Tiny Go proxy for dev use

proxy.go

package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
	"net/http/httputil"
	"net/url"
	"strings"
)

//Usage: go run proxy.go --port 8888 --host localhost:3010
func main() {
	portPtr := flag.Int("port", 3030, "local port to bind")
	hostPtr := flag.String("host", "", "host to proxy")

	flag.Parse()
	host := strings.TrimPrefix(*hostPtr, "http://")
	port := *portPtr

	if host == "" {
		log.Fatal("host is required")
	}

	proxy := httputil.NewSingleHostReverseProxy(&url.URL{
		Scheme: "http",
		Host:   host,
	})

	println(fmt.Sprintf("Proxying for %s on local port %v", host, port))
	err := http.ListenAndServe(fmt.Sprintf(":%d", port), proxy)
	if err != nil {
		println(err.Error())
	}
}