From 1a032a0cee93e7040dafd23fecce1c07e9d2331c Mon Sep 17 00:00:00 2001
From: Matt Miller <mamiller@rosettastone.com>
Date: Fri, 15 Dec 2017 11:12:45 -0500
Subject: [PATCH] add flag to set the host interface to use

---
 pkg/cmd/main.go              | 6 ++++--
 pkg/controller/keepalived.go | 1 +
 pkg/controller/main.go       | 9 ++++++---
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/pkg/cmd/main.go b/pkg/cmd/main.go
index c938d284..f753e352 100644
--- a/pkg/cmd/main.go
+++ b/pkg/cmd/main.go
@@ -76,6 +76,9 @@ var (
 		`The keepalived VRID (Virtual Router Identifier, between 0 and 255 as per 
       RFC-5798), which must be different for every Virtual Router (ie. every 
       keepalived sets) running on the same network.`)
+        
+        iface = flags.String("iface", "", `network interface to listen on. If undefined, the nodes
+                 default interface will be used instead`)
 )
 
 func main() {
@@ -118,14 +121,13 @@ func main() {
 	if *proxyMode {
 		copyHaproxyCfg()
 	}
-
 	kubeClient, err := createApiserverClient(*apiserverHost, *kubeConfigFile)
 	if err != nil {
 		handleFatalInitError(err)
 	}
 
 	glog.Info("starting LVS configuration")
-	ipvsc := controller.NewIPVSController(kubeClient, *watchNamespace, *useUnicast, *configMapName, *vrid, *proxyMode)
+	ipvsc := controller.NewIPVSController(kubeClient, *watchNamespace, *useUnicast, *configMapName, *vrid, *proxyMode, *iface)
 
 	ipvsc.Start()
 }
diff --git a/pkg/controller/keepalived.go b/pkg/controller/keepalived.go
index b12599ce..c415c7fe 100644
--- a/pkg/controller/keepalived.go
+++ b/pkg/controller/keepalived.go
@@ -81,6 +81,7 @@ func (k *keepalived) WriteCfg(svcs []vip) error {
 	conf["priority"] = k.priority
 	conf["useUnicast"] = k.useUnicast
 	conf["vrid"] = k.vrid
+        conf["iface"] = k.iface
 	conf["proxyMode"] = k.proxyMode
 	conf["vipIsEmpty"] = len(k.vips) == 0
 
diff --git a/pkg/controller/main.go b/pkg/controller/main.go
index 35360f0b..3f49985c 100644
--- a/pkg/controller/main.go
+++ b/pkg/controller/main.go
@@ -340,7 +340,7 @@ func (ipvsc *ipvsControllerController) Stop() error {
 }
 
 // NewIPVSController creates a new controller from the given config.
-func NewIPVSController(kubeClient *kubernetes.Clientset, namespace string, useUnicast bool, configMapName string, vrid int, proxyMode bool) *ipvsControllerController {
+func NewIPVSController(kubeClient *kubernetes.Clientset, namespace string, useUnicast bool, configMapName string, vrid int, proxyMode bool, iface string) *ipvsControllerController {
 	ipvsc := ipvsControllerController{
 		client:            kubeClient,
 		reloadRateLimiter: flowcontrol.NewTokenBucketRateLimiter(0.5, 1),
@@ -365,15 +365,18 @@ func NewIPVSController(kubeClient *kubernetes.Clientset, namespace string, useUn
 	if err != nil {
 		glog.Fatalf("Error getting local IP from nodes in the cluster: %v", err)
 	}
-
 	neighbors := getNodeNeighbors(nodeInfo, clusterNodes)
 
+        if iface == "" {
+          iface = nodeInfo.iface
+          glog.Info("No interface was provided, proceeding with the node's default: ", iface)
+        }
 	execer := utilexec.New()
 	dbus := utildbus.New()
 	iptInterface := utiliptables.New(execer, dbus, utiliptables.ProtocolIpv4)
 
 	ipvsc.keepalived = &keepalived{
-		iface:      nodeInfo.iface,
+		iface:      iface,
 		ip:         nodeInfo.ip,
 		netmask:    nodeInfo.netmask,
 		nodes:      clusterNodes,