使用Spring Cloud Consul实现服务的注册和发现

首先安装consul环境，参照之前的文章：http://blog.youkuaiyun.com/mn960mn/article/details/51753893

项目规划，2个服务端，1个客户端

首先来看服务端，

一：服务端1：

项目依赖

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1. <dependencyManagement>  
2.     <dependencies>  
3.         <dependency>  
4.             <groupId>org.springframework.cloud</groupId>  
5.             <artifactId>spring-cloud-consul-dependencies</artifactId>  
6.             <version>1.0.1.RELEASE</version>  
7.             <type>pom</type>  
8.             <scope>import</scope>  
9.         </dependency>  
10.     </dependencies>  
11. </dependencyManagement>  
12.   
13. <dependencies>  
14.     <dependency>  
15.         <groupId>org.springframework.boot</groupId>  
16.         <artifactId>spring-boot-actuator</artifactId>  
17.         <version>1.3.5.RELEASE</version>  
18.     </dependency>  
19.     <dependency>  
20.         <groupId>org.springframework.cloud</groupId>  
21.         <artifactId>spring-cloud-starter-consul-discovery</artifactId>  
22.     </dependency>  
23. </dependencies>  

注意，增加spring-boot-actuator是为了项目可以访问/health 路径来判断服务是否健康

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1. package com.pp.consul1;  
2.   
3. import org.springframework.boot.SpringApplication;  
4. import org.springframework.boot.autoconfigure.SpringBootApplication;  
5. import org.springframework.cloud.client.discovery.EnableDiscoveryClient;  
6. import org.springframework.web.bind.annotation.RequestMapping;  
7. import org.springframework.web.bind.annotation.RestController;  
8.   
9. @SpringBootApplication  
10. @EnableDiscoveryClient  
11. @RestController  
12. public class ConsulApp {  
13.       
14.     @RequestMapping("/home")  
15.     public Object home() {  
16.         System.out.println("1111111111111");  
17.         return "OK11";  
18.     }  
19.       
20.     public static void main( String[] args ) {  
21.         SpringApplication.run(ConsulApp.class, args);  
22.     }  
23. }  

application.properties 配置内容

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1. server.port=9955  
2.   
3. spring.application.name=Consul-Server-1  
4. spring.cloud.consul.host=192.168.1.100  
5. spring.cloud.consul.port=8500  
6. spring.cloud.consul.enabled=true  
7. spring.cloud.consul.discovery.enabled=true  
8. spring.cloud.consul.discovery.instanceId=tomcat1  
9. spring.cloud.consul.discovery.serviceName=tomcat  
10. spring.cloud.consul.discovery.hostname=192.168.2.95  
11. spring.cloud.consul.discovery.port=${server.port}  
12. spring.cloud.consul.discovery.healthCheckUrl=http://192.168.2.95:9955/health  
13. spring.cloud.consul.discovery.healthCheckInterval=10s  
14. spring.cloud.consul.discovery.tags=dev  

看过我之前文章的，应该对这些配置很清楚了。这样，一个服务端就配置写好了。

由于我们增加了@EnableDiscoveryClient注解，所以，系统启动的时候，就会向consul注册一个服务，服务的名字为tomcat, ID为tomcat1

访问consul的HTTP API /v1/catalog/service/tomcat 输出如下：

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1. {  
2.     "Node":"192.168.1.100",  
3.     "Address":"192.168.1.100",  
4.     "ServiceID":"tomcat1",  
5.     "ServiceName":"tomcat",  
6.     "ServiceTags":["dev"],  
7.     "ServiceAddress":"192.168.2.95",  
8.     "ServicePort":9955,  
9.     "ServiceEnableTagOverride":false,  
10.     "CreateIndex":993,  
11.     "ModifyIndex":1057  
12. }  

二：服务端2

项目依赖和上面一样

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1. package com.pp.consul2;  
2.   
3. import org.springframework.boot.SpringApplication;  
4. import org.springframework.boot.autoconfigure.SpringBootApplication;  
5. import org.springframework.cloud.client.discovery.EnableDiscoveryClient;  
6. import org.springframework.web.bind.annotation.RequestMapping;  
7. import org.springframework.web.bind.annotation.RestController;  
8.   
9. @SpringBootApplication  
10. @EnableDiscoveryClient  
11. @RestController  
12. public class ConsulApp {  
13.       
14.     @RequestMapping("/home")  
15.     public Object home() {  
16.         System.out.println("2222222222222222");  
17.         return "OK22";  
18.     }  
19.       
20.     public static void main( String[] args ) {  
21.         SpringApplication.run(ConsulApp.class, args);  
22.     }  
23. }  

application.properties 配置内容：

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1. server.port=9966  
2.   
3. spring.application.name=Consul-Server-2  
4. spring.cloud.consul.host=192.168.1.100  
5. spring.cloud.consul.port=8500  
6. spring.cloud.consul.enabled=true  
7. spring.cloud.consul.discovery.enabled=true  
8. spring.cloud.consul.discovery.instanceId=tomcat2  
9. spring.cloud.consul.discovery.serviceName=tomcat  
10. spring.cloud.consul.discovery.hostname=192.168.2.95  
11. spring.cloud.consul.discovery.port=${server.port}  
12. spring.cloud.consul.discovery.healthCheckUrl=http://192.168.2.95:9966/health  
13. spring.cloud.consul.discovery.healthCheckInterval=10s  
14. spring.cloud.consul.discovery.tags=test  

三：客户端

项目依赖，只需要spring-cloud-starter-consul-discovery

application.properties 配置内容：

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1. server.port=9977  
2.   
3. spring.application.name=Consul-Client  
4. spring.cloud.consul.host=192.168.1.100  
5. spring.cloud.consul.port=8500  
6. spring.cloud.consul.discovery.register=false  

注意，这里的spring.cloud.consul.discovery.register需要配置成false，否则系统启动的时候，会向consul注册一个服务

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1. package com.pp.client;  
2.   
3. import org.springframework.beans.factory.annotation.Autowired;  
4. import org.springframework.boot.SpringApplication;  
5. import org.springframework.boot.autoconfigure.SpringBootApplication;  
6. import org.springframework.cloud.client.discovery.DiscoveryClient;  
7. import org.springframework.cloud.client.discovery.EnableDiscoveryClient;  
8. import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;  
9. import org.springframework.web.bind.annotation.RequestMapping;  
10. import org.springframework.web.bind.annotation.RestController;  
11.   
12. @SpringBootApplication  
13. @EnableDiscoveryClient  
14. @RestController  
15. public class ConsulClient  {  
16.       
17.     @Autowired  
18.     private LoadBalancerClient loadBalancer;  
19.       
20.     @Autowired  
21.     private DiscoveryClient discoveryClient;  
22.       
23.     /** 
24.      * 从所有服务中选择一个服务（轮询） 
25.      */  
26.     @RequestMapping("/discover")  
27.     public Object discover() {  
28.         return loadBalancer.choose("tomcat").getUri().toString();  
29.     }  
30.       
31.     /** 
32.      * 获取所有服务  
33.      */  
34.     @RequestMapping("/services")  
35.     public Object services() {  
36.         return discoveryClient.getInstances("tomcat");  
37.     }  
38.       
39.     public static void main( String[] args ) {  
40.         SpringApplication.run(ConsulClient.class, args);  
41.     }  
42. }  

启动之后，就可以访问/discover，/services 查看效果了。