Example of caching and gzip, httprouter

gzip.go

package gzip

import (
	"compress/gzip"
	"io"
	"net/http"
	"strings"

	"github.com/julienschmidt/httprouter"
)

// GzipResponseWriter is a Struct for manipulating io writer
type GzipResponseWriter struct {
	io.Writer
	http.ResponseWriter
}

func (res GzipResponseWriter) Write(b []byte) (int, error) {
	if "" == res.Header().Get("Content-Type") {
		// If no content type, apply sniffing algorithm to un-gzipped body.
		res.Header().Set("Content-Type", http.DetectContentType(b))
	}
	return res.Writer.Write(b)
}

// Middleware force - bool, whether or not to force Gzip regardless of the sent headers.
func Middleware(fn httprouter.Handle, force bool) httprouter.Handle {
	return func(res http.ResponseWriter, req *http.Request, pm httprouter.Params) {
		if !strings.Contains(req.Header.Get("Accept-Encoding"), "gzip") && !force {
			fn(res, req, pm)
			return
		}
		res.Header().Set("Vary", "Accept-Encoding")
		res.Header().Set("Content-Encoding", "gzip")
		gz := gzip.NewWriter(res)
		defer gz.Close()
		gzr := GzipResponseWriter{Writer: gz, ResponseWriter: res}
		fn(gzr, req, pm)
	}
}

router.go

func GetRoutes() *httprouter.Router {
	router := httprouter.New()
	///////////////////////////////////////////////////////////
	// Main application routes
	///////////////////////////////////////////////////////////

	application := controllers.Application{}
	router.GET("/", gzip.Middleware(application.Index, false))
  
	///////////////////////////////////////////////////////////
	// Static routes
	// Caching Static files
	///////////////////////////////////////////////////////////
	fileServer := http.FileServer(http.Dir("public"))
	router.GET("/static/*filepath", func(res http.ResponseWriter, req *http.Request, pm httprouter.Params) {
		res.Header().Set("Vary", "Accept-Encoding")
		res.Header().Set("Cache-Control", "public, max-age=7776000")
		req.URL.Path = pm.ByName("filepath")
		fileServer.ServeHTTP(res, req)
	})
	return router
}