proxy/userspace: honor listen IP address as host IP if given

Allows the proxier to be used on an interface that's not the default route, otherwise hostIP gets set to the default route interface even if that's not what the user intended. If listen IP isn't given, falls back to previous behavior.

proxy/userspace: honor listen IP address as host IP if given
8a58f62f · Dan Williams · a9bf4410 · 8a58f62f
Commit 8a58f62f authored Jul 07, 2017 by Dan Williams
Hide whitespace changes
Inline Side-by-side

Showing with 9 additions and 3 deletions

proxier.go pkg/proxy/userspace/proxier.go +9 -3

No files found.
--- a/pkg/proxy/userspace/proxier.go
+++ b/pkg/proxy/userspace/proxier.go
@@ -166,9 +166,15 @@ func NewCustomProxier(loadBalancer LoadBalancer, listenIP net.IP, iptables iptab
 		return nil, ErrProxyOnLocalhost
 	}
-	hostIP, err := utilnet.ChooseHostInterface()
+	// If listenIP is given, assume that is the intended host IP.  Otherwise
-	if err != nil {
+	// try to find a suitable host IP address from network interfaces.
-		return nil, fmt.Errorf("failed to select a host interface: %v", err)
+	var err error
+	hostIP := listenIP
+	if hostIP.Equal(net.IPv4zero) {
+		hostIP, err = utilnet.ChooseHostInterface()
+		if err != nil {
+			return nil, fmt.Errorf("failed to select a host interface: %v", err)
+		}
 	}
 	err = setRLimit(64 * 1000)