02、SpringCloud Alibaba - nacos服务自动注册流程
一、NacosServiceRegistryAutoConfiguration
@Configuration(proxyBeanMethods = false)
@EnableConfigurationProperties
@ConditionalOnNacosDiscoveryEnabled
# 默认开启服务自动注册
@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);
}
}
配置类中设计到的几个bean：NacosServiceRegistry 、NacosRegistration 、NacosAutoServiceRegistration 、AutoServiceRegistrationConfiguration
NacosServiceRegistry ： 实现服务的注册逻辑
NacosRegistration ： 通过 NacosRegistrationCustomizer 实现类定制化服务
NacosAutoServiceRegistration ： 服务启动后自动注册的入口
AutoServiceRegistrationConfiguration : 用于注册 AutoServiceRegistrationProperties``
二、注册流程
1、 NacosAutoServiceRegistration；
它实现了ApplicationListener，监听 WebServerInitializedEvent 事件，
在spring容器启动过程中，WebServerStartStopLifecycle 发布了 ServletWebServerInitializedEvent
public void start() {
this.webServer.start();
this.running = true;
this.applicationContext.publishEvent(new ServletWebServerInitializedEvent(this.webServer, this.applicationContext));
}
2、 bind()；
AbstractAutoServiceRegistration.java
public void bind(WebServerInitializedEvent event) {
ApplicationContext context = event.getApplicationContext();
if (context instanceof ConfigurableWebServerApplicationContext) {
if ("management".equals(((ConfigurableWebServerApplicationContext) context).getServerNamespace())) {
return;
}
}
//端口绑定
this.port.compareAndSet(0, event.getWebServer().getPort());
this.start();
}
3、 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
if (!this.running.get()) {
//发布服务注册前的事件
this.context.publishEvent(new InstancePreRegisteredEvent(this, getRegistration()));
//服务注册
register();
if (shouldRegisterManagement()) {
registerManagement();
}
//发布服务注册事件
this.context.publishEvent(new InstanceRegisteredEvent<>(this, getConfiguration()));
//运行状态设置为true
this.running.compareAndSet(false, true);
}
}
4、 register()；
@Override
protected void register() {
//校验注册功能是否打开
if (!this.registration.getNacosDiscoveryProperties().isRegisterEnabled()) {
log.debug("Registration disabled.");
return;
}
if (this.registration.getPort() < 0) {
this.registration.setPort(getPort().get());
}
//注册
super.register();
}
protected void register() {
//调用 NacosServiceRegistry
this.serviceRegistry.register(getRegistration());
}
5、 register()；
NacosServiceRegistry.java
public void register(Registration registration) {
if (StringUtils.isEmpty(registration.getServiceId())) {
log.warn("No service to register for nacos client...");
return;
}
//获取 NamingService
NamingService namingService = namingService();
String serviceId = registration.getServiceId();
String group = nacosDiscoveryProperties.getGroup();
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);
}
}
6、 registerInstance()；
@Override
public void registerInstance(String serviceName, String groupName, Instance instance) throws NacosException {
NamingUtils.checkInstanceIsLegal(instance);
String groupedServiceName = NamingUtils.getGroupedName(serviceName, groupName);
if (instance.isEphemeral()) {
//构造心跳信息
BeatInfo beatInfo = beatReactor.buildBeatInfo(groupedServiceName, instance);
//开启心跳检测
beatReactor.addBeatInfo(groupedServiceName, beatInfo);
}
//服务注册
serverProxy.registerService(groupedServiceName, groupName, instance);
}
7、 addBeatInfo()；
public void addBeatInfo(String serviceName, BeatInfo beatInfo) {
NAMING_LOGGER.info("[BEAT] adding beat: {} to beat map.", beatInfo);
String key = buildKey(serviceName, beatInfo.getIp(), beatInfo.getPort());
BeatInfo existBeat = null;
//fix1733
if ((existBeat = dom2Beat.remove(key)) != null) {
existBeat.setStopped(true);
}
dom2Beat.put(key, beatInfo);
//创建心跳检测任务 BeatTask，线程池执行该任务
executorService.schedule(new BeatTask(beatInfo), beatInfo.getPeriod(), TimeUnit.MILLISECONDS);
MetricsMonitor.getDom2BeatSizeMonitor().set(dom2Beat.size());
}
8、 registerService()；
调用nacos服务端注册服务
public void registerService(String serviceName, String groupName, Instance instance) throws NacosException {
NAMING_LOGGER.info("[REGISTER-SERVICE] {} registering service {} with instance: {}", namespaceId, serviceName,
instance);
//构造请求参数
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()));
//通过 NamingProxy调用nacos api进行服务注册
reqApi(UtilAndComs.nacosUrlInstance, params, HttpMethod.POST);
}
9、 BeatTask；
定时任务向nacos服务端发送心跳消息
class BeatTask implements Runnable {
BeatInfo beatInfo;
public BeatTask(BeatInfo beatInfo) {
this.beatInfo = beatInfo;
}
@Override
public void run() {
if (beatInfo.isStopped()) {
return;
}
long nextTime = beatInfo.getPeriod();
try {
//请求nacos api心跳接口
JsonNode result = serverProxy.sendBeat(beatInfo, BeatReactor.this.lightBeatEnabled);
long interval = result.get("clientBeatInterval").asLong();
boolean lightBeatEnabled = false;
if (result.has(CommonParams.LIGHT_BEAT_ENABLED)) {
lightBeatEnabled = result.get(CommonParams.LIGHT_BEAT_ENABLED).asBoolean();
}
BeatReactor.this.lightBeatEnabled = lightBeatEnabled;
if (interval > 0) {
nextTime = interval;
}
//校验返回状态码
int code = NamingResponseCode.OK;
if (result.has(CommonParams.CODE)) {
code = result.get(CommonParams.CODE).asInt();
}
if (code == NamingResponseCode.RESOURCE_NOT_FOUND) {
Instance instance = new Instance();
instance.setPort(beatInfo.getPort());
instance.setIp(beatInfo.getIp());
instance.setWeight(beatInfo.getWeight());
instance.setMetadata(beatInfo.getMetadata());
instance.setClusterName(beatInfo.getCluster());
instance.setServiceName(beatInfo.getServiceName());
instance.setInstanceId(instance.getInstanceId());
instance.setEphemeral(true);
try {
//服务资源不存在，重新注册
serverProxy.registerService(beatInfo.getServiceName(),
NamingUtils.getGroupName(beatInfo.getServiceName()), instance);
} catch (Exception ignore) {
}
}
} catch (NacosException ex) {
NAMING_LOGGER.error("[CLIENT-BEAT] failed to send beat: {}, code: {}, msg: {}",
JacksonUtils.toJson(beatInfo), ex.getErrCode(), ex.getErrMsg());
}
//延时调度 BeatTask
executorService.schedule(new BeatTask(beatInfo), nextTime, TimeUnit.MILLISECONDS);
}
}