nacos-client实例注册源码分析

pom.xml 引入

<dependency>
      <groupId>com.alibaba.cloud</groupId>
      <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
      <version>2021.1</version>
  </dependency>

找到 spring.factories 文件

spring-cloud-starter-alibaba-nacos-discoveryjar包下找到MATE-INF/spring.factories 文件；可以看到 自动装配类NacosServiceRegistryAutoConfiguration

 com.alibaba.cloud.nacos.registry.NacosServiceRegistryAutoConfiguration

实例注册 NacosAutoServiceRegistration

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

NacosServiceRegistryAutoConfiguration 会自动创建关键类 NacosAutoServiceRegistration Bean；该类的父类AbstractAutoServiceRegistration 实现了 ApplicationContextAware 会在 SpringBean 创建完成后自动调用。

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

@Deprecated
public void bind(WebServerInitializedEvent event) {
  ApplicationContext context = event.getApplicationContext();
  if (context instanceof ConfigurableWebServerApplicationContext) {
    if ("management".equals(((ConfigurableWebServerApplicationContext) context).getServerNamespace())) {
      return;
    }
  }
  this.port.compareAndSet(0, event.getWebServer().getPort());
  // 开始注册客户端
  this.start();
}  

public void start() {
 //.......
  //触发注册
 register();
  //......
}

protected void register() {
  //服务注册：serviceRegistry是NacosServiceRegistry的实例
  this.serviceRegistry.register(getRegistration());
}

注册具体实现类 NacosServiceRegistry

注册核心代码

 @Override
 public void register(Registration registration) {

  if (StringUtils.isEmpty(registration.getServiceId())) {
   log.warn("No service to register for nacos client...");
   return;
  }

  NamingService namingService = namingService();
  String serviceId = registration.getServiceId();
  String group = nacosDiscoveryProperties.getGroup();

  Instance instance = getNacosInstanceFromRegistration(registration);

  try {
      //开始注册实例
   namingService.registerInstance(serviceId, group, instance);
   log.info("nacos registry, {} {} {}:{} register finished", group, serviceId,
     instance.getIp(), instance.getPort());
  }
  catch (Exception e) {
   log.error("nacos registry, {} register failed...{},", serviceId,
     registration.toString(), e);
   // rethrow a RuntimeException if the registration is failed.
   // issue : https://github.com/alibaba/spring-cloud-alibaba/issues/1132
   rethrowRuntimeException(e);
  }
 }

NamingHttpClientProxy 注册代理类

@Override
  public void registerService(String serviceName, String groupName, Instance instance) throws NacosException {
      //.......
      //把自己作为实例注册到nacos-server
      reqApi(UtilAndComs.nacosUrlInstance, params, HttpMethod.POST);

  }
  
  public String reqApi(String api, Map<String, String> params, Map<String, String> body, List<String> servers,
            String method) throws NacosException {
        //.......
        if (serverListManager.isDomain()) {
            //.......
            //调用服务接口
            return callServer(api, params, body, nacosDomain, method);
        } else {
            //.......
           //调用服务接口
            return callServer(api, params, body, server, method);
            }
        }
        //.......
    }

实例注册接口/nacos/v1/ns/instance

https://nacos.io/zh-cn/docs/open-api.html#2.1