Spring Cloud学习--Spring Cloud Consul服务注册与发现

妖狐艹你老母 2022-05-26 10:51 261阅读 0赞

之前我们已经在几篇博客中介绍了以Eureka为注册中心服务注册与发现机制，接下来我们学习了解一下以Consul为注册中心的服务注册与发现。

#### Consul简介 ####

Consul 是 HashiCorp 公司推出的开源工具，用于实现分布式系统的服务发现与配置。与其他分布式服务注册与发现的方案，Consul的方案更“一站式”，内置了服务注册与发现框 架、分布一致性协议实现、健康检查、Key/Value存储、多数据中心方案，不再需要依赖其他工具（比如ZooKeeper等）。使用起来也较 为简单。Consul使用Go语言编写，因此具有天然可移植性(支持Linux、windows和Mac OS X)；安装包仅包含一个可执行文件，方便部署，与Docker等轻量级容器可无缝配合 。

1、Consul 下载地址：[https://www.consul.io/downloads.html][https_www.consul.io_downloads.html]

2、执行如下命令启动Consul：consul agent -dev

![70][]

3、在浏览器中打开consul提供的管理页面

![70 1][]

#### Consul 服务提供者 ####

服务提供者将服务信息注册到注册中心consul，在工程的application.yml中需要添加consul相关的地址信息

1、pom.xml引入consul相关jar

<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">
    	<parent>
    	    <groupId>org.springframework.boot</groupId>
    	    <artifactId>spring-boot-starter-parent</artifactId>
    	    <version>1.5.10.RELEASE</version>
    	</parent>
    	
    	<dependencyManagement>
    	    <dependencies>
    	        <dependency>
    	            <groupId>org.springframework.cloud</groupId>
    	            <artifactId>spring-cloud-dependencies</artifactId>
    	            <version>Edgware.SR3</version>
    	            <type>pom</type>
    	            <scope>import</scope>
    	        </dependency>
    	    </dependencies>
    	</dependencyManagement>
    	<modelVersion>4.0.0</modelVersion>
    	<groupId>com.tianjunwei</groupId>
    	<artifactId>TJWspringCloud-consul</artifactId>
    	<version>1.0.0-SNAPSHOT</version>
    	<packaging>jar</packaging>
    	<name>TJWspringCloud-consul</name>
    	<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>ch.qos.logback</groupId>  
                <artifactId>logback-core</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-classic</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-access</artifactId>  
            </dependency>  
    	</dependencies>
    	<build>
    		<resources>
    			<resource>
    				<directory>src/main/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/test/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/main/resources</directory>
    				<includes>
    					<include>**/*.*</include>
    				</includes>
    			</resource>
    		</resources>
    		<plugins>  
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    			
    	        <plugin>  
    	            <groupId>org.apache.maven.plugins</groupId>  
    	            <artifactId>maven-compiler-plugin</artifactId>  
    	            <version>2.0.2</version>  
    	            <configuration>  
    	                <source>1.8</source>  
    	                <target>1.8</target>  
    	            </configuration>  
    	        </plugin>  
    	    </plugins>  
    	</build>
    </project>

2、application.yml中添加相关配置

spring:
      cloud:
        consul:
    #consul地址
          host: localhost  
    #consul 对外提供服务的端口
          port: 8500
          discovery:
    #服务提供者对外提供的健康检查接口
            healthCheckPath: /health
            healthCheckInterval: 15s
    #服务实例ID
            instance-id: consul-tjw
    #应用名称
      application:
        name: consul-tjw
    #对外提供服务的端口
    server:
      port: 8502

3、添加服务启动代码，并对外提供服务

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 ConsumerApplication {
    	
    	@RequestMapping("/hi")
        public String home() {
            return "hi ,i'm tjw";
        }
    	
    	/*
    	 * 自检
    	 */
    	@RequestMapping("/health")
        public String health() {
            return "health";
        }
    	
    	public static void main(String[] args) {
    		SpringApplication.run(ConsumerApplication.class, args);
    	}
    }

4、启动服务提供者之后会在consul的管理页面中看到consul-tjw相关的服务信息

![70 2][]

#### Consul 服务消费者 ####

Consul的服务消费者不需要注册到consul（当然也可以注册到consul中），其只需要在使用服务时通过Consul对外提供的接口获取服务信息即可（应该与Eureka类似）

1、pom.xml中配置

<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">
    	<parent>
    	    <groupId>org.springframework.boot</groupId>
    	    <artifactId>spring-boot-starter-parent</artifactId>
    	    <version>1.5.10.RELEASE</version>
    	</parent>
    	
    	<dependencyManagement>
    	    <dependencies>
    	        <dependency>
    	            <groupId>org.springframework.cloud</groupId>
    	            <artifactId>spring-cloud-dependencies</artifactId>
    	            <version>Edgware.SR3</version>
    	            <type>pom</type>
    	            <scope>import</scope>
    	        </dependency>
    	    </dependencies>
    	</dependencyManagement>
    	<modelVersion>4.0.0</modelVersion>
    	<groupId>com.tianjunwei</groupId>
    	<artifactId>TJWspringCloud-consul-client</artifactId>
    	<version>1.0.0-SNAPSHOT</version>
    	<packaging>jar</packaging>
    	<name>TJWspringCloud-consul-client</name>
    	<dependencies>
    		<dependency>  
    	        <groupId>org.springframework.cloud</groupId>  
    	        <artifactId>spring-cloud-starter-consul-discovery</artifactId>  
    	    </dependency> 
    	    <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-core</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-classic</artifactId>  
            </dependency>  
            <dependency>  
                <groupId>ch.qos.logback</groupId>  
                <artifactId>logback-access</artifactId>  
            </dependency>  
    	</dependencies>
    	<build>
    		<resources>
    			<resource>
    				<directory>src/main/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/test/java</directory>
    				<includes>
    					<include>**/*.xml</include>
    				</includes>
    			</resource>
    			<resource>
    				<directory>src/main/resources</directory>
    				<includes>
    					<include>**/*.*</include>
    				</includes>
    			</resource>
    		</resources>
    		<plugins>  
    			<plugin>
    				<groupId>org.springframework.boot</groupId>
    				<artifactId>spring-boot-maven-plugin</artifactId>
    			</plugin>
    			
    	        <plugin>  
    	            <groupId>org.apache.maven.plugins</groupId>  
    	            <artifactId>maven-compiler-plugin</artifactId>  
    	            <version>2.0.2</version>  
    	            <configuration>  
    	                <source>1.8</source>  
    	                <target>1.8</target>  
    	            </configuration>  
    	        </plugin>  
    	    </plugins>  
    	</build>
    </project>

2、application.properties需要配置consul注册中心的地址，并且配置不需要注册到注册中心即可

server.port=8503
    spring.application.name=Consul-Client
    spring.cloud.consul.host=127.0.0.1
    spring.cloud.consul.port=8500
    #设置不需要注册到consul中
    spring.cloud.consul.discovery.register=false

3、服务消费者可以根据服务名远程调用服务提供者提供的接口

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.LoadBalanced;
    import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
    import org.springframework.context.annotation.Bean;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;  
      
    @SpringBootApplication  
    @EnableDiscoveryClient  
    @RestController  
    public class ConsulMainClient  {  
          
    	@Autowired
    	RestTemplate restTemplate;
    	
        @Autowired(required=true)    
        private LoadBalancerClient loadBalancer;  
          
        @Autowired(required=true)
        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-tjw").getUri().toString();  
        }  
          
        
    	@Bean
        @LoadBalanced
        public RestTemplate restTemplate() {
            return new RestTemplate();
        }
    
    	@RequestMapping(value = "/hi", method = RequestMethod.GET)
        public String add() {
            return restTemplate.getForEntity("http://consul-tjw/hi", String.class).getBody();
        }
        
        /** 
         * 获取所有服务  
         */  
        @RequestMapping("/services")  
        public Object services() {  
            return discoveryClient.getInstances("consul-tjw");  
        }  
          
        public static void main( String[] args ) {  
            SpringApplication.run(ConsulMainClient.class, args);  
        }  
    }

通过调用http://localhost:8503/hi即可获取到服务提供者提供的数据信息

![70 3][]

通过调用http://localhost:8503/services可以看到consul中提供的相关的服务的信息，存储的信息很简单类似Eureka注册中心

![70 4][]

[https_www.consul.io_downloads.html]: https://www.consul.io/downloads.html
[70]: /images/20220526/961fea85f7ff47749161699a646cb157.png
[70 1]: /images/20220526/721002615b7b487884963c3dea786ce5.png
[70 2]: /images/20220526/8dfe5d9404ce44dfa83185ca1cd98653.png
[70 3]: /images/20220526/4dc575e104c44b909aefc9aed00ea089.png
[70 4]: /images/20220526/697d9f476eab44c39082f5e15138c303.png