Example of creating a simple middleware function

createSimpleMiddleware.go

// logging is middleware for wrapping any handler we want to track response
// times for and to see what resources are requested.
func logging(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		req := fmt.Sprintf("%s %s", r.Method, r.URL)
		log.Println(req)
		next.ServeHTTP(w, r)
		log.Println(req, "completed in", time.Now().Sub(start))
	})
}