Spring Boot实战系列(7)集成Consul配置中心

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本篇主要介绍了 Spring Boot 如何与 Consul 进行集成，Consul 只是服务注册的一种实现，还有其它的例如 Zookeeper、Etcd 等，服务注册发现在微服务架构中扮演这一个重要的角色，伴随着服务的大量出现，服务与服务之间的配置管理、运维管理也变的难以维护，通过 Consul 可以解决这些问题，实现服务治理、服务监控。

关于 Consul 的更多知识点不在这里赘述，但是在学习本节之前还是希望您能先了解下，请移步我之前写的 微服务服务注册发现之 Consul 系列

快速导航

• 添加 Consul Maven依赖
• 系统级配置文件&应用级配置文件
• 配置Consul管理控制台
• 项目构建
  • 建立Config获取Consul配置数据
  • 编写启动类调用配置
• 接口测试
• 总结

注意：以下代码示例可在Github查看项目完整示例 chapter7-1

添加maven依赖

在 Spring Boot 项目的 pom.xml 文件中引入 spring-cloud-starter-consul-discovery 启动器

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-discovery</artifactId>
    <version>2.1.1.RELEASE</version>
</dependency>

使用 Consul 配置信息时需要引入 spring-cloud-starter-consul-config 依赖

 <dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>
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配置文件

系统级配置文件 bootstrap.yml

使用 Spring Cloud Consul Config，需要配置以下信息在 bootstrap.yml 文件

• spring.cloud.consul.host：配置consul地址
• spring.cloud.consul.port：配置consul端口
• spring.cloud.consul.config.prefix：配置基本文件，默认值config
• spring.cloud.consul.config.enabled：启动consul配置中心
• spring.cloud.consul.config.format：consul上面文件的格式 YAML、FILES、PROPERTIES、默认 KEY-VALUE
• spring.cloud.consul.config.data-key：表示 consul 上面的 KEY 值(或者说文件的名字)，默认是 data

bootstrap.yml

spring:
  cloud:
    consul:
      host: 192.168.6.128
      port: 8500
      config:
        prefix: config
        enabled: true
        format: YAML
        data-key: user
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应用级配置文件 application.yml

定义应用级别的配置在 bootstrap.yml 之后加载，例如搭配 spring-cloud-config 使用。

• spring.cloud.consul.host：配置consul地址
• spring.cloud.consul.port：配置consul端口
• spring.cloud.consul.discovery.enabled：启用服务发现
• spring.cloud.consul.discovery.register：启用服务注册
• spring.cloud.consul.discovery.deregister：服务停止时取消注册
• spring.cloud.consul.discovery.prefer-ip-address：表示注册时使用IP而不是hostname
• spring.cloud.consul.discovery.health-check-interval：健康检查频率
• spring.cloud.consul.discovery.health-check-path：健康检查路径
• spring.cloud.consul.discovery.health-check-critical-timeout：健康检查失败多长时间后，取消注册
• spring.cloud.consul.discovery.instance-id：服务注册标识

server:
  port: 8082
spring:
  application:
    name: consul-service
  profiles:
    active: dev
  cloud:
    consul:
      host: 192.168.6.128
      port: 8500
      discovery: # 服务发现配置
        enabled: true
        register: true
        deregister: true
        prefer-ip-address: true
        health-check-interval: 10s
        health-check-critical-timeout: 30s
        health-check-path: /health
        instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${server.port} # 应用名称+服务器IP+端口
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配置Consul管理控制台

Consul 提供了 Key/Value 存储用于存储配置数据，在 Spring Cloud Consul 中配置默认存储于 /config 文件夹下，根据应用程序名和模拟 Spring Cloud Config 顺序解析属性的规则来配置文件。

在本例中操作 Consul 管控台建立以下路径配置：

• config：为配置基本文件，这里默认为 config。
• consul-service：为 application.yml 中配置的 spring.application.name 值。
• dev：为 application.yml 中配置的 spring.profiles.active 值，也是本程序设置环境变量意为开发环境。
• user.yml：为配置的文件名，格式为 yml 格式。

config/consul-service.dev/user.yml
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最终为 Consul 管控台建立的配置数据如下图所示：

项目构建

注意：以下只贴核心代码，源码参见：Github chapter7-1

建立Config获取Consul配置数据

• 获取student配置数据

注意以下属性名要与在 Consul 管控台中配置的一一对应。

@ConfigurationProperties 进行属性注入

config/StudentConfig.java

@ConfigurationProperties(prefix = "student")
public class StudentConfig {
    private String name;
    private int age;
<span class="token keyword">public</span> String <span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> name<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">setName</span><span class="token punctuation">(</span>String name<span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span>name <span class="token operator">=</span> name<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">getAge</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> age<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">setAge</span><span class="token punctuation">(</span><span class="token keyword">int</span> age<span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span>age <span class="token operator">=</span> age<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> String <span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> <span class="token string">"大家好我是"</span> <span class="token operator">+</span> name <span class="token operator">+</span> <span class="token string">"，今年"</span> <span class="token operator">+</span> age <span class="token operator">+</span> <span class="token string">"岁，我是一名在校大学生！"</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

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• 获取teach配置数据

同以上 student 配置，我们可以将不同类型的配置分文件进行配置定义

@ConfigurationProperties(prefix = "teach")
public class TeachConfig {
    private String name;
    private String course;
<span class="token keyword">public</span> String <span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> name<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">setName</span><span class="token punctuation">(</span>String name<span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span>name <span class="token operator">=</span> name<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> String <span class="token function">getCourse</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> course<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">setCourse</span><span class="token punctuation">(</span>String course<span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">this</span><span class="token punctuation">.</span>course <span class="token operator">=</span> course<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@Override</span>
<span class="token keyword">public</span> String <span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> <span class="token string">"大家好我是"</span> <span class="token operator">+</span> name <span class="token operator">+</span> <span class="token string">"，是一名大学老师！教同学们学习"</span> <span class="token operator">+</span> course<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

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编写启动类调用配置

注解说明：

• EnableDiscoveryClient：让注册中心进行服务发现，将服务注册到服务组件上。
• RestController：是 @ResponseBody 和 @Controller 注解的组合，注明该注解后整个类所有的方法返回值为json格式。
• SpringBootApplication：SpringBoot 的启动注解。
• EnableConfigurationProperties：属性配置的 class 添加到 SpringBoot 的属性配置注解里，否则不能通过 @Autowired 注解注入我们定义的属性配置类。

接口说明：

• /health：健康检查接口
• /user/description：@Value 注解获取用户信息描述接口
• /user/student/intro：@ConfigurationProperties 获取学生简介信息接口
• /user/teach/intro：@ConfigurationProperties 获取教师简介信息接口

@EnableDiscoveryClient
@RestController
@SpringBootApplication
@EnableConfigurationProperties({ StudentConfig.class, TeachConfig.class })
public class ConsulApplication {
<span class="token annotation punctuation">@Value</span><span class="token punctuation">(</span><span class="token string">"${description}"</span><span class="token punctuation">)</span>
<span class="token keyword">private</span> String description<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Autowired</span>
<span class="token keyword">private</span> StudentConfig studentConfig<span class="token punctuation">;</span>

<span class="token annotation punctuation">@Autowired</span>
<span class="token keyword">private</span> TeachConfig teachConfig<span class="token punctuation">;</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/health"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">Health</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"health"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">return</span> <span class="token string">"OK"</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/user/description"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">Description</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> description<span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/user/student/intro"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">StudentIntro</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> studentConfig<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/user/teach/intro"</span><span class="token punctuation">)</span>
<span class="token keyword">public</span> String <span class="token function">TeachIntro</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> teachConfig<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

<span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">main</span><span class="token punctuation">(</span>String<span class="token punctuation">[</span><span class="token punctuation">]</span> args<span class="token punctuation">)</span> <span class="token punctuation">{</span>
    SpringApplication<span class="token punctuation">.</span><span class="token function">run</span><span class="token punctuation">(</span>ConsulApplication<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">,</span> args<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>

}

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接口测试

• 健康检查接口

该接口在服务启动后且向 Consul 配置中心注册后，根据 application.yml 文件配置的 health-check-interval 和 health-check-path属性进行自动调用。

$ curl http://127.0.0.1:8082/health
OK!

注册成功后展示我们服务的名称及健康检查结果如下：

• 获取教师简介配置接口

$ curl http://127.0.0.1:8082/user/teach/intro
大家好我是Teach Li，是一名大学老师！教同学们学习Java软件开发!
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• 获取学生简介配置接口

$ curl http://127.0.0.1:8082/user/student/intro
大家好我是Jack，今年18岁，我是一名在校大学生！
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• 采用 @Value 注解获取项目描述接口

$ curl http://127.0.0.1:8082/user/description
用户信息描述
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总结

这里我们只介绍了 Consul 在 Spring Boot 的配置功能，关于 Consul 做为注册中心在下一章节中介绍，本篇中需要注意通过 @Value 注入的属性，修改 Consul 后需要重启服务才能生效，通过 @ConfigurationProperties 注入的属性，在 Consul 管控台修改属性之后可立即生效。

如遇到其他什么可在SpringBoot-Course issues中提问

资料

• 个人博客： Node.js技术栈
• Spring Boot 实战系列：https://github.com/Q-Angelo/SpringBoot-Course
• 项目源码： Github查看本文完整示例 chapter7-1