How to capture the host name of a request routed from Zuul?

[indrabasak]

I am using Dalston.SR3 for my Zuul server. The requests are routed using a Ribbon Client with Hystrix. Noticed that a server is allocated in LoadBalancerContext class for a given request. Is there a way to capture this host information? I am trying to keep track of in-flight requests per service ID and host.

[ryanjbaxter]

What do you want to do with the hostname?

[indrabasak]

We have the following requirements:

• keep track of in-flight requests per service ID and per host in Zuul.
• publish this information as metrics

It will ensure that no in-flight transactions are lost while a host is being rebooted.

[ryanjbaxter]

You might want to look into using a ZuulFilter to capture the information you need.

[indrabasak]

I have looked at ZuulFilter. I have a route and a post filter to keep track of the number of requests and responses per service ID respectively. However, I have no way of retrieving the host information since the HTTP client request takes places inside the RibbonRoutingFilter.

[ryanjbaxter]

Have you tried something like this? https://github.com/spring-cloud/spring-cloud-netflix/blob/master/spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/route/SimpleHostRoutingFilter.java#L232

[indrabasak]

@ryanjbaxter Thanks, I will take a look at it.