Non-httprouter routers and how to write a response time tracker middleware for them

README.md

See the section in each example labelled as MAGIC for how to get the route pattern which matched the url path for each router.

goji.go

package main

import (
	"log"
	"net/http"
	"time"

	goji "goji.io"
	"goji.io/middleware"
	"goji.io/pat"
	"golang.org/x/net/context"
)

func main() {

	m := goji.NewMux()
	m.HandleFuncC(pat.Get("/ordereditems/:key"), fake)
	m.HandleFuncC(pat.Post("/ordereditems/:key"), fake)
	m.HandleFuncC(pat.Get("/ordereditems/:key/items"), fake)
	m.HandleFuncC(pat.Post("/ordereditems/:key/items"), fake)
	m.HandleFuncC(pat.Put("/ordereditems/:key/items/:itemID/position"), fake)

	m.UseC(tracker)
	log.Println(http.ListenAndServe(":2380", m))
}

func tracker(next goji.Handler) goji.Handler {
	service := "myService"
	f := func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		next.ServeHTTPC(ctx, w, r)
		
		// THIS IS THE MAGIC
		p := middleware.Pattern(ctx)
		// END MAGIC
		
		log.Printf("track service %s path %s time %s", service, p, time.Since(start))
	}
	return goji.HandlerFunc(f)
}

func fake(ctx context.Context, w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusNoContent)
}

gorilla.go

package main

import (
	"log"
	"net/http"
	"time"

	"github.com/gorilla/mux"
)

func main() {

	m := mux.NewRouter()
	m.KeepContext = true // necessary for mux.CurrentRoute to work in middleware
	s := m.PathPrefix("/ordereditems").Subrouter()
	s.HandleFunc("/{key}", fake).Methods("GET")
	s.HandleFunc("/{key}", fake).Methods("POST")
	s.HandleFunc("/{key}/items", fake).Methods("POST", "GET")
	s.HandleFunc("/{key}/items/{itemID}/position", fake).Methods("PUT")

	log.Println(http.ListenAndServe(":2380", tracker(m)))
}

func tracker(next http.Handler) http.Handler {
	service := "myService"
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		start := time.Now()
		next.ServeHTTP(w, r)
		
		// THIS IS THE MAGIC
		route := mux.CurrentRoute(r)
		if route == nil {
			return
		}

		p, err := route.GetPathTemplate()
		if err != nil {
			p = "unknown_path"
		}
		// END MAGIC
		
		log.Printf("track service %s path %s time %s", service, p, time.Since(start))
	})
}

func fake(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusNoContent)
}