Nacos - 客户端注册

Nacos - 启动中提到了注册的入口，这里就讲一下注册的细节。
Tomcat启动成功后，会调用AbstractAutoServiceRegistration的onApplicationEvent方法，他会继续调用AbstractAutoServiceRegistration#bind。

AbstractAutoServiceRegistration#bind

public void bind(WebServerInitializedEvent event) {
    ApplicationContext context = event.getApplicationContext();
    if (context instanceof ConfigurableWebServerApplicationContext) {
        if ("management".equals(((ConfigurableWebServerApplicationContext) context)
                .getServerNamespace())) {
            return;
        }
    }
    // 设置端口号
    this.port.compareAndSet(0, event.getWebServer().getPort());
    this.start();
}

AbstractAutoServiceRegistration#start

public void start() {
    if (!isEnabled()) {
        if (logger.isDebugEnabled()) {
            logger.debug("Discovery Lifecycle disabled. Not starting");
        }
        return;
    }

    // only initialize if nonSecurePort is greater than 0 and it isn't already running
    // because of containerPortInitializer below
    // 没启动过才注册
    if (!this.running.get()) {
        // 发布InstancePreRegisteredEvent事件
        this.context.publishEvent(
                new InstancePreRegisteredEvent(this, getRegistration()));
        // 注册
        register();
        if (shouldRegisterManagement()) {
            // 注册registerManagement
            registerManagement();
        }
        // 发布InstanceRegisteredEvent事件
        this.context.publishEvent(
                new InstanceRegisteredEvent<>(this, getConfiguration()));
        // 设置状态为启动
        this.running.compareAndSet(false, true);
    }

}

NacosAutoServiceRegistration#register

protected void register() {
    if (!this.registration.getNacosDiscoveryProperties().isRegisterEnabled()) {
        log.debug("Registration disabled.");
        return;
    }
    // 小于0从新设置端口
    if (this.registration.getPort() < 0) {
        this.registration.setPort(getPort().get());
    }
    super.register();
}

AbstractAutoServiceRegistration#register

registration的注入在启动的时候已经说过了。

protected void register() {
    this.serviceRegistry.register(getRegistration());
}

NacosServiceRegistry#register

封装好Instance后，调用NacosNamingService的registerInstance方法注册。Nacos - NacosNamingService初始化以及几个其余定时任务已经讲过了。

public void register(Registration registration) {

    if (StringUtils.isEmpty(registration.getServiceId())) {
        log.warn("No service to register for nacos client...");
        return;
    }
    // 获取NacosNamingService
    NamingService namingService = namingService();
    // 获取serviceId
    String serviceId = registration.getServiceId();
    String group = nacosDiscoveryProperties.getGroup();
    // 获取Instance，一些信息从registration读取，一些从nacosDiscoveryProperties读取
    Instance instance = getNacosInstanceFromRegistration(registration);

    try {
        // 注册
        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);
    }
}

NacosNamingService#registerInstance

封装心跳信息、开启定时任务续约以及调用serverProxy注册，这个url是/nacos/v1/ns/instance。

public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException {
    String groupedServiceName = NamingUtils.getGroupedName(serviceName, groupName);
    if (instance.isEphemeral()) {
        // 封装心跳信息
        BeatInfo beatInfo = beatReactor.buildBeatInfo(groupedServiceName, instance);
        // 开启定时任务续约
        beatReactor.addBeatInfo(groupedServiceName, beatInfo);
    }
    serverProxy.registerService(groupedServiceName, groupName, instance);
}