nacos客户端注册源码

Nacos源码 版本1.4.1
客户端源码
Nacos源码整合进spring是从spring.factory开始

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一般整合源码都是auto字样的类,整合的
这里就是NacosServiceRegistryAutoConfiguration类

@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnNacosDiscoveryEnabled
@ConditionalOnProperty(value = "spring.cloud.service-registry.auto-registration.enabled",
      matchIfMissing = true)
@AutoConfigureAfter({ AutoServiceRegistrationConfiguration.class,
      AutoServiceRegistrationAutoConfiguration.class,
      NacosDiscoveryAutoConfiguration.class })
public class NacosServiceRegistryAutoConfiguration {

   @Bean
   public NacosServiceRegistry nacosServiceRegistry(
         NacosDiscoveryProperties nacosDiscoveryProperties) {
      return new NacosServiceRegistry(nacosDiscoveryProperties);
   }

   @Bean
   @ConditionalOnBean(AutoServiceRegistrationProperties.class)
   public NacosRegistration nacosRegistration(
         ObjectProvider<List<NacosRegistrationCustomizer>> registrationCustomizers,
         NacosDiscoveryProperties nacosDiscoveryProperties,
         ApplicationContext context) {
      return new NacosRegistration(registrationCustomizers.getIfAvailable(),
            nacosDiscoveryProperties, context);
   }

   @Bean
   @ConditionalOnBean(AutoServiceRegistrationProperties.class)
   public NacosAutoServiceRegistration nacosAutoServiceRegistration(
         NacosServiceRegistry registry,
         AutoServiceRegistrationProperties autoServiceRegistrationProperties,
         NacosRegistration registration) {
      return new NacosAutoServiceRegistration(registry,
            autoServiceRegistrationProperties, registration);
   }

}

往容器中存放了三个bean NacosServiceRegistry NacosRegistration
NacosAutoServiceRegistration
NacosAutoServiceRegistration的继承图

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这里可以看到实现了ApplicationListener,spring的事件监听
那我们就看一下,监听的事件,父类AbstractAutoServiceRegistration的onApplicationEvent方法

@Override
@SuppressWarnings("deprecation")
public void onApplicationEvent(WebServerInitializedEvent event) {
   bind(event);
}

注意bind方法
看一下bind之后的调用链
bind(WebServerInitializedEvent event)
-->this.start();
-->AbstractAutoServiceRegistration#start
-->registerManagement();
-->this.serviceRegistry.register(registration);
-->NacosServiceRegistry#
-->namingService.registerInstance(serviceId, group, instance);
-->NacosNamingService#registerInstance(String serviceName, String groupName, Instance instance)
--> serverProxy.registerService(groupedServiceName, groupName, instance);
-->NamingProxy#registerService(String serviceName, String groupName, Instance instance)

registerService(String serviceName, String groupName, Instance instance)方法

public void registerService(String serviceName, String groupName, Instance instance) throws NacosException {
    
    NAMING_LOGGER.info("[REGISTER-SERVICE] {} registering service {} with instance: {}", namespaceId, serviceName,
            instance);
    
    final Map<String, String> params = new HashMap<String, String>(16);
    params.put(CommonParams.NAMESPACE_ID, namespaceId);
    params.put(CommonParams.SERVICE_NAME, serviceName);
    params.put(CommonParams.GROUP_NAME, groupName);
    params.put(CommonParams.CLUSTER_NAME, instance.getClusterName());
    params.put("ip", instance.getIp());
    params.put("port", String.valueOf(instance.getPort()));
    params.put("weight", String.valueOf(instance.getWeight()));
    params.put("enable", String.valueOf(instance.isEnabled()));
    params.put("healthy", String.valueOf(instance.isHealthy()));
    params.put("ephemeral", String.valueOf(instance.isEphemeral()));
    params.put("metadata", JacksonUtils.toJson(instance.getMetadata()));
    //向nacos服务端注册
// UtilAndComs.nacosUrlInstance  /nacos/v1/ns/instance 服务端http地址
//params参数
//post类型
    reqApi(UtilAndComs.nacosUrlInstance, params, HttpMethod.POST);
    
}

上面提到的params是如何被赋值的
NacosServiceRegistry#register(Registration registration)方法

Instance instance = getNacosInstanceFromRegistration(registration);

点进getNacosInstanceFromRegistration方法发现,就是最开始注册的三个bean之一
NacosServiceRegistry,获取配置文件中的属性
WebServerInitializedEvent事件是如何被推送的,大家可以断点,查看一下调用栈,会发现是spring的核心方法中的最后一个finishRefresh()方法,推送的事件.
讲解了客户端如何注册服务端的代码流程.
客户端是如何拉去客户端列表的

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那我们在看看NacosWatch类
会发现该类实现了SmartLifecycle接口,就是在bean都加载完成时候,会调用start方法
Start方法中有下面这段代码

namingService.subscribe(properties.getService(), properties.getGroup(),
      Arrays.asList(properties.getClusterName()), eventListener);

调用链
NacosNamingService#subscribe(String serviceName, String groupName, List<String> clusters, EventListener listener)
--> hostReactor.subscribe(NamingUtils.getGroupedName(serviceName, groupName), StringUtils.join(clusters, ","),listener);
-->HostReactor#subscribe(String serviceName, String clusters, EventListener eventListener)
-->getServiceInfo(serviceName, clusters);
-->HostReactor#getServiceInfo(final String serviceName, final String clusters)
--> scheduleUpdateIfAbsent(serviceName, clusters);
-->HostReactor#scheduleUpdateIfAbsent
-->ScheduledFuture<?> future = addTask(new UpdateTask(serviceName, clusters));
addTask方法,可以看到是定时任务线程池 其中DEFAULT为1000单位毫秒,1秒钟

public synchronized ScheduledFuture<?> addTask(UpdateTask task) {
    return executor.schedule(task, DEFAULT_DELAY, TimeUnit.MILLISECONDS);
}

定时任务,那我们是要关心UpdateTask的run方法的
其中updateService(serviceName, clusters);方法就是从服务端获取服务列表的
发现最终调用服务端接口的代码

public String queryList(String serviceName, String clusters, int udpPort, boolean healthyOnly)
        throws NacosException {
    
    final Map<String, String> params = new HashMap<String, String>(8);
    params.put(CommonParams.NAMESPACE_ID, namespaceId);
    params.put(CommonParams.SERVICE_NAME, serviceName);
    params.put("clusters", clusters);
    params.put("udpPort", String.valueOf(udpPort));
    params.put("clientIP", NetUtils.localIP());
    params.put("healthyOnly", String.valueOf(healthyOnly));
   //在注册源码的时候,我们就看到了repApi方法,这个方法就会发送http请求
//路径就是/instance/list 
    return reqApi(UtilAndComs.nacosUrlBase + "/instance/list", params, HttpMethod.GET);
}