想了解 spring-cloud-kubernetes，那就先来实战一把官方demo

Posted 2022-03-22 华为云开发者社区

tags:

篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了想了解 spring-cloud-kubernetes，那就先来实战一把官方demo相关的知识，希望对你有一定的参考价值。

本文分享自华为云社区《spring-cloud-kubernetes官方demo运行实战》，作者： 程序员欣宸。

关于spring-cloud-kubernetes

spring-cloud-kubernetes是springcloud官方推出的开源项目，用于将Spring Cloud和Spring Boot应用运行在kubernetes环境，并且提供了通用的接口来调用kubernetes服务，GitHub上官方地址是：https://github.com/spring-cloud/spring-cloud-kubernetes

官方demo

官方提供了简单的demo用于快速了解spring-cloud-kubernetes，我们就来一起将此demo源码编译构建，然后在kubernetes环境运行；

环境信息

本次实战的环境和版本信息如下：

操作系统：CentOS Linux release 7.6.1810
minikube：1.1.1
Java：1.8.0_191
Maven：3.6.0
fabric8-maven-plugin插件：3.5.37
spring-cloud-kubernetes：1.0.1.RELEASE

上面提到的linux、minikube、java、maven，请确保已全部准备好，关于linux环境下minikube的安装和启动请参考《Linux安装minikube指南》

下载源码

官方demo包含在整个spring-cloud-kubernetes开源项目中，因此要下载整个开源项目，由于主干的提交一直很活跃，因此最好下载个release版本，我这里下载的是v1.0.1.RELEASE，如下图红框所示，地址是：https://github.com/spring-cloud/spring-cloud-kubernetes/releases

修改maven设置

需要事先修改maven的设置，否则编译构建的时候会报错：

打开maven的配置文件settings.xml，完整路径是apache-maven-3.6.0/conf/settings.xm；
在settings.xml文件内，找到pluginGroups节点，在里面增加两行，修改完成后效果如下：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-xml"><span style="color:#e2777a"><span style="color:#e2777a"><span style="color:#cccccc"><</span>pluginGroups</span><span style="color:#cccccc">></span></span>
    <span style="color:#e2777a"><span style="color:#e2777a"><span style="color:#cccccc"><</span>pluginGroup</span><span style="color:#cccccc">></span></span>io.fabric8<span style="color:#e2777a"><span style="color:#e2777a"><span style="color:#cccccc"></</span>pluginGroup</span><span style="color:#cccccc">></span></span>
    <span style="color:#e2777a"><span style="color:#e2777a"><span style="color:#cccccc"><</span>pluginGroup</span><span style="color:#cccccc">></span></span>org.springframework.boot<span style="color:#e2777a"><span style="color:#e2777a"><span style="color:#cccccc"></</span>pluginGroup</span><span style="color:#cccccc">></span></span>
  <span style="color:#e2777a"><span style="color:#e2777a"><span style="color:#cccccc"></</span>pluginGroups</span><span style="color:#cccccc">></span></span>
</code></span></span>

修改完毕保存退出，maven设置完成；

如果您想了解该错误的细节，请参考文章《使用fabric8-maven-plugin插件的错误处理(No plugin found for prefix ‘fabric8’)》

编译项目源码

将上图中的源码下载解压，得到一个新的文件夹spring-cloud-kubernetes-1.0.1.RELEASE；
进入文件夹spring-cloud-kubernetes-1.0.1.RELEASE，执行命令mvn clean compile -U，完全编译整个工程，由于要下载大量依赖库所以较为耗时，我这里是二十分钟以上（这一步不是必须的，看个人爱好吧），构建通过后如下所示：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Reactor Summary <span style="color:#cc99cd">for</span> Spring Cloud Kubernetes <span style="color:#f08d49">1.0</span>.1.RELEASE:
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Dependencies <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.077</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">2.575</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Core <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span>01:51 min<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Config <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span> <span style="color:#f08d49">21.357</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Discovery <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">6.473</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Ribbon <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span> <span style="color:#f08d49">31.616</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Starter <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.558</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Starter :: Config <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.569</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Starter :: Ribbon <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.595</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Starter :: All <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.571</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Examples <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.558</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Examples :: Reload ConfigMap SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">9.077</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Examples :: Hello World <span style="color:#cc99cd">.</span> SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">1.323</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Leader <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span> SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">7.395</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Examples :: Leader Election SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.594</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Istio <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span> <span style="color:#f08d49">12.788</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.574</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Simple Core SUCCESS <span style="color:#cccccc">[</span>02:14 min<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Simple Configmap SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.646</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Istio SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.623</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Discovery Parent SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.564</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Discovery Service A SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.605</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Discovery Service B SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.625</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Discovery Client SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.608</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes :: Integration Tests :: Discovery Tests SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">1.440</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Spring Cloud Kubernetes Docs <span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span><span style="color:#cccccc">..</span>. SUCCESS <span style="color:#cccccc">[</span>  <span style="color:#f08d49">0.583</span> s<span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> BUILD SUCCESS
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Total time:  05:53 min
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Finished at: <span style="color:#f08d49">2019</span>-06-08T19:32:19+08:00
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------

</code></span></span>

进入目录spring-cloud-kubernetes-1.0.1.RELEASE/spring-cloud-kubernetes-examples/kubernetes-hello-world-example,这里面就是官方的入门demo，执行以下命令开始构建并且会部署到minikube：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell">mvn clean package fabric8:deploy -Pkubernetes
</code></span></span>

构建和部署完成后，控制台输出以下信息：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">..</span>.
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Installing /usr/local/work/demo/spring-cloud-kubernetes-1.0.1.RELEASE/spring-cloud-kubernetes-examples/kubernetes-hello-world-example/target/kubernetes-hello-world-1.0.1.RELEASE-sources.jar to /root/.m2/repository/org/springframework/cloud/kubernetes-hello-world/1.0.1.RELEASE/kubernetes-hello-world-1.0.1.RELEASE-sources.jar
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> <span style="color:#67cdcc"><<<</span> fabric8-maven-plugin:3.5.37:deploy <span style="color:#cccccc">(</span>default-cli<span style="color:#cccccc">)</span> <span style="color:#67cdcc"><</span> <span style="color:#f08d49">install</span> @ kubernetes-hello-world <span style="color:#67cdcc"><<<</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> --- fabric8-maven-plugin:3.5.37:deploy <span style="color:#cccccc">(</span>default-cli<span style="color:#cccccc">)</span> @ kubernetes-hello-world ---
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> F8: Using Kubernetes at https://192.168.121.133:8443/ <span style="color:#cc99cd">in</span> namespace default with manifest /usr/local/work/demo/spring-cloud-kubernetes-1.0.1.RELEASE/spring-cloud-kubernetes-examples/kubernetes-hello-world-example/target/classes/META-INF/fabric8/kubernetes.yml 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Using namespace: default
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Creating a Service from kubernetes.yml namespace default name kubernetes-hello-world
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Created Service: spring-cloud-kubernetes-examples/kubernetes-hello-world-example/target/fabric8/applyJson/default/service-kubernetes-hello-world.json
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Using namespace: default
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Creating a Deployment from kubernetes.yml namespace default name kubernetes-hello-world
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Created Deployment: spring-cloud-kubernetes-examples/kubernetes-hello-world-example/target/fabric8/applyJson/default/deployment-kubernetes-hello-world.json
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> F8: HINT: Use the <span style="color:#cc99cd">command</span> <span style="color:#7ec699"><span style="color:#7ec699">`</span>kubectl get pods -w<span style="color:#7ec699">`</span></span> to <span style="color:#f08d49">watch</span> your pods start up
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> BUILD SUCCESS
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Total time:  <span style="color:#f08d49">16.047</span> s
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Finished at: <span style="color:#f08d49">2019</span>-06-08T19:50:50+08:00
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
</code></span></span>

查看服务，已经创建了，类型是NodePort ,并且将8080端口映射到宿主机的30700端口，说明可以用http://宿主机IP:30700来访问此服务：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">[</span>root@minikube kubernetes-hello-world-example<span style="color:#cccccc">]</span><span style="color:#999999"># kubectl get services</span>
NAME                     TYPE        CLUSTER-IP       EXTERNAL-IP   PORT<span style="color:#cccccc">(</span>S<span style="color:#cccccc">)</span>          AGE
kubernetes               ClusterIP   <span style="color:#f08d49">10.96</span>.0.1        <span style="color:#67cdcc"><</span>none<span style="color:#67cdcc">></span>        <span style="color:#f08d49">443</span>/TCP          10h
kubernetes-hello-world   NodePort    <span style="color:#f08d49">10.108</span>.214.207   <span style="color:#67cdcc"><</span>none<span style="color:#67cdcc">></span>        <span style="color:#f08d49">8080</span>:30700/TCP   4m
</code></span></span>

查看部署，发现始终未能进入READY状态：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">[</span>root@minikube kubernetes-hello-world-example<span style="color:#cccccc">]</span><span style="color:#999999"># kubectl get deployments</span>
NAME                     READY   UP-TO-DATE   AVAILABLE   AGE
kubernetes-hello-world   <span style="color:#f08d49">0</span>/1     <span style="color:#f08d49">1</span>            <span style="color:#f08d49">0</span>           4m46s
</code></span></span>

查看pod，发现新建的pod始终未能进入READY状态：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">[</span>root@minikube kubernetes-hello-world-example<span style="color:#cccccc">]</span><span style="color:#999999"># kubectl get pods</span>
NAME                                      READY   STATUS    RESTARTS   AGE
kubernetes-hello-world-7578f45c5d-hr4r7   <span style="color:#f08d49">0</span>/1     Running   <span style="color:#f08d49">1</span>          6m
</code></span></span>

从上面的信息可以看出，部署虽然已经完成，但是pod是不可用的，访问网页试试，如下图，果然无法访问：

检查问题

执行命令kubectl describe pod kubernetes-hello-world-7578f45c5d-hr4r7检查pod的具体情况，如下图红框所示，两个探针检查都失败了：
再看看控制台输出的pod基本情况，里面有探针的信息，如下图所示，两个探针的地址都是/health：
打开demo的源码，如下所示，根本就没有路径为/health的服务：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-java"><span style="color:#cccccc">@RestController</span>
<span style="color:#cc99cd">public</span> <span style="color:#cc99cd">class</span> <span style="color:#f8c555">HelloController</span> <span style="color:#cccccc"></span>

        <span style="color:#cc99cd">private</span> <span style="color:#cc99cd">static</span> <span style="color:#cc99cd">final</span> <span style="color:#f8c555">Log</span> log <span style="color:#67cdcc">=</span> <span style="color:#f8c555">LogFactory</span><span style="color:#cccccc">.</span><span style="color:#f08d49">getLog</span><span style="color:#cccccc">(</span><span style="color:#f8c555">HelloController</span><span style="color:#cccccc">.</span><span style="color:#cc99cd">class</span><span style="color:#cccccc">)</span><span style="color:#cccccc">;</span>

        <span style="color:#cccccc">@Autowired</span>
        <span style="color:#cc99cd">private</span> <span style="color:#f8c555">DiscoveryClient</span> discoveryClient<span style="color:#cccccc">;</span>

        <span style="color:#cccccc">@RequestMapping</span><span style="color:#cccccc">(</span><span style="color:#7ec699">"/"</span><span style="color:#cccccc">)</span>
        <span style="color:#cc99cd">public</span> <span style="color:#f8c555">String</span> <span style="color:#f08d49">hello</span><span style="color:#cccccc">(</span><span style="color:#cccccc">)</span> <span style="color:#cccccc"></span>
                <span style="color:#cc99cd">return</span> <span style="color:#7ec699">"Hello World"</span><span style="color:#cccccc">;</span>
        <span style="color:#cccccc"></span>

        <span style="color:#cccccc">@RequestMapping</span><span style="color:#cccccc">(</span><span style="color:#7ec699">"/services"</span><span style="color:#cccccc">)</span>
        <span style="color:#cc99cd">public</span> <span style="color:#f8c555">List</span><span style="color:#cccccc"><</span><span style="color:#f8c555">String</span><span style="color:#cccccc">></span> <span style="color:#f08d49">services</span><span style="color:#cccccc">(</span><span style="color:#cccccc">)</span> <span style="color:#cccccc"></span>
                <span style="color:#cc99cd">return</span> <span style="color:#cc99cd">this</span><span style="color:#cccccc">.</span>discoveryClient<span style="color:#cccccc">.</span><span style="color:#f08d49">getServices</span><span style="color:#cccccc">(</span><span style="color:#cccccc">)</span><span style="color:#cccccc">;</span>
        <span style="color:#cccccc"></span>
<span style="color:#cccccc"></span>
</code></span></span>

现在真相大白了：部署到minikube上的pod，配置了探针地址是/health，但是服务中并没有此路径，因此探针检查一直无法通过；

解决问题

搞清楚问题之后就可以动手解决问题了，这里有两种解决方式：
第一种，修改HelloController.java，增加一个方法，对应的地址是/health的服务；
第二种，修改deployment的配置，将探针地址改为现有的服务，例如"/"，这是个可用的服务；

第一种方法很简单，留给读者您来完成吧，我们来试试第二种：

执行以下命令，开始编辑deployment：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell">kubectl edit deployment kubernetes-hello-world
</code></span></span>

在编辑页面上找到两个探针的配置，都从"/health"改成"/"，如下图两个红框所示：
修改完毕后，像普通vim操作一样"wq"保存退出，配置会立即生效，稍等一会儿再看pod情况，发现pod的name已经变了，并且状态已经成为Ready，证明旧的pod已经销毁，新的pod被创建并且探针测试通过：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">[</span>root@minikube examples<span style="color:#cccccc">]</span><span style="color:#999999"># kubectl get pods</span>
NAME                                      READY   STATUS    RESTARTS   AGE
kubernetes-hello-world-6c5f75ff74-dnm2q   <span style="color:#f08d49">1</span>/1     Running   <span style="color:#f08d49">0</span>          15s
</code></span></span>

访问地址http://192.168.121.133:30700 ，服务正常(192.168.121.133是宿主机IP地址)，如下图：

官方解释

官方的demo无法在minikube上正常运行，还要我们自己去修改配置或者源码，官方的demo不应该会这样，在kubernetes-hello-world-example工程内的README.md文档中发现了对此问题的说明，如下图红框所示，fabric8的maven插件在生成探针配置的是时候配错了URL，因此官方建议我们去修改deployment的配置，将探针的地址从"/health"改为"/actuator/heath"，这个问题已经被提交到了fabric8社区，并且贴出了链接：

权限问题

刚才我们看过了HelloController.java的源码，里面还有个路径为"/services"的接口，在minikube环境下访问此接口可以成功返回，内容是当前minikube环境的服务信息，但是如果部署在正式的kubernetes环境，访问此接口会返回以下错误：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell">Message: Forbidden<span style="color:#67cdcc">!</span>Configured <span style="color:#f08d49">service</span> account doesn't have access. Service account may have been revoked. services is forbidden: User <span style="color:#7ec699">"system:serviceaccount:default:default"</span> cannot list resource <span style="color:#7ec699">"services"</span> <span style="color:#cc99cd">in</span> API group <span style="color:#7ec699">""</span> <span style="color:#cc99cd">in</span> the namespace <span style="color:#7ec699">"default"</span>
</code></span></span>

也就是说当前的system:serviceaccount账号是没有权限通过API server访问"services"资源的，此时最快的解决办法是提升账号权限：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell">kubectl create clusterrolebinding permissive-binding <span style="color:#cccccc">\\</span>
  --clusterrole<span style="color:#67cdcc">=</span>cluster-admin <span style="color:#cccccc">\\</span>
  --user<span style="color:#67cdcc">=</span>admin <span style="color:#cccccc">\\</span>
  --user<span style="color:#67cdcc">=</span>kubelet <span style="color:#cccccc">\\</span>
  --group<span style="color:#67cdcc">=</span>system:serviceaccounts
</code></span></span>

注意：以上办法只能用于开发和测试环境，不要用在生产环境，在生产环境应该参考Kubernetes的RBAC授权相关设置来处理。

修改源码时遇到的错误怎么规避

如果您想尝试修改demo的源码并且部署上去，在编译阶段可能遇到以下问题：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#cccccc">[</span>root@minikube kubernetes-hello-world-example<span style="color:#cccccc">]</span><span style="color:#999999"># mvn clean package fabric8:deploy -Pkubernetes</span>
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Scanning <span style="color:#cc99cd">for</span> projects<span style="color:#cccccc">..</span>.
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ----------<span style="color:#67cdcc"><</span> org.springframework.cloud:kubernetes-hello-world <span style="color:#67cdcc">></span>----------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Building Spring Cloud Kubernetes :: Examples :: Hello World <span style="color:#f08d49">1.0</span>.1.RELEASE
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> --------------------------------<span style="color:#cccccc">[</span> jar <span style="color:#cccccc">]</span>---------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> --- maven-clean-plugin:2.5:clean <span style="color:#cccccc">(</span>default-clean<span style="color:#cccccc">)</span> @ kubernetes-hello-world ---
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Deleting /usr/local/work/demo/spring-cloud-kubernetes-1.0.1.RELEASE/spring-cloud-kubernetes-examples/kubernetes-hello-world-example/target
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> --- maven-checkstyle-plugin:3.0.0:check <span style="color:#cccccc">(</span>checkstyle-validation<span style="color:#cccccc">)</span> @ kubernetes-hello-world ---
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> 开始检查……
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> /usr/local/work/demo/spring-cloud-kubernetes-1.0.1.RELEASE/spring-cloud-kubernetes-examples/kubernetes-hello-world-example/src/main/java/org/springframework/cloud/kubernetes/examples/HelloController.java:33: 当前行匹配非法表达式： <span style="color:#7ec699">'Trailing whitespace'</span>。 <span style="color:#cccccc">[</span>Regexp<span style="color:#cccccc">]</span>
检查完成。
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> BUILD FAILURE
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Total time:  <span style="color:#f08d49">2.976</span> s
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> Finished at: <span style="color:#f08d49">2019</span>-06-08T22:15:37+08:00
<span style="color:#cccccc">[</span>INFO<span style="color:#cccccc">]</span> ------------------------------------------------------------------------
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> Failed to execute goal org.apache.maven.plugins:maven-checkstyle-plugin:3.0.0:check <span style="color:#cccccc">(</span>checkstyle-validation<span style="color:#cccccc">)</span> on project kubernetes-hello-world: Failed during checkstyle execution: There is <span style="color:#f08d49">1</span> error reported by Checkstyle <span style="color:#f08d49">8.12</span> with checkstyle.xml ruleset. -<span style="color:#67cdcc">></span> <span style="color:#cccccc">[</span>Help <span style="color:#f08d49">1</span><span style="color:#cccccc">]</span>
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> To see the full stack trace of the errors, re-run Maven with the -e switch.
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> Re-run Maven using the -X switch to <span style="color:#cc99cd">enable</span> full debug logging.
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> 
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> For <span style="color:#f08d49">more</span> information about the errors and possible solutions, please <span style="color:#cc99cd">read</span> the following articles:
<span style="color:#cccccc">[</span>ERROR<span style="color:#cccccc">]</span> <span style="color:#cccccc">[</span>Help <span style="color:#f08d49">1</span><span style="color:#cccccc">]</span> http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
</code></span></span>

出现上述问题的原因是maven-checkstyle-plugin插件检查代码的style没有通过，我试过在mvn命令中添加skip参数，也试过在pom.xml中添加maven-checkstyle-plugin节点并且配置为skip，结果都没有用，最终用以下方法成功规避了此问题：

打开pom.xml文件；
找到节点properties(如果没有就创建)，增加以下三个属性配置，这样配置的作用是在style检查失败、校验失败、单元测试代码检查失败这三种情况下，都不会导致整个maven构建的失败：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell"><span style="color:#67cdcc"><</span>properties<span style="color:#67cdcc">></span>
        <span style="color:#67cdcc"><</span>maven-checkstyle-plugin.failsOnError<span style="color:#67cdcc">></span>false<span style="color:#67cdcc"><</span>/maven-checkstyle-plugin.failsOnError<span style="color:#67cdcc">></span>
        <span style="color:#67cdcc"><</span>maven-checkstyle-plugin.failsOnViolation<span style="color:#67cdcc">></span>false<span style="color:#67cdcc"><</span>/maven-checkstyle-plugin.failsOnViolation<span style="color:#67cdcc">></span>
        <span style="color:#67cdcc"><</span>maven-checkstyle-plugin.includeTestSourceDirectory<span style="color:#67cdcc">></span>false<span style="color:#67cdcc"><</span>/maven-checkstyle-plugin.includeTestSourceDirectory<span style="color:#67cdcc">></span><span style="color:#67cdcc"><</span>/properties<span style="color:#67cdcc">></span>
</code></span></span>

至此，官方demo的部署和运行都完成了，对spring-cloud-kubernetes算是有了初步认识，接下来的实战中，我们一起去深入的了解spring-cloud-kubernetes，看看kubernetes上的springcloud应用怎么开发；

问题处理

感谢jason9211的提醒，如果读者您也遇到类似问题，请参考如下：

<span style="background-color:#2d2d2d"><span style="color:#cccccc"><code class="language-shell">如果在deploy时遇到 “the server could not <span style="color:#f08d49">find</span> the requested resource”问题，
建议把fabric8.maven.plugin的版本升级到4.2.0即可。 
<span style="color:#67cdcc"><</span>fabric8.maven.plugin.version<span style="color:#67cdcc">></span><span style="color:#f08d49">4.2</span>.<span style="color:#67cdcc"><span style="color:#cc99cd"><strong>0</strong></span><</span>/fabric8.maven.plugin.version<span style="color:#67cdcc">></span></code></span></span>

点击关注，第一时间了解华为云新鲜技术~

以上是关于想了解 spring-cloud-kubernetes，那就先来实战一把官方demo的主要内容，如果未能解决你的问题，请参考以下文章

spring-cloud-kubernetes与SpringCloud Gateway

#yyds干货盘点#spring-cloud-kubernetes与SpringCloud Gateway

部署 spring-cloud-kubernetes kubernetes-hello-world-example 失败

存在 spring-cloud-kubernetes 配置映射依赖项的 spring 应用程序启动异常

spring-cloud-kubernetes官方demo运行实战

#yyds干货盘点#spring-cloud-kubernetes官方demo运行实战