo.config.ReferenceConfig;
-import org.apache.dubbo.config.RegistryConfig;
 import org.apache.dubbo.config.bootstrap.DubboBootstrap;
 import org.apache.dubbo.demo.GreeterService;
 import org.apache.dubbo.demo.hello.HelloReply;
@@ -36,9 +33,7 @@ public class ApiConsumer {
     public static void main(String[] args) throws InterruptedException {
         ReferenceConfig<GreeterService> referenceConfig = new ReferenceConfig<>();
         referenceConfig.setInterface(GreeterService.class);
-        referenceConfig.setCheck(false);
-        referenceConfig.setProtocol(CommonConstants.TRIPLE);
-        referenceConfig.setLazy(true);
+        referenceConfig.setUrl("tri://localhost:50051");
         referenceConfig.setTimeout(100000);
         if (args.length > 0 && Constants.HTTP3_KEY.equals(args[0])) {
             referenceConfig.setParameters(Collections.singletonMap(Constants.HTTP3_KEY, "true"));
@@ -47,8 +42,6 @@ public static void main(String[] args) throws InterruptedException {
         DubboBootstrap bootstrap = DubboBootstrap.getInstance();
         bootstrap
                 .application(new ApplicationConfig("dubbo-demo-triple-api-consumer"))
-                .registry(new RegistryConfig("zookeeper://127.0.0.1:2181"))
-                .protocol(new ProtocolConfig(CommonConstants.TRIPLE, -1))
                 .reference(referenceConfig)
                 .start();
 

dubbo-demo/dubbo-demo-triple/src/main/java/org/apache/dubbo/demo/provider/ApiProvider.java

@@ -19,7 +19,6 @@
 import org.apache.dubbo.common.constants.CommonConstants;
 import org.apache.dubbo.config.ApplicationConfig;
 import org.apache.dubbo.config.ProtocolConfig;
-import org.apache.dubbo.config.RegistryConfig;
 import org.apache.dubbo.config.ServiceConfig;
 import org.apache.dubbo.config.bootstrap.DubboBootstrap;
 import org.apache.dubbo.demo.GreeterService;
@@ -41,8 +40,7 @@ public static void main(String[] args) {
         DubboBootstrap bootstrap = DubboBootstrap.getInstance();
         bootstrap
                 .application(new ApplicationConfig("dubbo-demo-triple-api-provider"))
-                .registry(new RegistryConfig("zookeeper://127.0.0.1:2181"))
-                .protocol(new ProtocolConfig(CommonConstants.TRIPLE, -1))
+                .protocol(new ProtocolConfig(CommonConstants.TRIPLE, 50051))
                 .service(serviceConfig)
                 .start()
                 .await();

dubbo-distribution/dubbo-all/pom.xml

@@ -320,6 +320,13 @@
       <scope>compile</scope>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>org.apache.dubbo</groupId>
+      <artifactId>dubbo-registry-dns</artifactId>
+      <version>${project.version}</version>
+      <scope>compile</scope>
+      <optional>true</optional>
+    </dependency>
 
     <!-- remoting -->
     <dependency>
@@ -496,6 +503,7 @@
                   <include>org.apache.dubbo:dubbo-registry-multiple</include>
                   <include>org.apache.dubbo:dubbo-registry-nacos</include>
                   <include>org.apache.dubbo:dubbo-registry-zookeeper</include>
+                  <include>org.apache.dubbo:dubbo-registry-dns</include>
                   <include>org.apache.dubbo:dubbo-remoting-api</include>
                   <include>org.apache.dubbo:dubbo-remoting-http12</include>
                   <include>org.apache.dubbo:dubbo-remoting-http3</include>

dubbo-registry/dubbo-registry-dns/pom.xml

@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>org.apache.dubbo</groupId>
+    <artifactId>dubbo-registry</artifactId>
+    <version>${revision}</version>
+    <relativePath>../pom.xml</relativePath>
+  </parent>
+
+  <artifactId>dubbo-registry-dns</artifactId>
+  <packaging>jar</packaging>
+  <name>${project.artifactId}</name>
+  <description>The DNS registry module of dubbo project</description>
+  <properties>
+    <skip_maven_deploy>false</skip_maven_deploy>
+  </properties>
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.dubbo</groupId>
+      <artifactId>dubbo-registry-api</artifactId>
+      <version>${project.parent.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>io.netty</groupId>
+      <artifactId>netty-all</artifactId>
+    </dependency>
+  </dependencies>
+
+</project>