From f5f576ad349e345b4479fce15a9c0a46718b604f Mon Sep 17 00:00:00 2001
From: Jana Radhakrishnan <mrjana@docker.com>
Date: Tue, 14 Jun 2016 12:39:38 -0700
Subject: [PATCH] Properly purge node networks when node goes away

When a node goes away purge all the network attachments from the node
and make sure we don't attempt bulk syncing to that node once removed.

Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
---
 libnetwork/networkdb/cluster.go        | 17 +++++++++++------
 libnetwork/networkdb/event_delegate.go |  1 +
 libnetwork/networkdb/networkdb.go      | 20 +++++++++++++++++++-
 3 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/libnetwork/networkdb/cluster.go b/libnetwork/networkdb/cluster.go
index 7b1384510c..e11aae9e2f 100644
--- a/libnetwork/networkdb/cluster.go
+++ b/libnetwork/networkdb/cluster.go
@@ -311,7 +311,16 @@ func (nDB *NetworkDB) bulkSyncTables() {
 		nid := networks[0]
 		networks = networks[1:]
 
-		completed, err := nDB.bulkSync(nid, false)
+		nDB.RLock()
+		nodes := nDB.networkNodes[nid]
+		nDB.RUnlock()
+
+		// No peer nodes on this network. Move on.
+		if len(nodes) == 0 {
+			continue
+		}
+
+		completed, err := nDB.bulkSync(nid, nodes, false)
 		if err != nil {
 			logrus.Errorf("periodic bulk sync failure for network %s: %v", nid, err)
 			continue
@@ -334,11 +343,7 @@ func (nDB *NetworkDB) bulkSyncTables() {
 	}
 }
 
-func (nDB *NetworkDB) bulkSync(nid string, all bool) ([]string, error) {
-	nDB.RLock()
-	nodes := nDB.networkNodes[nid]
-	nDB.RUnlock()
-
+func (nDB *NetworkDB) bulkSync(nid string, nodes []string, all bool) ([]string, error) {
 	if !all {
 		// If not all, then just pick one.
 		nodes = nDB.mRandomNodes(1, nodes)
diff --git a/libnetwork/networkdb/event_delegate.go b/libnetwork/networkdb/event_delegate.go
index 4a924482e7..7dfea84f6e 100644
--- a/libnetwork/networkdb/event_delegate.go
+++ b/libnetwork/networkdb/event_delegate.go
@@ -14,6 +14,7 @@ func (e *eventDelegate) NotifyJoin(n *memberlist.Node) {
 
 func (e *eventDelegate) NotifyLeave(n *memberlist.Node) {
 	e.nDB.deleteNodeTableEntries(n.Name)
+	e.nDB.deleteNetworkNodeEntries(n.Name)
 	e.nDB.Lock()
 	delete(e.nDB.nodes, n.Name)
 	e.nDB.Unlock()
diff --git a/libnetwork/networkdb/networkdb.go b/libnetwork/networkdb/networkdb.go
index e02fe794af..8676986e7d 100644
--- a/libnetwork/networkdb/networkdb.go
+++ b/libnetwork/networkdb/networkdb.go
@@ -286,6 +286,23 @@ func (nDB *NetworkDB) DeleteEntry(tname, nid, key string) error {
 	return nil
 }
 
+func (nDB *NetworkDB) deleteNetworkNodeEntries(deletedNode string) {
+	nDB.Lock()
+	for nid, nodes := range nDB.networkNodes {
+		updatedNodes := make([]string, 0, len(nodes))
+		for _, node := range nodes {
+			if node == deletedNode {
+				continue
+			}
+
+			updatedNodes = append(updatedNodes, node)
+		}
+
+		nDB.networkNodes[nid] = updatedNodes
+	}
+	nDB.Unlock()
+}
+
 func (nDB *NetworkDB) deleteNodeTableEntries(node string) {
 	nDB.Lock()
 	nDB.indexes[byTable].Walk(func(path string, v interface{}) bool {
@@ -359,6 +376,7 @@ func (nDB *NetworkDB) JoinNetwork(nid string) error {
 		RetransmitMult: 4,
 	}
 	nDB.networkNodes[nid] = append(nDB.networkNodes[nid], nDB.config.NodeName)
+	networkNodes := nDB.networkNodes[nid]
 	nDB.Unlock()
 
 	if err := nDB.sendNetworkEvent(nid, NetworkEventTypeJoin, ltime); err != nil {
@@ -366,7 +384,7 @@ func (nDB *NetworkDB) JoinNetwork(nid string) error {
 	}
 
 	logrus.Debugf("%s: joined network %s", nDB.config.NodeName, nid)
-	if _, err := nDB.bulkSync(nid, true); err != nil {
+	if _, err := nDB.bulkSync(nid, networkNodes, true); err != nil {
 		logrus.Errorf("Error bulk syncing while joining network %s: %v", nid, err)
 	}