Simple groupcache example

groupcache.go

// Simple groupcache example: https://github.com/golang/groupcache
// Running 3 instances:
// go run groupcache.go -addr=:8080 -pool=http://127.0.0.1:8080,http://127.0.0.1:8081,http://127.0.0.1:8082
// go run groupcache.go -addr=:8081 -pool=http://127.0.0.1:8081,http://127.0.0.1:8080,http://127.0.0.1:8082
// go run groupcache.go -addr=:8082 -pool=http://127.0.0.1:8082,http://127.0.0.1:8080,http://127.0.0.1:8081
// Testing:
// curl localhost:8080/color?name=red
package main

import (
	"errors"
	"flag"
	"log"
	"net/http"
	"strings"

	"github.com/golang/groupcache"
)

var Store = map[string][]byte{
	"red":   []byte("#FF0000"),
	"green": []byte("#00FF00"),
	"blue":  []byte("#0000FF"),
}

var Group = groupcache.NewGroup("foobar", 64<<20, groupcache.GetterFunc(
	func(ctx groupcache.Context, key string, dest groupcache.Sink) error {
		log.Println("looking up", key)
		v, ok := Store[key]
		if !ok {
			return errors.New("color not found")
		}
		dest.SetBytes(v)
		return nil
	},
))

func main() {
	addr := flag.String("addr", ":8080", "server address")
	peers := flag.String("pool", "http://localhost:8080", "server pool list")
	flag.Parse()
	http.HandleFunc("/color", func(w http.ResponseWriter, r *http.Request) {
		color := r.FormValue("name")
		var b []byte
		err := Group.Get(nil, color, groupcache.AllocatingByteSliceSink(&b))
		if err != nil {
			http.Error(w, err.Error(), http.StatusNotFound)
			return
		}
		w.Write(b)
		w.Write([]byte{'\n'})
	})
	p := strings.Split(*peers, ",")
	pool := groupcache.NewHTTPPool(p[0])
	pool.Set(p...)
	http.ListenAndServe(*addr, nil)
}

HI.. I am unable to get the github.com/golang/groupcache.
How to get ?

You probably need to update to accommodate golang/groupcache#131. make use of the standard library's context.Context.

line 45 should pass context.TODO() instead of nil, or it will panic on modern compilers.

Can we fetch the current set of peers in the pool if we are setting up peers dynamically