Here a completely working example
package main
import (
// Standard library packages
"fmt"
"strconv"
"log"
"net"
"net/http"
// Third party packages
"github.com/julienschmidt/httprouter"
"github.com/skratchdot/open-golang/open"
)
// https://blog.golang.org/context/userip/userip.go
func getIP(w http.ResponseWriter, req *http.Request, _ httprouter.Params){
fmt.Fprintf(w, "<h1>static file server</h1><p><a href='./static'>folder</p></a>")
ip, port, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
//return nil, fmt.Errorf("userip: %q is not IP:port", req.RemoteAddr)
fmt.Fprintf(w, "userip: %q is not IP:port", req.RemoteAddr)
}
userIP := net.ParseIP(ip)
if userIP == nil {
//return nil, fmt.Errorf("userip: %q is not IP:port", req.RemoteAddr)
fmt.Fprintf(w, "userip: %q is not IP:port", req.RemoteAddr)
return
}
// This will only be defined when site is accessed via non-anonymous proxy
// and takes precedence over RemoteAddr
// Header.Get is case-insensitive
forward := req.Header.Get("X-Forwarded-For")
fmt.Fprintf(w, "<p>IP: %s</p>", ip)
fmt.Fprintf(w, "<p>Port: %s</p>", port)
fmt.Fprintf(w, "<p>Forwarded for: %s</p>", forward)
}
func main() {
myport := strconv.Itoa(10002);
// Instantiate a new router
r := httprouter.New()
r.GET("/ip", getIP)
// Add a handler on /test
r.GET("/test", func(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
// Simply write some test data for now
fmt.Fprint(w, "Welcome!\n")
})
l, err := net.Listen("tcp", "localhost:" + myport)
if err != nil {
log.Fatal(err)
}
// The browser can connect now because the listening socket is open.
//err = open.Start("http://localhost:"+ myport + "/test")
err = open.Start("http://localhost:"+ myport + "/ip")
if err != nil {
log.Println(err)
}
// Start the blocking server loop.
log.Fatal(http.Serve(l, r))
}