开发环境一直在本地测试，启动的本地nacos，一直连接良好，测试没有问题

需要上测试环境，连接云服务器上的nacos就出问题了，一直提示

com.alibaba.nacos.api.exception.NacosException: failed to req API:/nacos/v1/ns/instance after all servers([127.0.0.1:8848]) tried: java.net.ConnectException: Connection refused: connect
    at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:556) ~[nacos-client-1.4.2.jar:na]
    at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:498) ~[nacos-client-1.4.2.jar:na]
    at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:493) ~[nacos-client-1.4.2.jar:na]
    at com.alibaba.nacos.client.naming.net.NamingProxy.registerService(NamingProxy.java:246) ~[nacos-client-1.4.2.jar:na]
    at 

甚是纳闷。

启动本地的nacos

配置项目yml，这里 serverAddr 配置的是127.0.0.1:8848

spring:
  application:
    name: nacos-service-provide
    cloud:
      nacos:
        discovery:
          username: nacos
          password: nacos
          serverAddr: 43.139.165.137:8848
        enabled: true

server:
  port: 9002

启动项目，控制台输出已经注册上了

 

 查看nacos控制台，可以看到确实注册上了

至此，证明本地注册没有问题，然后将 serverAddr 改为远程服务器的地址，重启运用

 神奇的事情发生了！！！结果还是连接的本地的！！！

 本地nacos控制台上显示服务数仍然是1

 而远程服务器上的却是，空空如也

难道是本地启动的nacos干扰了吗，会有限连接本地的？

把本地的nacos关掉试试

 

然后再重启运用， 好家伙，直接启动失败，failed to req API:/nacos/v1/ns/instance after all servers([127.0.0.1:8848]) tried: java.net.ConnectException

完整错误信息如下

2022-11-21 10:20:21.083 ERROR 9796 --- [           main] c.a.c.n.registry.NacosServiceRegistry    : nacos registry, nacos-service-provide register failed...NacosRegistration{nacosDiscoveryProperties=NacosDiscoveryProperties{serverAddr='127.0.0.1:8848', username='', password='', endpoint='', namespace='', watchDelay=30000, logName='', service='nacos-service-provide', weight=1.0, clusterName='DEFAULT', group='DEFAULT_GROUP', namingLoadCacheAtStart='false', metadata={preserved.register.source=SPRING_CLOUD}, registerEnabled=true, ip='192.168.101.132', networkInterface='', port=9002, secure=false, accessKey='', secretKey='', heartBeatInterval=null, heartBeatTimeout=null, ipDeleteTimeout=null, instanceEnabled=true, ephemeral=true, failureToleranceEnabled=false}, ipDeleteTimeout=null, failFast=true}},

com.alibaba.nacos.api.exception.NacosException: failed to req API:/nacos/v1/ns/instance after all servers([127.0.0.1:8848]) tried: java.net.ConnectException: Connection refused: connect
	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:556) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:498) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:493) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.net.NamingProxy.registerService(NamingProxy.java:246) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.NacosNamingService.registerInstance(NacosNamingService.java:212) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.cloud.nacos.registry.NacosServiceRegistry.register(NacosServiceRegistry.java:74) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.1.0.jar:2021.0.1.0]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.register(AbstractAutoServiceRegistration.java:239) [spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration.register(NacosAutoServiceRegistration.java:78) [spring-cloud-starter-alibaba-nacos-discovery-2021.0.1.0.jar:2021.0.1.0]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.start(AbstractAutoServiceRegistration.java:138) [spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.bind(AbstractAutoServiceRegistration.java:101) [spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:88) [spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:47) [spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:404) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:361) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.web.servlet.context.WebServerStartStopLifecycle.start(WebServerStartStopLifecycle.java:46) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:182) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:53) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:360) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:158) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:122) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:895) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554) [spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:755) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:402) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at com.fast.alibaba.NacosServiceProvider9002.main(NacosServiceProvider9002.java:13) [classes/:na]

2022-11-21 10:20:21.083  WARN 9796 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Failed to start bean 'webServerStartStop'; nested exception is java.lang.reflect.UndeclaredThrowableException
2022-11-21 10:20:30.100  INFO 9796 --- [           main] o.s.s.c.ThreadPoolTaskScheduler          : Shutting down ExecutorService 'Nacos-Watch-Task-Scheduler'
2022-11-21 10:20:30.102  INFO 9796 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'
2022-11-21 10:20:30.333  INFO 9796 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2022-11-21 10:20:30.364  INFO 9796 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-11-21 10:20:30.395 ERROR 9796 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.context.ApplicationContextException: Failed to start bean 'webServerStartStop'; nested exception is java.lang.reflect.UndeclaredThrowableException
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:185) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:53) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:360) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:158) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:122) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:895) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:755) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:402) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1247) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1236) [spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at com.fast.alibaba.NacosServiceProvider9002.main(NacosServiceProvider9002.java:13) [classes/:na]
Caused by: java.lang.reflect.UndeclaredThrowableException: null
	at org.springframework.util.ReflectionUtils.rethrowRuntimeException(ReflectionUtils.java:147) ~[spring-core-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at com.alibaba.cloud.nacos.registry.NacosServiceRegistry.register(NacosServiceRegistry.java:82) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.1.0.jar:2021.0.1.0]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.register(AbstractAutoServiceRegistration.java:239) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at com.alibaba.cloud.nacos.registry.NacosAutoServiceRegistration.register(NacosAutoServiceRegistration.java:78) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.1.0.jar:2021.0.1.0]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.start(AbstractAutoServiceRegistration.java:138) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.bind(AbstractAutoServiceRegistration.java:101) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:88) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.cloud.client.serviceregistry.AbstractAutoServiceRegistration.onApplicationEvent(AbstractAutoServiceRegistration.java:47) ~[spring-cloud-commons-2.2.9.RELEASE.jar:2.2.9.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:404) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:361) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	at org.springframework.boot.web.servlet.context.WebServerStartStopLifecycle.start(WebServerStartStopLifecycle.java:46) ~[spring-boot-2.3.12.RELEASE.jar:2.3.12.RELEASE]
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:182) ~[spring-context-5.2.15.RELEASE.jar:5.2.15.RELEASE]
	... 14 common frames omitted
Caused by: com.alibaba.nacos.api.exception.NacosException: failed to req API:/nacos/v1/ns/instance after all servers([127.0.0.1:8848]) tried: java.net.ConnectException: Connection refused: connect
	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:556) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:498) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:493) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.net.NamingProxy.registerService(NamingProxy.java:246) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.nacos.client.naming.NacosNamingService.registerInstance(NacosNamingService.java:212) ~[nacos-client-1.4.2.jar:na]
	at com.alibaba.cloud.nacos.registry.NacosServiceRegistry.register(NacosServiceRegistry.java:74) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.1.0.jar:2021.0.1.0]
	... 27 common frames omitted

2022-11-21 10:20:30.396  WARN 9796 --- [      Thread-18] c.a.nacos.common.notify.NotifyCenter     : [NotifyCenter] Start destroying Publisher
2022-11-21 10:20:30.396  WARN 9796 --- [      Thread-18] c.a.nacos.common.notify.NotifyCenter     : [NotifyCenter] Destruction of the end
2022-11-21 10:20:30.396  WARN 9796 --- [      Thread-12] c.a.n.common.http.HttpClientBeanHolder   : [HttpClientBeanHolder] Start destroying common HttpClient
2022-11-21 10:20:30.397  WARN 9796 --- [      Thread-12] c.a.n.common.http.HttpClientBeanHolder   : [HttpClientBeanHolder] Destruction of the end

异常的信息显示127.0.0.1:8848拒绝连接，本地的nacos都停止了，当然会拒绝，可项目明明配置了nacos地址，为什么还会去连接本地的呢？

我的第一反应是配置写错了，导致启动时在某个地方加载了默认的配置，为此还特意debug了一下启动流程，看到service的名称确实是我配置取的，就以为自己的配置应该是没问题的

往往你以为没问题的地方，就有问题！

往往你以为没问题的地方，就有问题！！

往往你以为没问题的地方，就有问题！！

往往你以为没问题的地方，就有问题！！！

 再仔细看看这个debug信息：

service的信息是正确的，因为它取的是spring.application.name

 

serverAddr有信息，但值不符合预期

username、password、endpoint却莫名其妙的成了空的，什么也没有

回到配置文件，这些可都是配置了的！！！

 突然反应过来，还是自己的配置文件写错了，只有name是对的

因为name属性的全称是spring.application.name，

而serverAddr的全称本应该是：spring.cloud.nacos.discovery.serverAddr

但我配置成了spring.application.cloud.nacos.discovery.serverAddr

多了一个application层级！！！

导致这些值都未被读取，所以才用了默认的127.0.0.1！！！

解决方案

将配置文件改正即可

 

总结

编码无小事，切不可粗心大意。