Run Go Web Server

// StartServer serves Handler over HTTPS(443) with a redirect on 80
// using an ACME certificate it creates & is cached in ./certs/
// and has sensible timeouts to avoid nasty clients.
// Note the timeouts don't work for slow transfers, 
// but oddly are ok for websockets.
func StartServer(engine http.Handler, ...hostname string)
  certManager := autocert.Manager{
    Prompt:     autocert.AcceptTOS,
    HostPolicy: autocert.HostWhitelist(hostname...),
    Cache:      autocert.DirCache("certs"),
  }

  s := &http.Server{
    Addr:              ":https",
    Handler:           engine,
    TLSConfig:         certManager.TLSConfig(),
    WriteTimeout:      10 * time.Second,
    IdleTimeout:       120 * time.Second,
    ReadHeaderTimeout: 2 * time.Second,
  }
  go http.ListenAndServe(":80", certManager.HTTPHandler(nil))
  log.Fatal(s.ListenAndServeTLS("", ""))
}