文章目录
【Spring Cloud Alibaba】Nacos 服务注册与发现
1、服务注册
首先创建一个名为：spring-cloud-alibaba-nacos-discovery 的引用，相关依赖为以下内容，核心依赖 spring-cloud-starter-alibaba-nacos-discovery
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
修改 application.properties 配置文件
server.port=8081
spring.application.name=spring-cloud-alibaba-nacos-discovery
management.server.port=9091
management.endpoints.jmx.exposure.include=*
management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always
# Nacos注册信息
spring.cloud.nacos.discovery.server-addr=192.168.31.141:8848
spring.cloud.nacos.discovery.username=nacos
spring.cloud.nacos.discovery.password=nacos
spring.cloud.nacos.discovery.namespace=sandbox-configuration
然后在启动类增加@EnableDiscoveryClient 注解
package cn.tellsea;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
/**
* nacos 服务注册与发现 - 提供者
*
* @author Tellsea
* @date 2021/12/20
*/
@SpringBootApplication
@EnableDiscoveryClient
public class SpringCloudAlibabaNacosDiscoveryApplication {
public static void main(String[] args) {
SpringApplication.run(SpringCloudAlibabaNacosDiscoveryApplication.class, args);
}
}
编写测试控制层
package cn.tellsea.controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
/**
* @author Tellsea
* @date 2021/12/20
*/
@RestController
public class ServiceController {
@GetMapping("/echo/{message}")
public String echo(@PathVariable String message) {
return "[ECHO] : " + message;
}
}
启动应用，查看日志，提示注册成功
2021-12-20 13:38:08.542 INFO 9420 --- [ main] c.a.c.n.registry.NacosServiceRegistry : nacos registry, DEFAULT_GROUP spring-cloud-alibaba-nacos-discovery 192.168.31.141:8081 register finished
查看 nacos 的服务注册
到此，服务注册完成
2、服务发现：@LoadBalanced + RestTemplate
创建一个新的应用名为 spring-cloud-alibaba-nacos-consumer
- 依赖和上一节的一样
- application.properties 和上一节的一样
- 启动类增加@EnableDiscoveryClient 注解和上一节的一样
编写测试控制器
package cn.tellsea.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
/**
* @author Tellsea
* @date 2021/12/20
*/
@RestController
public class RestTemplateController {
@LoadBalanced
@Autowired
public RestTemplate restTemplate;
@LoadBalanced
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
@GetMapping("/call/echo/{message}")
public String callEcho(@PathVariable String message) {
// 访问应用 spring-cloud-alibaba-nacos-discovery 的 REST "/echo/{message}"
return restTemplate.getForObject("http://spring-cloud-alibaba-nacos-discovery/echo/" + message, String.class);
}
}
启动应用，访问
http://localhost:8082/call/echo/66668888
发现浏览器返回
[ECHO] : 66668888
到这里，采用@LoadBalanced + RestTemplate 的方式实现了服务之间的调用
3、服务发现：Spring Cloud OpenFeign
首先消费者模式集成 Feign 依赖
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>2.2.2.RELEASE</version>
</dependency>
启动类上增加注解，表名激活 Feign
@EnableFeignClients
然后编写远程调用的 service 接口
package cn.tellsea.service;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
/**
* 指向服务提供者应用
*
* @author Tellsea
* @date 2021/12/20
*/
@FeignClient("spring-cloud-alibaba-nacos-discovery")
public interface EchoService {
/**
* 远程方法
*
* @param message
* @return
*/
@GetMapping("/echo/{message}")
String echo(@PathVariable("message") String message);
}
Feign 的控制层的方法直接注入之后调用即可
package cn.tellsea.controller;
import cn.tellsea.service.EchoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
/**
* Spring Cloud OpenFeign 远程调用
*
* @author Tellsea
* @date 2021/12/20
*/
@RestController
public class OpenFeignController {
@Autowired
private EchoService echoService;
@GetMapping("/feign/echo/{message}")
public String feignEcho(@PathVariable String message) {
return echoService.echo(message);
}
}
启动应用，访问
http://localhost:8082/feign/echo/66668888
发现浏览器返回
[ECHO] : 66668888
综上所述，Nacos Discovery 在 Spring Cloud 服务调用是无侵入的
4、断点监控
从上面的配置中不难看出，我们已经在配置文件中配置了端点监控的信息
management.server.port=9091
management.endpoints.jmx.exposure.include=*
management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always
Nacos Discovery 内部提供了一个 Endpoint, 对应的 endpoint id 为 nacosdiscovery，其 Actuator Web Endpoint URI 为/actuator/nacos-discovery
注：使用 Nacos Config Spring Cloud 1.x 版本的话，其 URI 地址则为/nacos-discovery ）
服务注册端点监控
http://127.0.0.1:9091/actuator/nacos-discovery
服务消费端点监控
http://127.0.0.1:9092/actuator/nacos-discovery