package main

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

func main() {
	listen := "0.0.0.0:8000"
	log.Print("Start simple server at port: ", listen)
	http.HandleFunc("/", handler)
	log.Fatal(http.ListenAndServe(listen, nil))
}

func handler(w http.ResponseWriter, r *http.Request) {

	log.Println("request from address: ", r.RemoteAddr)
	fmt.Fprintf(w, "%s %s %s\n", r.Method, r.URL, r.Proto)
	for k, v := range r.Header {
		fmt.Fprintf(w, "Header[%q] = %q\n", k, v)
	}
	fmt.Fprintf(w, "Host = %q\n", r.Host)
	fmt.Fprintf(w, "RemoteAddr = %q\n", r.RemoteAddr)
	if err := r.ParseForm(); err != nil {
		log.Print(err)
	}
	for k, v := range r.Form {
		fmt.Fprintf(w, "Form[%q] = %q\n", k, v)
	}
	fmt.Fprintf(w, "\n===> local IP: %q\n\n",GetOutboundIP())
	//fmt.Fprintf(w, "Env message = %s\n", os.Getenv("message"))
}

func GetOutboundIP() net.IP {
    conn, err := net.Dial("udp", "8.8.8.8:80")
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()

    localAddr := conn.LocalAddr().(*net.UDPAddr)

    return localAddr.IP
}