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<title>135. DiscoveryClient for Kubernetes</title><link rel="stylesheet" type="text/css" href="css/manual-multipage.css"><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="multi_spring-cloud.html" title="Spring Cloud"><link rel="up" href="multi__spring_cloud_kubernetes.html" title="Part XVII. Spring Cloud Kubernetes"><link rel="prev" href="multi__why_do_you_need_spring_cloud_kubernetes.html" title="134. Why do you need Spring Cloud Kubernetes?"><link rel="next" href="multi__kubernetes_native_service_discovery.html" title="136. Kubernetes native service discovery"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">135. DiscoveryClient for Kubernetes</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="multi__why_do_you_need_spring_cloud_kubernetes.html">Prev</a> </td><th width="60%" align="center">Part XVII. Spring Cloud Kubernetes</th><td width="20%" align="right"> <a accesskey="n" href="multi__kubernetes_native_service_discovery.html">Next</a></td></tr></table><hr></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a name="_discoveryclient_for_kubernetes" href="#_discoveryclient_for_kubernetes"></a>135. DiscoveryClient for Kubernetes</h2></div></div></div><p>This project provides an implementation of <a class="link" href="https://github.com/spring-cloud/spring-cloud-commons/blob/master/spring-cloud-commons/src/main/java/org/springframework/cloud/client/discovery/DiscoveryClient.java" target="_top">Discovery Client</a>
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for <a class="link" href="http://kubernetes.io" target="_top">Kubernetes</a>.
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This allows you to query Kubernetes endpoints <span class="strong"><strong>(see <a class="link" href="http://kubernetes.io/docs/user-guide/services/" target="_top">services</a>)</strong></span> by name.
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A service is typically exposed by the Kubernetes API server as a collection of endpoints which represent <code class="literal">http</code>, <code class="literal">https</code> addresses that a client can
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access from a Spring Boot application running as a pod. This discovery feature is also used by the Spring Cloud Kubernetes Ribbon project
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to fetch the list of the endpoints defined for an application to be load balanced.</p><p>This is something that you get for free just by adding the following dependency inside your project:</p><pre class="programlisting"><span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"><dependency></span>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"><groupId></span>org.springframework.cloud<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"></groupId></span>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"><artifactId></span>spring-cloud-starter-kubernetes<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"></artifactId></span>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"><version></span>${latest.version}<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"></version></span>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-tag"></dependency></span></pre><p>To enable loading of the <code class="literal">DiscoveryClient</code>, add <code class="literal">@EnableDiscoveryClient</code> to the according configuration or application class like this:</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@SpringBootApplication</span></em>
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<em><span class="hl-annotation" style="color: gray">@EnableDiscoveryClient</span></em>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span> Application {
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">static</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">void</span> main(String[] args) {
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SpringApplication.run(Application.<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span>, args);
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}
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}</pre><p>Then you can inject the client in your code simply by:</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@Autowired</span></em>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">private</span> DiscoveryClient discoveryClient;</pre><p>If for any reason you need to disable the <code class="literal">DiscoveryClient</code> you can simply set the following property in <code class="literal">application.properties</code>:</p><pre class="screen">spring.cloud.kubernetes.discovery.enabled=false</pre><p>Some Spring Cloud components use the <code class="literal">DiscoveryClient</code> in order to obtain info about the local service instance. For
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this to work you need to align the Kubernetes service name with the <code class="literal">spring.application.name</code> property.</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="multi__why_do_you_need_spring_cloud_kubernetes.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="multi__spring_cloud_kubernetes.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="multi__kubernetes_native_service_discovery.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">134. Why do you need Spring Cloud Kubernetes? </td><td width="20%" align="center"><a accesskey="h" href="multi_spring-cloud.html">Home</a></td><td width="40%" align="right" valign="top"> 136. Kubernetes native service discovery</td></tr></table></div></body></html> |