简单教程: Spring Cloud Consul Ribbon/Feign超详细教程【1024程序员节日快乐】

1. 安装consul

自行搜索

快速启动的方法:

./consul agent -dev -client=0.0.0.0

--client 用0.0.0.0表示不限客户端(调用方)的IP

注意: OS X 用户：Consul 使用 hostname 做 node name，如果 node name 包含句点，会导致 DNS 无法工作，所以需要显式设置 node name 用 -node flag

./consul agent -dev -client=0.0.0.0 -node=node0

我的开发地址是:192.168.6.244, 访问http://192.168.6.244:8500可以看到界面:

2.创建Spring-Cloud服务,注册到上面的地址

pom.xml 主要内容（spring-boot-starter-web/test自己添加）:

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

main.class

@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ConsulCloudApplication {

	public static void main(String[] args) {
		SpringApplication.run(ConsulCloudApplication.class, args);
	}
    @GetMapping(value = "/hello")
    public String hello() {
        return "My First Consul.";
    }

}

application.yml:

spring:
  application:
    name: consul-cloud-1
  cloud:
    consul:
      host: 192.168.6.244
      port: 8500
      discovery:
        service-name: my-first-consul-service # 服务调用的名字
        health-check-interval: 15s
server:
  port: 8501

同时复制一份副本,修改端口为8502,application name 为consul-cloud-2, hello()方法返回为"My Fitst Consul 2"

启动这两个应用之后，再访问http://192.168.6.244:8500

你会看到:

 

这说明已经注册成功

3.开启spring-cloud-comsumer来消费服务

pom.xml主要内容

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

目录结构:

application.yml:

spring:
  application:
    name: consul-cloud-consumer
  cloud:
    consul:
      host: 192.168.6.244
      port: 8500
      discovery:
        register: false # 仅作为消费者, 不注册服务
server:
  port: 8503

 

ConsulCloudConsumerApplication.class:

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class ConsulCloudConsumerApplication {

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

    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate();
    }

}

com.springcloud.controller下的Consumer:

@RestController
public class Consumer {

    private Logger log = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private LoadBalancerClient loadBalancerClient;


    @Autowired
    private DiscoveryClient discoveryClient;

    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private FeignService feignService;

    @GetMapping(value = "/getServices")
    public Object getServices() {
        return discoveryClient.getInstances("my-first-consul-service");
    }

    // 轮询的选择同服务(来自不同的客户注册中心,IP不同)
    @GetMapping(value = "/chooseService")
    public Object chooseService() {
        return loadBalancerClient.choose("my-first-consul-service").getUri().toString();
    }

    // -------------------------- ribbon --------------------------
    @GetMapping(value = "/ribbon-call")
    public String ribbonCall() {
        String method = "hello";
        return restTemplate.getForEntity("http://my-first-consul-service/" + method, String.class).getBody();
    }

    // -------------------------- Feign --------------------------
    @GetMapping(value = "/feign-call")
    public String feignCall() {
        return feignService.hello();
    }

}

com.springcloud.service.FeignService下的FeignService

@FeignClient("my-first-consul-service")
@Component
public interface FeignService {
    @RequestMapping(value = "/hello")
    public String hello(); // 如果有参数, 必须用RequestParam注解

}

启动消费者项目,分别访问:

http://localhost:8503/getServices

可以看到:

[
    {
        "serviceId": "my-first-consul-service",
        "host": "192.168.101.137",
        "port": 8501,
        "secure": false,
        "metadata": {
            "secure": "false"
        },
        "uri": "http://192.168.101.137:8501",
        "scheme": null
    },
    {
        "serviceId": "my-first-consul-service",
        "host": "192.168.101.137",
        "port": 8502,
        "secure": false,
        "metadata": {
            "secure": "false"
        },
        "uri": "http://192.168.101.137:8502",
        "scheme": null
    }
]

访问:http://localhost:8503/ribbon-call和http://localhost:8503/feign-call

轮回出现:

My First Consul.

My First Consul. 2

 

参考资料 :

http://www.ityouknow.com/springcloud/2018/07/20/spring-cloud-consul.html

https://www.consul.io/