【Eureka】【06】Eureka Clinet注册和状态改变时重新注册信息

核心类EurekaDiscoveryClientConfiguration、DiscoveryClient、InstanceInfoReplicator

https://docs.spring.io/spring-boot/docs/1.3.5.RELEASE/reference/html/production-ready-endpoints.html#production-ready-health

https://docs.spring.io/spring-boot/docs/2.0.0.RELEASE/reference/html/production-ready-endpoints.html#production-ready-health

1.bean单利初始化完成后，执行SmartLifecycle的start方法

org.springframework.cloud.netflix.eureka.EurekaDiscoveryClientConfiguration.start()

@Configuration
@EnableConfigurationProperties
@ConditionalOnClass(EurekaClientConfig.class)
@ConditionalOnProperty(value = "eureka.client.enabled", matchIfMissing = true)
@CommonsLog
public class EurekaDiscoveryClientConfiguration implements SmartLifecycle, Ordered {
	@Autowired
	private EurekaClient eurekaClient;
	
	@Autowired
	private CloudEurekaInstanceConfig instanceConfig;

	@Override
	public void start() {
		// only set the port if the nonSecurePort is 0 and this.port != 0
		if (this.port.get() != 0 && this.instanceConfig.getNonSecurePort() == 0) {
			this.instanceConfig.setNonSecurePort(this.port.get());
		}

		// only initialize if nonSecurePort is greater than 0 and it isn't already running
		// because of containerPortInitializer below
		if (!this.running.get() && this.instanceConfig.getNonSecurePort() > 0) {

			maybeInitializeClient();

			if (log.isInfoEnabled()) {
				log.info("Registering application " + this.instanceConfig.getAppname()
						+ " with eureka with status "
						+ this.instanceConfig.getInitialStatus());
			}

			this.applicationInfoManager
					.setInstanceStatus(this.instanceConfig.getInitialStatus());

			if (this.healthCheckHandler != null) {
				this.eurekaClient.registerHealthCheck(this.healthCheckHandler);
			}
			this.context.publishEvent(
					new InstanceRegisteredEvent<>(this, this.instanceConfig));
			this.running.set(true);
		}
		
	}

	private void maybeInitializeClient() {
		// force initialization of possibly scoped proxies
		this.applicationInfoManager.getInfo();
		this.eurekaClient.getApplications();
	}

}