Simple HTTP cache proxy

lestcache.go

package main

import (
	"crypto/md5"
	"flag"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"

	"github.com/bradfitz/gomemcache/memcache"
	"github.com/go-martini/martini"
)

func main() {
	serverURL := flag.String("server", "", "Server to be cached: --server htttp://foo.bar.com:1234/")
	memcacheURL := flag.String("memcache", "127.0.0.1:11211", "Memcache server: --memcache fake.memcache.server:11211")
	flag.Parse()

	if *serverURL == "" {
		flag.PrintDefaults()
		os.Exit(1)
	}

	m := martini.Classic()
	m.Map(memcache.New(*memcacheURL))

	m.Get("/**", func(res http.ResponseWriter, req *http.Request, cache *memcache.Client) {

		key := fmt.Sprintf("%x", md5.Sum([]byte(req.URL.String())))
		fmt.Println(key)

		item, err := cache.Get(key)

		if err != nil {
			fmt.Printf("Cache Error: %v\n", err)

			url := fmt.Sprintf("%s%s", *serverURL, req.URL)
			fmt.Printf("Calling %s\n", url)

			response, err := http.Get(url)
			defer response.Body.Close()

			if err != nil {
				res.WriteHeader(http.StatusInternalServerError)
				fmt.Fprint(res, err.Error())
				return
			}

			fmt.Printf("Storing in cache %s\n", req.URL)
			content, _ := ioutil.ReadAll(response.Body)
			item = &memcache.Item{Key: key, Value: content}

			if err := cache.Add(item); err != nil {
				fmt.Printf("Cache Error: %v\n", err)
			}
		} else {
			fmt.Printf("Got from cache %s\n", req.URL)
		}

		res.Header().Set("Content-Type", "application/json")
		res.WriteHeader(http.StatusOK)
		res.Write(item.Value)
	})
	m.Run()
}