Consul简介:一款适用于分布式系统下服务发现和配置的开源工具,支持服务健康检查、key/value数据存储、分布一致性实现、多数据中心方案,并且内置服务注册和发现框架,支持Spring Cloud集成。
实现准备:
1.Consul独立下载安装:https://www.consul.io/downloads.html
2.解压后只有一个简单的consul.exe可执行文件,同级目录下执行consul agent -dev启动consul服务端即可,在浏览器中输入地址:http://localhost:8500,看到consul界面则表示安装成功
3.使用版本:springboot使用2.1.5.RELEASE版本、consul依赖使用2.1.1.RELEASE版本
4.新建两个SpringBoot项目,模拟服务提供者和消费者:consul-provider和consul-consumer
代码实现:
1.在consul-provider中,首先在pom中引入Spring Cloud支持和consul相关依赖:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.ccl</groupId>
<artifactId>consul-provider</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>consul-provider</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!-- springmvc -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 支持健康检查 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!-- Consul-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
<version>2.1.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<!-- spring cloud -->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependendies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
然后在application.yml中配置服务端consul:
server:
port: 8019
servlet:
context-path: /consulProvider
spring:
application:
name: order-service # 应用服务名称
cloud:
consul:
host: 127.0.0.1 # Consul所在ip
port: 8500 # Consul监听端口
discovery:
register: true # 配置服务注册到Consul
healthCheckPath: ${server.servlet.context-path}/health # 配置Consul实例的服务健康检查地址,默认为/health,使用非默认上下文路径也应修改这里
healthCheckInterval: 2s # Consul健康检查频率,也叫心跳频率
instance-id: ${spring.application.name} # 配置注册到Consul的服务id
service-name: ${spring.application.name}
tags: urlprefis-/${spring.application.name}
新建HealthCheckController添加consul需要调用的健康检查接口。为了方便把提供服务的方法也写在这里。
package com.ccl.consulprovider.Controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;
import java.util.List;
/**
* 健康检查接口
*/
@RestController
public class HealthCheckController {
// 改路径需要和配置文件中健康检查地址保持一致
@RequestMapping("/health")
public String healthCheck(){
return "ok";
}
/**
* 模拟提供服务的方法
*/
@RequestMapping("/services")
public Object services(String param1,String param2){
List<String> pList = new ArrayList<>();
pList.add(param1);
pList.add(param2);
// 模拟业务代码...
return pList;
}
}
同时在开启类上添加@EnableDiscoveryClient注解,支持向Consul注册服务:
package com.ccl.consulprovider;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@SpringBootApplication
@EnableDiscoveryClient // 自动加载服务注册、心跳检测等配置
public class ConsulProviderApplication {
public static void main(String[] args) {
SpringApplication.run(ConsulProviderApplication.class, args);
}
}
启动consul-provider成功后,浏览器输入localhost:8500可以看到order-service,表示服务注册成功。
2.在consul-consumer中,pom配置和consul-provider一致即可
在application.yml添加客户端配置:
spring:
application:
name: service-client
cloud:
consul:
host: localhost # consul服务端
port: 8500 # consul服务端监听端口
discovery:
register: false # 不需要注册到consul上
server:
port: 8020
注意:实际项目中如果consul-consumer也向其他项目提供服务的话,也需要和consul-provider中有类似配置。这里spring.cloud.consul.discovery.register置为false表示不向consul提供服务,所以主类上@EnableDiscoveryClient注解也可省略。
package com.ccl.consulconsumer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@SpringBootApplication
@EnableDiscoveryClient // 已配置spring.cloud.consul.discovery.register=false,客户端不向consul注册服务,这个注解也可省略
public class ConsulConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(ConsulConsumerApplication.class, args);
}
}
新建ApiController访问consul中服务:
package com.ccl.consulconsumer.controller;
import com.ccl.consulconsumer.domain.OrderEntity;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import java.util.List;
@RestController
@RequestMapping("/api")
public class ApiController {
@Autowired
private LoadBalancerClient loadBalancerClient;
@Autowired
private DiscoveryClient discoveryClient;
@RequestMapping("/getServiceInfo")
public Object getServiceInfo(){
ServiceInstance serviceInstance = loadBalancerClient.choose("order-service"); // 服务Id
System.out.println(serviceInstance);
String url = "http://"+serviceInstance.getHost()+":"+serviceInstance.getPort()
+"/consulProvider/services?param1={1}¶m2={2}";
return new RestTemplate().getForObject(url, List.class, "hello p1","hello p2");
}
/**
* 从所有服务中选择一个服务
*/
@RequestMapping("/discover")
public Object discover(){
return loadBalancerClient.choose("order-service").getUri().toString();
}
/**
* 获取所有服务
*/
@RequestMapping("/services")
public Object services(){
List<ServiceInstance> services = discoveryClient.getInstances("order-service");
return services;
}
}
开启consul-consumer成功后,在浏览器中分别输入:
http://localhost:8020/api/services
http://localhost:8020/api/discover
http://localhost:8020/api/getServiceInfo
界面分别如下:
[{
"instanceId": "order-service",
"serviceId": "order-service",
"host": "DESKTOP-EPG1K4Q",
"port": 8019,
"secure": false,
"metadata": {
"urlprefis-/order-service": "urlprefis-/order-service",
"secure": "false",
"contextPath": "/consulProvider"
},
"uri": "http://DESKTOP-EPG1K4Q:8019",
"scheme": null
}]
http://DESKTOP-EPG1K4Q:8019
["hello p1","hello p2"]
此时就实现了Spring Cloud Consul服务注册、发现,这里只描述了单个消费者和单个服务提供者的例子,如果涉及到多服务集群的需求,参照consul-provider并修改相关host/port以及服务名称、访问路径等配置即可。
更多关于consul的详细资料,可参看这里。