服务注册发现consul之二：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：《spring cloud consul介绍》中的第一节介绍。

为了演示consul的注册与发现，下面会创建2个服务和1个client端：

一：服务端1：

1、pom.xml

<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>

<groupId>com.dxz</groupId>
<artifactId>cloud-server1</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>cloud-client</name>
<url>http://maven.apache.org</url>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>

<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Dalston.RELEASE</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>

server的启动类：ConsulApp.java

package com.dxz.cloud_server;

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("cloud-server1");
return "cloud-server1";
}

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

配置文件application.properties

spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.healthCheckPath=${management.contextPath}/health
spring.cloud.consul.discovery.healthCheckInterval=15s
spring.cloud.consul.discovery.instance-id=consul-server1
spring.application.name=consul-server
server.port=8503

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consul-server, ID为consul-server1

启动后，访问：http://localhost:8500/ui/#/dc1/services/consul-server，输出如下页面：



访问consul的HTTP API：http://localhost:8500/v1/catalog/service/consul-server 输出如下：

[
{
"ID": "ae2b2853-18fa-7042-a157-25da30fcc744",
"Node": "DESKTOP-PPSFCNC",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"wan": "127.0.0.1"
},
"NodeMeta": {},
"ServiceID": "consul-server1",
"ServiceName": "consul-server",
"ServiceTags": [],
"ServiceAddress": "DESKTOP-PPSFCNC",
"ServicePort": 8503,
"ServiceEnableTagOverride": false,
"CreateIndex": 316,
"ModifyIndex": 719
},
{
"ID": "ae2b2853-18fa-7042-a157-25da30fcc744",
"Node": "DESKTOP-PPSFCNC",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"wan": "127.0.0.1"
},
"NodeMeta": {},
"ServiceID": "consul-server2",
"ServiceName": "consul-server",
"ServiceTags": [],
"ServiceAddress": "DESKTOP-PPSFCNC",
"ServicePort": 8504,
"ServiceEnableTagOverride": false,
"CreateIndex": 585,
"ModifyIndex": 721
}
]

二：服务端2

1、pom.xml同上

2、启动类：

package com.dxz.cloud_server;

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("cloud-server2");
return "cloud-server2";
}

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

application.properties 配置内容：（端口、instance-id不同）

spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.healthCheckPath=${management.contextPath}/health
spring.cloud.consul.discovery.healthCheckInterval=15s
spring.cloud.consul.discovery.instance-id=consul-server2
spring.application.name=consul-server
server.port=8504

启动后：



三：客户端

项目依赖，只需要spring-cloud-starter-consul-discovery（我的pom同上）

application.properties 配置内容：

spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.healthCheckPath=${management.contextPath}/health
spring.cloud.consul.discovery.healthCheckInterval=15s
spring.cloud.consul.discovery.instance-id=consul-client1
spring.application.name=consul-client1
server.port=8501

主类：

package com.dxz.cloud_client;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
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 ConsulClientApplication {

@RequestMapping("/home")
public String home() {
return "hi ,i'm consul client";
}

public static void main(String[] args) {
new SpringApplicationBuilder(ConsulClientApplication.class).web(true).run(args);
}
}

主类：ConsulClientApplication.java

package com.dxz.cloud_client;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
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 ConsulClientApplication {

@RequestMapping("/home")
public String home() {
return "hi ,i'm consul client";
}

@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("consul-server").getUri().toString();
}

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

public static void main(String[] args) {
new SpringApplicationBuilder(ConsulClientApplication.class).web(true).run(args);
}
}

启动之后,观看consul如下：



访问http://localhost:8501/services返回如下：

[{"serviceId":"consul-server","host":"DESKTOP-PPSFCNC","port":8503,"secure":false,"metadata":{},"uri":"http://DESKTOP-PPSFCNC:8503"},{"serviceId":"consul-server","host":"DESKTOP-PPSFCNC","port":8504,"secure":false,"metadata":{},"uri":"http://DESKTOP-PPSFCNC:8504"}]

访问：http://localhost:8501/discover