add option to include local ip in qrcode

zapconnect.go

@@ -3,6 +3,7 @@ package main
 import (
 "flag"
 "fmt"
+"net"
 "io/ioutil"
 "github.com/Baozisoftware/qrcode-terminal-go"
 "encoding/json"
@@ -12,9 +13,29 @@ b64 "encoding/base64"
 type certificates struct {
 	Cert		string `json:"c"`
 	Macaroon	string `json:"m"`
+	Ip 			string `json:"ip,omitempty"`
+}
+
+func getLocalIP() string {
+	addrs, err := net.InterfaceAddrs()
+	if err != nil {
+		return ""
+	}
+	for _, address := range addrs {
+		if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				return ipnet.IP.String()
+			}
+		}
+	}
+	return ""
 }
 
 func main() {
+	ipPtr := flag.Bool("i", false, "Include local ip in QRCode.")
+	jsonPtr := flag.Bool("j", false, "Generate json instead of a QRCode.")
+	flag.Parse()
+
 	loadedConfig, _ := loadConfig()
 
 	certBytes, err := ioutil.ReadFile(loadedConfig.TLSCertPath)
@@ -29,17 +50,21 @@ func main() {
 
 	sEnc := b64.StdEncoding.EncodeToString([]byte(macBytes))
 
+	ipString := ""
+	if *ipPtr {
+		ipString = getLocalIP() + ":10009"
+	}
+
 	cert := &certificates{
 		Cert:	  string(certBytes),
-		Macaroon: sEnc}
+		Macaroon: sEnc,
+		Ip:		  ipString}
 	certB, _ := json.Marshal(cert)
 
-	jsonPtr := flag.Bool("j", false, "Generate json instead of a QRCode.")
-	flag.Parse()
 
-    if *jsonPtr {
-    	fmt.Print(string(certB))
-    } else {
+	if *jsonPtr {
+		fmt.Println(string(certB))
+	} else {
 		obj := qrcodeTerminal.New()
 		obj.Get(string(certB)).Print()
 	}