avoid deleting cbr0 address due to subnet string mismatch

pkg/kubelet/network/kubenet/kubenet_linux.go

@@ -40,6 +40,7 @@ import (
 	utilerrors "k8s.io/kubernetes/pkg/util/errors"
 	utilexec "k8s.io/kubernetes/pkg/util/exec"
 	utiliptables "k8s.io/kubernetes/pkg/util/iptables"
+	utilnet "k8s.io/kubernetes/pkg/util/net"
 	utilsets "k8s.io/kubernetes/pkg/util/sets"
 	utilsysctl "k8s.io/kubernetes/pkg/util/sysctl"
 
@@ -228,7 +229,7 @@ func (plugin *kubenetNetworkPlugin) Event(name string, details map[string]interf
 
 			// Ensure cbr0 has no conflicting addresses; CNI's 'bridge'
 			// plugin will bail out if the bridge has an unexpected one
-			plugin.clearBridgeAddressesExcept(cidr.IP.String())
+			plugin.clearBridgeAddressesExcept(cidr)
 		}
 	}
 
@@ -237,7 +238,7 @@ func (plugin *kubenetNetworkPlugin) Event(name string, details map[string]interf
 	}
 }
 
-func (plugin *kubenetNetworkPlugin) clearBridgeAddressesExcept(keep string) {
+func (plugin *kubenetNetworkPlugin) clearBridgeAddressesExcept(keep *net.IPNet) {
 	bridge, err := netlink.LinkByName(BridgeName)
 	if err != nil {
 		return
@@ -249,8 +250,8 @@ func (plugin *kubenetNetworkPlugin) clearBridgeAddressesExcept(keep string) {
 	}
 
 	for _, addr := range addrs {
-		if addr.IPNet.String() != keep {
-			glog.V(5).Infof("Removing old address %s from %s", addr.IPNet.String(), BridgeName)
+		if !utilnet.IPNetEqual(addr.IPNet, keep) {
+			glog.V(2).Infof("Removing old address %s from %s", addr.IPNet.String(), BridgeName)
 			netlink.AddrDel(bridge, &addr)
 		}
 	}

pkg/util/net/util.go

+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"net"
+	"reflect"
+)
+
+// IPNetEqual checks if the two input IPNets are representing the same subnet.
+// For example,
+//	10.0.0.1/24 and 10.0.0.0/24 are the same subnet.
+//	10.0.0.1/24 and 10.0.0.0/25 are not the same subnet.
+func IPNetEqual(ipnet1, ipnet2 *net.IPNet) bool {
+	if ipnet1 == nil || ipnet2 == nil {
+		return false
+	}
+	if reflect.DeepEqual(ipnet1.Mask, ipnet2.Mask) && ipnet1.Contains(ipnet2.IP) && ipnet2.Contains(ipnet1.IP) {
+		return true
+	}
+	return false
+}

pkg/util/net/util_test.go

+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package net
+
+import (
+	"net"
+	"testing"
+)
+
+func getIPNet(cidr string) *net.IPNet {
+	_, ipnet, _ := net.ParseCIDR(cidr)
+	return ipnet
+}
+
+func TestIPNetEqual(t *testing.T) {
+	testCases := []struct {
+		ipnet1 *net.IPNet
+		ipnet2 *net.IPNet
+		expect bool
+	}{
+		//null case
+		{
+			getIPNet("10.0.0.1/24"),
+			getIPNet(""),
+			false,
+		},
+		{
+			getIPNet("10.0.0.0/24"),
+			getIPNet("10.0.0.0/24"),
+			true,
+		},
+		{
+			getIPNet("10.0.0.0/24"),
+			getIPNet("10.0.0.1/24"),
+			true,
+		},
+		{
+			getIPNet("10.0.0.0/25"),
+			getIPNet("10.0.0.0/24"),
+			false,
+		},
+		{
+			getIPNet("10.0.1.0/24"),
+			getIPNet("10.0.0.0/24"),
+			false,
+		},
+	}
+
+	for _, tc := range testCases {
+		if tc.expect != IPNetEqual(tc.ipnet1, tc.ipnet2) {
+			t.Errorf("Expect equality of %s and %s be to %v", tc.ipnet1.String(), tc.ipnet2.String(), tc.expect)
+		}
+	}
+}