Google App Engine Static Website with Go Runtime

app.yaml

runtime: go
api_version: go1
threadsafe: yes

handlers:
- url: /.well-known/.*
  script: _go_app
- url: /.*
  script: _go_app
  secure: always
  redirect_http_response_code: 301

main.go

package main

import (
  "net/http"
)

func init() {
  http.Handle("/", http.FileServer(http.Dir("public")))
  http.HandleFunc("/.well-known/", LetsEncryptHandler)
}

func LetsEncryptHandler(w http.ResponseWriter, r *http.Request) {
  ctx := appengine.NewContext(r)
  
	key := strings.Split(r.URL.Path, "/")[3]
	  ctx.Infof("%s", key)
  
	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
  
	if item, err := memcache.Get(ctx, key); err == memcache.ErrCacheMiss {
		ctx.Infof("item not in the cache")
	} else if err != nil {
		ctx.Errorf("error getting item: %v", err)
	} else {
		ctx.Infof("the challenge is %q", item.Value)
		challenge := string(item.Value)
		w.Write([]byte(challenge))
	}
}