Distributed tracing with golang http.PostForm

Question

In my project, I try to implement distributed tracing using opentracing.

My microservice has following structure.

-- API-Gateway
       |_ User-Service
       |_ Notification 

In my API-gateway, I start and in API gateway, I use a to a function to start tracing, code is taken from Setting up your tracer

in main():

gatewayTracer := &apiTracer{tracer: startTracing("API Gateway")}

http.HandleFunc("/getemail", gatewayTracer.validatemail)

func (apitracer apiTracer) validatemail(res http.ResponseWriter, req *http.Request) {

    validateEmailSpan := apitracer.tracer.StartSpan("Validate Email")
}

I call to my User-service from validateemail() using http.PostForm().

_, err := http.PostForm("http://user:7071/checkemail", url.Values{"uuid": {uuid}, "email": {email}})

Here uuid is for separate task, not for tracing. I can not post this Span to the next service using PostForm().

How to overcome this issue?

Answer 1

I don't think it can be done from PostForm. You would need to use http.NewRequest to create the POST request, Inject the span in headers and use Client.Do to send the request.