httpser.go

package main

import (
	"fmt"
	"log"
	"net/http"
)

/**
 * This is a production-ready, horizontally shardable, super fast HTTPS-redirector.
 *
 * It takes the URL and redirects you to HTTPS where you would run your real service.
 * This can work on a single port for any number of hosts so long as they aren't old browsers.
 */
func main() {
	log.Fatal(http.ListenAndServe(":80", http.HandlerFunc(handler)))
}

func handler(w http.ResponseWriter, req *http.Request) {
	host := req.Header.Get("Host")
	if host == "" {
		w.WriteHeader(http.StatusBadRequest)
		fmt.Fprintf(w, "Sorry, you did not send a Host header. Either you're a browser before 1996 or you're testing me with telnet. add https yourself.")
		return
	}
	target := "https://" + host + req.RequestURI
	w.Header.Set("Location", target)
	w.WriteHeader(http.StatusMovedPermanently)
	fmt.Fprintf(w, "Moved to %s", target)
}