What tags are available in RestTemplate-instrumented spans using Spring Cloud Sleuth

Question

I'm including Spring Cloud Sleuth + Zipkin 2.2.7 in my Spring Boot application, and am using injected RestTemplates so that calls to them are instrumented and sent to zipkin.

My zipkin spans arising from RestTemplate calls contain tags for http.method and http.path, but no other HTTP info.

Is there any way to surface query parameters in tags? Sometimes there is interesting information in them that would be really useful to surface in a tag (e.g. GET /foo?includeSuperSensitiveData=true).

Answer 1

Let me try to explain what is going on under the hood:

TraceRestTemplateBeanPostProcessor modifies all the RestTemplate beans. As you can see there, it injects a LazyTracingClientHttpRequestInterceptor that is using a brave.spring.web.TracingClientHttpRequestInterceptor to instrument the http calls. So this is done by Brave, not Sleuth.

You might be able to extend TracingClientHttpRequestInterceptor, add the details you need to your implementation and create a bean (you might need to disable the config class that creates it if there is no @ConditionalOnMissingBean).