解密Spring Cloud微服务调用：如何轻松获取请求目标方的IP和端口 - ToB企服应用市场:ToB评测及商务社交产业平台

/**
* 因为调用目标机器的时候，如果目标机器本身假死或者调用目标不通无法数据返回，那么feign无法打印目标机器。这种场景下我们需要在调用失败（目标机器没有返回）的时候也能把目标机器的ip打印出来，这种场景需要我们切入feign选择机器的逻辑，注入我们自己的调度策略（默认是roundrobin），在里面打印选择的机器即可。
*/
@Slf4j
public class FeignRule extends RoundRobinRule {
@Override
public Server choose(Object key) {
Server server = super.choose(key);
if (Objects.isNull(server)) {
log.info("server is null");
return null;
}
log.info("feign rule ---> serverName:{}, choose key:{}, final server ip:{}", server.getMetaInfo().getAppName(), key, server.getHostPort());
return server;
}
@Override
public Server choose(ILoadBalancer lb, Object key) {
Server chooseServer = super.choose(lb, key);
List<Server> reachableServers = lb.getReachableServers();
List<Server> allServers = lb.getAllServers();
int upCount = reachableServers.size();
int serverCount = allServers.size();
log.info("serverName:{} upCount:{}, serverCount:{}", Objects.nonNull(chooseServer) ? chooseServer.getMetaInfo().getAppName() : "", upCount, serverCount);
for (Server server : allServers) {
if (server instanceof DiscoveryEnabledServer) {
DiscoveryEnabledServer dServer = (DiscoveryEnabledServer) server;
InstanceInfo instanceInfo = dServer.getInstanceInfo();
if (instanceInfo != null) {
InstanceInfo.InstanceStatus status = instanceInfo.getStatus();
if (status != null) {
log.info("serverName:{} server:{}, status:{}", server.getMetaInfo().getAppName(), server.getHostPort(), status);
}
}
}
}
return chooseServer;
}
}

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import org.springframework.cloud.netflix.ribbon.RibbonClients;
import org.springframework.context.annotation.Configuration;
/**
* @description:feign 配置
*/
@Configuration
@RibbonClients(defaultConfiguration = {FeignRule.class})
public class FeignConfig {
}

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@Slf4j
public class CustomRoundRobinLoadBalancer implements ReactorServiceInstanceLoadBalancer {
final AtomicInteger position;
final String serviceId;
ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider;
public CustomRoundRobinLoadBalancer(ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider, String serviceId) {
this(serviceInstanceListSupplierProvider, serviceId, (new Random()).nextInt(1000));
}
public CustomRoundRobinLoadBalancer(ObjectProvider<ServiceInstanceListSupplier> serviceInstanceListSupplierProvider, String serviceId, int seedPosition) {
this.serviceId = serviceId;
this.serviceInstanceListSupplierProvider = serviceInstanceListSupplierProvider;
this.position = new AtomicInteger(seedPosition);
}
public Mono<Response<ServiceInstance>> choose(Request request) {
ServiceInstanceListSupplier supplier = this.serviceInstanceListSupplierProvider.getIfAvailable(NoopServiceInstanceListSupplier::new);
return supplier.get(request).next().map((serviceInstances) -> {
return this.processInstanceResponse(supplier, serviceInstances);
});
}
private Response<ServiceInstance> processInstanceResponse(ServiceInstanceListSupplier supplier, List<ServiceInstance> serviceInstances) {
Response<ServiceInstance> serviceInstanceResponse = this.getInstanceResponse(serviceInstances);
if (supplier instanceof SelectedInstanceCallback && serviceInstanceResponse.hasServer()) {
((SelectedInstanceCallback)supplier).selectedServiceInstance((ServiceInstance)serviceInstanceResponse.getServer());
}
return serviceInstanceResponse;
}
private Response<ServiceInstance> getInstanceResponse(List<ServiceInstance> instances) {
if (instances.isEmpty()) {
if (log.isWarnEnabled()) {
log.warn("No servers available for service: " + this.serviceId);
}
return new EmptyResponse();
} else {
int pos = this.position.incrementAndGet() & Integer.MAX_VALUE;
ServiceInstance instance = instances.get(pos % instances.size());
log.info("serverName:{} upCount:{}",instance.getServiceId(),instances.size());
log.info("feign rule ---> serverName:{}, final server ip:{}:{}", instance.getServiceId(), instance.getHost(),instance.getPort());
return new DefaultResponse(instance);
}
}
}

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@Configuration
@LoadBalancerClients(defaultConfiguration = CustomLoadBalancerConfiguration.class)
public class CustomLoadBalancerConfig {
}
@Configuration
class CustomLoadBalancerConfiguration {
/**
* 参考默认实现
* @see org.springframework.cloud.loadbalancer.annotation.LoadBalancerClientConfiguration#reactorServiceInstanceLoadBalancer
* @return
*/
@Bean
public ReactorLoadBalancer<ServiceInstance> reactorServiceInstanceLoadBalancer(Environment environment, LoadBalancerClientFactory loadBalancerClientFactory) {
String name = environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
return new CustomRoundRobinLoadBalancer(loadBalancerClientFactory.getLazyProvider(name, ServiceInstanceListSupplier.class), name);
}
}

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