Wait for interface in main

main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"github.com/zettio/weavedns/server"
 	"log"
+	"net"
 	"os"
 )
 
@@ -36,7 +37,16 @@ func main() {
 		}
 	}
 
-	err := weavedns.StartServer(zone, ifaceName, dnsPort, httpPort, wait)
+	var iface *net.Interface = nil
+	if ifaceName != "" {
+		var err error
+		iface, err = weavedns.EnsureInterface(ifaceName, wait)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	err := weavedns.StartServer(zone, iface, dnsPort, httpPort, wait)
 	if err != nil {
 		log.Fatal("Failed to start server", err)
 	}

server/if_utils.go

@@ -7,7 +7,7 @@ import (
 	"time"
 )
 
-func ensureInterface(ifaceName string, wait int) (iface *net.Interface, err error) {
+func EnsureInterface(ifaceName string, wait int) (iface *net.Interface, err error) {
 	iface, err = findInterface(ifaceName)
 	if err == nil || wait == 0 {
 		return

server/server.go

@@ -69,24 +69,14 @@ func notUsHandler() dns.HandlerFunc {
 	}
 }
 
-func StartServer(zone Zone, ifaceName string, dnsPort int, httpPort int, wait int) error {
-
+func StartServer(zone Zone, iface *net.Interface, dnsPort int, httpPort int, wait int) error {
 	go ListenHttp(zone, httpPort)
 
-	var iface *net.Interface = nil
-	if ifaceName != "" {
-		var err error
-		iface, err = ensureInterface(ifaceName, wait)
-		if err != nil {
-			log.Fatal(err)
-		}
-	}
-
 	mdnsClient, err := NewMDNSClient()
 	if err != nil {
 		log.Fatal(err)
 	} else {
-		log.Printf("Using mDNS on %s", ifaceName)
+		log.Printf("Using mDNS on %s", iface.Name)
 	}
 	err = mdnsClient.Start(iface)
 	if err != nil {