func MiddlewareFunc(h http.HandlerFunc, options ...nethttp.MWOption) http.HandlerFunc {
    next := func(w http.ResponseWriter, r *http.Request) {
        span := opentracing.SpanFromContext(r.Context())
        if span != nil {
            if sc, ok := span.Context().(jaeger.SpanContext); ok {
                w.Header().Set(traceIdHeader, sc.TraceID().String())
            }
        }

        h(w, r)
    }

    return nethttp.MiddlewareFunc(opentracing.GlobalTracer(), next, options...)
}