myip/cmd/client.go

package cmd

import (
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"net/http"
	"os"
	"sort"
	"strings"
	"text/tabwriter"
	"time"

	"github.com/robfig/cron/v3"
	"github.com/spf13/cobra"
)

var (
	port string
	host string
	name string

	showTitle bool
	showList  bool
	showAll   bool
	showCell  bool

	noPub  bool
	secure bool

	cronMode bool
	cronSpec string
)

type Iface struct {
	IP           string
	HardwareAddr string
	Name         string
}

var ClientCmd = &cobra.Command{
	Use:   "myip",
	Short: "myip is a easy way to get public ip of current system.",
	Run: func(cmd *cobra.Command, args []string) {
		if name == "" {
			name, _ = os.Hostname()
		}
		if cronMode {
			block := make(chan struct{}, 1)
			c := cron.New()
			c.AddFunc(cronSpec, func() {
				Scan()
				fmt.Println()
			})
			c.Start()
			<-block
		} else {
			Scan()
		}
	},
}

func init() {
	ClientCmd.Flags().StringVarP(&port, "port", "p", "5080", "server port to connect")
	ClientCmd.Flags().StringVarP(&host, "host", "u", "kumoly.io", "hostname to connect")
	ClientCmd.Flags().StringVarP(&name, "name", "n", "", "tell the server who you are")

	ClientCmd.Flags().BoolVarP(&showList, "list", "l", false, "show list")
	ClientCmd.Flags().BoolVarP(&showTitle, "title", "t", false, "show title, used with --list")
	ClientCmd.Flags().BoolVarP(&showCell, "cell", "c", false, "show cell, must used with --list")
	ClientCmd.Flags().BoolVarP(&showAll, "all", "a", false, "show local ip")

	ClientCmd.Flags().BoolVar(&noPub, "no-pub", false, "disable PublicIP")
	ClientCmd.Flags().BoolVar(&secure, "secure", false, "use https")

	ClientCmd.Flags().BoolVar(&cronMode, "cron", false, "run as cron service")
	ClientCmd.Flags().StringVarP(&cronSpec, "spec", "s", "0 */5 * * * *", "hostname to connect")
}

func Scan() error {
	// fmt.Printf("title: %v\nlist: %v\nall: %v\ntab: %v\n", showTitle, showList, showAll, showCell)
	if !showAll {
		if noPub {
			return errors.New("`--no-pub` can only be used with `--all`")
		}
		ip, err := GetPublicIP()
		if err != nil {
			return err
		}
		fmt.Println(ip)
	} else {
		var ip string
		var err error
		if !noPub {
			ip, err = GetPublicIP()
			if err != nil {
				return err
			}
		}
		local, err := GetLocalIP()
		if err != nil {
			return err
		}
		if showList {
			var wFlag uint = 0
			if showCell {
				wFlag = tabwriter.Debug
			}
			w := tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', wFlag)
			if showTitle {
				fmt.Fprintln(w, "\tInterface\tIP\t")
				if showCell {
					fmt.Fprintln(w, "\t\t\t")
				}
			}
			if !noPub {
				fmt.Fprintf(w, "\t%v\t%v\t\n", "PublicIP", ip)
			}
			for _, iface := range local {
				fmt.Fprintf(w, "\t%v\t%v\t\n", iface.Name, iface.IP)
			}
			return w.Flush()

		} else {
			if !noPub {
				fmt.Printf("%v ", ip)
			}
			for _, v := range local {
				fmt.Printf("%v ", v.IP)
			}
			fmt.Printf("\n")
		}
	}
	return nil
}

func GetLocalIP() ([]Iface, error) {
	ret := []Iface{}
	ifaces, err := net.Interfaces()
	if err != nil {
		log.Println(err)
		return ret, err
	}

	for _, i := range ifaces {
		addrs, err := i.Addrs()
		if err != nil {
			log.Println(err)
			return ret, err
		}

		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
				if ip.IsLoopback() {
					continue
				}
				if ip.To4() == nil {
					continue
				}
			case *net.IPAddr:
				continue
				// ip = v.IP
				// if ip.IsLoopback() {
				// 	continue
				// }
			}
			ret = append(ret, Iface{
				IP:           ip.String(),
				Name:         i.Name,
				HardwareAddr: i.HardwareAddr.String(),
			})
			break
		}
	}
	sort.Slice(ret, func(i, j int) bool {
		return ret[i].Name < ret[j].Name
	})
	return ret, nil
}

func GetPublicIP() (string, error) {
	protocol := "http://"
	if secure {
		protocol = "https://"
	}
	req, _ := http.NewRequest("GET", protocol+host+":"+port+"?name="+name, nil)
	client := &http.Client{
		Timeout: time.Second * 10,
	}
	res, err := client.Do(req)
	if err != nil {
		log.Println(err)
		return "", err
	}
	if res.StatusCode != 200 {
		err = errors.New("http status error: " + res.Status)
		log.Println(err)
		return "", err
	}
	defer res.Body.Close()
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		log.Println(err)
		return "", err
	}
	return strings.TrimRight(string(body), "\r\n"), nil
}