http-server.go

package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"net"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
)

//localIP 输出local ip
func localIP() []net.IP {
	ips := make([]net.IP, 0)
	if ifaces, err := net.Interfaces(); err == nil {
		// handle err
		for _, i := range ifaces {
			addrs, _ := i.Addrs()
			for _, addr := range addrs {
				var ip net.IP
				switch v := addr.(type) {
				case *net.IPNet:
					ip = v.IP
				case *net.IPAddr:
					ip = v.IP
				}

				if ip.To4() != nil {
					ips = append(ips, ip)
				}
			}
		}
	}

	return ips
}

//loggingHandler 输出log
func loggingHandler(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		//fmt.Println(*r.URL)
		start := time.Now()
		h.ServeHTTP(w, r)

		// log request by who(IP address)
		requesterIP := r.RemoteAddr
		ua := r.UserAgent()
		log.Printf(
			"%s\t%s\t%s\t%s\t%v",
			r.Method,
			r.RequestURI,
			requesterIP,
			ua,
			time.Since(start),
		)
	})
}

func main() {
	var port int
	flag.IntVar(&port, "p", 8080, "http 端口号  -p=8080")
	flag.Parse()

	sigs := make(chan os.Signal, 1)
	done := make(chan bool)
	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)

	_, cancel := context.WithCancel(context.Background())
	go func() {

		ips := ""
		for _, ip := range localIP() {
			ips = ips + fmt.Sprintf("        http://%s:%v\n", ip, port)
		}
		fmt.Println("Starting up http-server, serving ./")
		fmt.Println("Available on:")
		fmt.Printf("%s", ips)
		fmt.Println("Hit CTRL-C to stop the server")

		fs := http.FileServer(http.Dir("./"))
		http.Handle("/", loggingHandler(fs))

		//TODO 检测端口是否被暂用
		log.Println(http.ListenAndServe(fmt.Sprintf(":%v", port), nil))
	}()

	go func() {
		<-sigs
		cancel()
		done <- true
	}()

	<-done
	log.Println("http service stop.")
}