我们想在基于Feign和Ribbon的微服务通信中使用HTTPS。这些服务是基于spring boot的，tomcat的设置是正确的。实例在Eureka上注册了HTTPS URL并启用了securePort。然而，当我们通过Feign调用另一个微服务时，底层的Ribbon无法识别该协议并退回到HTTP。我可以通过在FeignClient注解中添加协议来解决这个问题，就像这样。
@FeignClient("https://users")
但似乎Zuul代理和同样在内部使用Ribbon的Hystrix/Turbine也有同样的HTTP回退问题。有没有办法将Ribbon集中配置为默认使用HTTPS，或者使用注册的Eureka实例的securePort设置？
Eureka实例配置。
eureka.instance.hostname=localhost
eureka.instance.securePort = ${server.port}
eureka.instance.securePortEnabled = true
eureka.instance.nonSecurePortEnabled = false
eureka.instance.metadataMap.hostname = ${eureka.instance.hostname}
eureka.instance.metadataMap.securePort = ${server.port}
eureka.instance.homePageUrl = https://${eureka.instance.hostname}:${server.port}/
eureka.instance.statusPageUrl = https://${eureka.instance.hostname}:${server.port}/admin/info
通过这些设置，在Eureka中看起来服务是在HTTPS上运行的。Zuul代理运行良好，但使用HTTP URL来调用服务。你必须在Spring Boots嵌入式Tomcat中启用SSL，在keystore中提供一个服务器证书。
server.ssl.key-store=server.jks
server.ssl.key-store-password=<pw>
server.ssl.keyStoreType=jks
server.ssl.keyAlias=tomcat
server.ssl.key-password=<pw>
Tomcat只在HTTPS上运行，HTTP端口被屏蔽，但我得到的结果是：localhost:8081未能响应，因为使用了HTTP URL来调用服务。通过设置ribbon.IsSecure=true，正确地生成了用户服务的URL，但是Ribbon的负载平衡器却无法在Eureka中查找到用户服务。负载均衡器没有可用的服务器给客户端：用户。我还试着只在zuul代理中设置 users.ribbon.IsSecure=true，但仍然得到同样的错误。
Caused by: com.netflix.client.ClientException: Load balancer does not have available server for client: user
at com.netflix.loadbalancer.LoadBalancerContext.getServerFromLoadBalancer(LoadBalancerContext.java:468)
at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:184)
at com.netflix.loadbalancer.reactive.LoadBalancerCommand$1.call(LoadBalancerCommand.java:180)
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable.unsafeSubscribe(Observable.java:7304)
at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber$1.call(OperatorRetryWithPredicate.java:112)
at rx.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.enqueue(TrampolineScheduler.java:81)
at rx.schedulers.TrampolineScheduler$InnerCurrentThreadScheduler.schedule(TrampolineScheduler.java:59)
at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:77)
at rx.internal.operators.OperatorRetryWithPredicate$SourceSubscriber.onNext(OperatorRetryWithPredicate.java:45)
at rx.internal.util.ScalarSynchronousObservable$1.call(ScalarSynchronousObservable.java:41)
at rx.internal.util.ScalarSynchronousObservable$1.call(ScalarSynchronousObservable.java:30)
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable.subscribe(Observable.java:7393)
at rx.observables.BlockingObservable.blockForSingle(BlockingObservable.java:441)
at rx.observables.BlockingObservable.single(BlockingObservable.java:340)
at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:102)
at com.netflix.client.AbstractLoadBalancerAwareClient.executeWithLoadBalancer(AbstractLoadBalancerAwareClient.java:81)
at org.springframework.cloud.netflix.zuul.filters.route.RibbonCommand.forward(RibbonCommand.java:129)
at org.springframework.cloud.netflix.zuul.filters.route.RibbonCommand.run(RibbonCommand.java:103)
at org.springframework.cloud.netflix.zuul.filters.route.RibbonCommand.run(RibbonCommand.java:1)
at com.netflix.hystrix.HystrixCommand$1.call(HystrixCommand.java:298)
StackOverflow：Spring cloud: Ribbon and HTTPS - Stack Overflow