App Engine Go 1.11 memcache proof

app.yaml

runtime: go111

main.go

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"time"

  "github.com/gorilla/mux"
	"google.golang.org/appengine"
	"google.golang.org/appengine/log"
	"google.golang.org/appengine/memcache"
)

func main() {
	r := mux.NewRouter()

	// Frontend pages.
	r.HandleFunc("/", indexHandler)

	http.Handle("/", r)

	appengine.Main()
}

func indexHandler(w http.ResponseWriter, r *http.Request) {
	ctx := appengine.NewContext(r)

	data := map[string]string{
		"alpha": "beta",
	}

	myCodec := memcache.Codec{json.Marshal, json.Unmarshal}

	retData := map[string]string{}
	if _, err := myCodec.Get(ctx, "go111-test", &retData); err == nil {
		http.Error(w, fmt.Sprintf("From Cache: %#v", retData), 200)
		return
	} else {
		cacheItem := &memcache.Item{
			Key:        "go111-test",
			Object:     data,
			Expiration: time.Hour,
		}
		if err := myCodec.Set(ctx, cacheItem); err != nil {
			log.Errorf(ctx, "GetSettingsValue: Cache Save Error (%s): %s", "go111-test", err)
		}
		http.Error(w, fmt.Sprintf("Set Cache: %#v", data), 200)
		return
	}
	http.Error(w, "Permission Denied", 403)
}