使用Springcloud Loadbalancer集成Openfeign报错

Question

使用Springcloud Loadbalancer集成Openfeign报错
报错内容

No qualifying bean of type 'org.springframework.cloud.client.discovery.ReactiveDiscoveryClient' available

application.yml配置文件

server:
  port: 8080
spring:
  application:
    name: consumer-01
  cloud:
    nacos:
      server-addr: localhost:8848
      discovery:
        namespace: c7ffbcd1-c4d8-425b-b41c-a1077693fa57
        group: A_GROUP
    loadbalancer:
      ribbon:
        enabled: false
      nacos:
        enabled: true
      enabled: true
      configurations: zone-preference
      zone: zone1
        hint:
        default: myhint

主类

@EnableDiscoveryClient
@EnableFeignClients
@SpringBootApplication
public class Consumer01Application {

    public static void main(String[] args) {
        SpringApplication.run(Consumer01Application.class, args);
    }
}

Openfeign controller（前端调用这个接口）

@RestController
public class OpenFeignController {

    @Autowired
    private FeignEchoService echoService;

    @GetMapping("/feign/echo/{message}")
    public String feignEcho(@PathVariable String message) {
        return echoService.echo(message);
    }
}

FeignEchoService配置，我的服务是provider-01，有三个实例

@LoadBalancerClient(name = "provider-01", configuration = CustomLoadBalancerConfig.class)
@FeignClient(value = "provider-01") // 指向服务提供者应用
public interface FeignEchoService {
    @LoadBalanced
    @GetMapping("/echo/{message}")
    String echo(@PathVariable("message") String message);
}

自定义的负载均衡配置，添加下面这个bean就会报错，不添加就正常运行，但是这样我没办法配置zone和hint

public class CustomLoadBalancerConfig {
    // 随机负载均衡
    @Bean
    ReactorLoadBalancer<ServiceInstance> randomLoadBalancer(Environment environment, LoadBalancerClientFactory loadBalancerClientFactory) {
        String name = environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
        return new RandomLoadBalancer(loadBalancerClientFactory.getLazyProvider(name, ServiceInstanceListSupplier.class), name);
    }

    // 配置zone
    @Bean
    public ServiceInstanceListSupplier discoveryClientServiceInstanceListSupplier(ConfigurableApplicationContext context) {
        return ServiceInstanceListSupplier.builder().withDiscoveryClient().withZonePreference().withCaching().build(context);
    }
}

provider-01的application.yml

server:
  port: 8081
spring:
  application:
    name: provider-01
  cloud:
    nacos:
      server-addr: localhost:8848
      discovery:
        namespace: c7ffbcd1-c4d8-425b-b41c-a1077693fa57
        group: A_GROUP
        metadata:
          zone: zone1
          hint: myhint
    loadbalancer:
      ribbon:
        enabled: false
      nacos:
        enabled: false
      enabled: true
      configurations: zone-preference

provider-01的controller

@RestController
public class EchoServiceController {

    @GetMapping("/echo/{message}")
    public String echo(@PathVariable String message) {
        return message;
    }
}

Answer 1

DiscoveryClient 和 ReactiveDiscoveryClient 代表服务消费者Consumer从注册中心发现服务提供者Provider的服务发现操作。两个接口的差异就体现在getServices()和getInstances(String serviceId)。只是把List类型转换成了Reactor里的Flux类型。Springcloud 默认使用的是DiscoveryClient ，在Spring WebFlux场景下，ReactiveDiscoveryClient才会生效，所以需要添加webflux依赖。

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>