详解使用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：https://www.jb51.net/article/141789.htm

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

<dependencyManagement>
  <dependencies>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-consul-dependencies</artifactId>
      <version>1.0.1.RELEASE</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement> 

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-actuator</artifactId>
    <version>1.3.5.RELEASE</version>
  </dependency>
  <dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-discovery</artifactId>
  </dependency>
</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

package com.pp.consul1; 

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; 

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulApp { 

  @RequestMapping("/home")
  public Object home() {
    System.out.println("1111111111111");
    return "OK11";
  } 

  public static void main( String[] args ) {
    SpringApplication.run(ConsulApp.class, args);
  }
}

application.properties 配置内容

server.port=9955
spring.application.name=Consul-Server-1
spring.cloud.consul.host=192.168.1.100
spring.cloud.consul.port=8500
spring.cloud.consul.enabled=true
spring.cloud.consul.discovery.enabled=true
spring.cloud.consul.discovery.instanceId=tomcat1
spring.cloud.consul.discovery.serviceName=tomcat
spring.cloud.consul.discovery.hostname=192.168.2.95
spring.cloud.consul.discovery.port=${server.port}
spring.cloud.consul.discovery.healthCheckUrl=http://192.168.2.95:9955/health
spring.cloud.consul.discovery.healthCheckInterval=10s
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：

{
  "Node":"192.168.1.100",
  "Address":"192.168.1.100",
  "ServiceID":"tomcat1",
  "ServiceName":"tomcat",
  "ServiceTags":["dev"],
  "ServiceAddress":"192.168.2.95",
  "ServicePort":9955,
  "ServiceEnableTagOverride":false,
  "CreateIndex":993,
  "ModifyIndex":1057
}

二：服务端2

项目依赖和上面一样

package com.pp.consul2;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; 

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulApp { 

  @RequestMapping("/home")
  public Object home() {
    System.out.println("2222222222222222");
    return "OK22";
  } 

  public static void main( String[] args ) {
    SpringApplication.run(ConsulApp.class, args);
  }
}

application.properties 配置内容：

server.port=9966 

spring.application.name=Consul-Server-2
spring.cloud.consul.host=192.168.1.100
spring.cloud.consul.port=8500
spring.cloud.consul.enabled=true
spring.cloud.consul.discovery.enabled=true
spring.cloud.consul.discovery.instanceId=tomcat2
spring.cloud.consul.discovery.serviceName=tomcat
spring.cloud.consul.discovery.hostname=192.168.2.95
spring.cloud.consul.discovery.port=${server.port}
spring.cloud.consul.discovery.healthCheckUrl=http://192.168.2.95:9966/health
spring.cloud.consul.discovery.healthCheckInterval=10s
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：

server.port=9977 

spring.application.name=Consul-Client
spring.cloud.consul.host=192.168.1.100
spring.cloud.consul.port=8500
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

package com.pp.client; 

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; 

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulClient { 

  @Autowired
  private LoadBalancerClient loadBalancer; 

  @Autowired
  private DiscoveryClient discoveryClient; 

  /**
   * 从所有服务中选择一个服务（轮询）
   */
  @RequestMapping("/discover")
  public Object discover() {
    return loadBalancer.choose("tomcat").getUri().toString();
  } 

  /**
   * 获取所有服务
   */
  @RequestMapping("/services")
  public Object services() {
    return discoveryClient.getInstances("tomcat");
  } 

  public static void main( String[] args ) {
    SpringApplication.run(ConsulClient.class, args);
  }
}

启动之后，就可以访问/discover，/services 查看效果了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。