Ignore previous serf user events to avoid wrong fdb programming

Signed-off-by: Santhosh Manohar <santhosh@docker.com>

libnetwork/drivers/overlay/ov_network.go

@@ -644,6 +644,9 @@ func (n *network) watchMiss(nlSock *nl.NetlinkSocket) {
 			}
 
 			if neigh.IP.To4() == nil {
+				if neigh.HardwareAddr != nil {
+					logrus.Debugf("Miss notification, l2 mac %v", neigh.HardwareAddr)
+				}
 				continue
 			}
 

libnetwork/drivers/overlay/ov_serf.go

@@ -73,7 +73,7 @@ func (d *driver) serfJoin(neighIP string) error {
 	if neighIP == "" {
 		return fmt.Errorf("no neighbor to join")
 	}
-	if _, err := d.serfInstance.Join([]string{neighIP}, false); err != nil {
+	if _, err := d.serfInstance.Join([]string{neighIP}, true); err != nil {
 		return fmt.Errorf("Failed to join the cluster at neigh IP %s: %v",
 			neighIP, err)
 	}
@@ -94,8 +94,8 @@ func (d *driver) notifyEvent(event ovNotify) {
 }
 
 func (d *driver) processEvent(u serf.UserEvent) {
-	logrus.Debugf("Received user event name:%s, payload:%s\n", u.Name,
-		string(u.Payload))
+	logrus.Debugf("Received user event name:%s, payload:%s LTime:%d \n", u.Name,
+		string(u.Payload), uint64(u.LTime))
 
 	var dummy, action, vtepStr, nid, eid, ipStr, maskStr, macStr string
 	if _, err := fmt.Sscan(u.Name, &dummy, &vtepStr, &nid, &eid); err != nil {
@@ -146,6 +146,7 @@ func (d *driver) processQuery(q *serf.Query) {
 		return
 	}
 
+	logrus.Debugf("Sending peer query resp mac %s, mask %s, vtep %s", peerMac, net.IP(peerIPMask), vtep)
 	q.Respond([]byte(fmt.Sprintf("%s %s %s", peerMac.String(), net.IP(peerIPMask).String(), vtep.String())))
 }
 
@@ -173,6 +174,7 @@ func (d *driver) resolvePeer(nid string, peerIP net.IP) (net.HardwareAddr, net.I
 			return nil, nil, nil, fmt.Errorf("failed to parse mac: %v", err)
 		}
 
+		logrus.Debugf("Received peer query response, mac %s, vtep %s, mask %s", macStr, vtepStr, maskStr)
 		return mac, net.IPMask(net.ParseIP(maskStr).To4()), net.ParseIP(vtepStr), nil
 
 	case <-time.After(time.Second):

libnetwork/osl/neigh_linux.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net"
 
+	"github.com/Sirupsen/logrus"
 	"github.com/vishvananda/netlink"
 )
 
@@ -96,6 +97,7 @@ func (n *networkNamespace) AddNeighbor(dstIP net.IP, dstMac net.HardwareAddr, op
 
 	nh := n.findNeighbor(dstIP, dstMac)
 	if nh != nil {
+		logrus.Debugf("Neighbor entry already present for IP %v, mac %v", dstIP, dstMac)
 		// If it exists silently return
 		return nil
 	}