Use ChooseHostInterface from kube to select interface

We need to select interface used to access default gateway, as docker0
bridge or Windows DockerNAT won't route traffic to containers by exposed
port

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

Author: ndeloof

Gopkg.lock

@@ -3,7 +3,6 @@ package e2e
 import (
 	"fmt"
 	"io/ioutil"
-	"net"
 	"strconv"
 	"strings"
 	"testing"
@@ -13,6 +12,7 @@ import (
 	"gotest.tools/assert"
 	"gotest.tools/fs"
 	"gotest.tools/icmd"
+	net2 "k8s.io/apimachinery/pkg/util/net"
 )
 
 // readFile returns the content of the file at the designated path normalizing
@@ -151,20 +151,16 @@ func (c *Container) getPort(t *testing.T) string {
 	return port
 }
 
+var host string
+
 func (c *Container) getIP(t *testing.T) string {
-	ip := "127.0.0.1"
-	// This won't work, but we can't guarantee computer has another IP
-	addrs, err := net.InterfaceAddrs()
-	assert.NilError(t, err)
-	for _, a := range addrs {
-		if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
-			if ipnet.IP.To4() != nil {
-				ip = ipnet.IP.String()
-				break
-			}
-		}
+	if host != "" {
+		return host
 	}
-	return ip
+	ip, err := net2.ChooseHostInterface()
+	assert.NilError(t, err)
+	host = ip.String()
+	return host
 }
 
 func (c *Container) Logs(t *testing.T) func() string {