From 59ea5c088b622078bcb6f6480465589084b82dbc Mon Sep 17 00:00:00 2001
From: Random-Liu <taotaotheripper@gmail.com>
Date: Sun, 10 Jul 2016 19:32:58 -0700
Subject: [PATCH] Change route controller to use patch to set node condition.

---
 pkg/controller/route/routecontroller.go | 56 ++++++++-----------------
 pkg/util/node/node.go                   | 21 ++++++++++
 2 files changed, 38 insertions(+), 39 deletions(-)

diff --git a/pkg/controller/route/routecontroller.go b/pkg/controller/route/routecontroller.go
index 54ce35072d6..179de8e9173 100644
--- a/pkg/controller/route/routecontroller.go
+++ b/pkg/controller/route/routecontroller.go
@@ -24,10 +24,12 @@ import (
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/errors"
 	"k8s.io/kubernetes/pkg/api/unversioned"
 	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/util/metrics"
+	nodeutil "k8s.io/kubernetes/pkg/util/node"
 	"k8s.io/kubernetes/pkg/util/wait"
 )
 
@@ -162,32 +164,22 @@ func (rc *RouteController) reconcile(nodes []api.Node, routes []*cloudprovider.R
 	return nil
 }
 
-func updateNetworkingCondition(node *api.Node, routeCreated bool) {
-	_, networkingCondition := api.GetNodeCondition(&node.Status, api.NodeNetworkUnavailable)
-	currentTime := unversioned.Now()
-	if routeCreated {
-		if networkingCondition != nil && networkingCondition.Status != api.ConditionFalse {
-			networkingCondition.Status = api.ConditionFalse
-			networkingCondition.Reason = "RouteCreated"
-			networkingCondition.Message = "RouteController created a route"
-			networkingCondition.LastTransitionTime = currentTime
-		} else if networkingCondition == nil {
-			node.Status.Conditions = append(node.Status.Conditions, api.NodeCondition{
+func (rc *RouteController) updateNetworkingCondition(nodeName string, routeCreated bool) error {
+	var err error
+	for i := 0; i < updateNodeStatusMaxRetries; i++ {
+		// Patch could also fail, even though the chance is very slim. So we still do
+		// patch in the retry loop.
+		currentTime := unversioned.Now()
+		if routeCreated {
+			err = nodeutil.SetNodeCondition(rc.kubeClient, nodeName, api.NodeCondition{
 				Type:               api.NodeNetworkUnavailable,
 				Status:             api.ConditionFalse,
 				Reason:             "RouteCreated",
 				Message:            "RouteController created a route",
 				LastTransitionTime: currentTime,
 			})
-		}
-	} else {
-		if networkingCondition != nil && networkingCondition.Status != api.ConditionTrue {
-			networkingCondition.Status = api.ConditionTrue
-			networkingCondition.Reason = "NoRouteCreated"
-			networkingCondition.Message = "RouteController failed to create a route"
-			networkingCondition.LastTransitionTime = currentTime
-		} else if networkingCondition == nil {
-			node.Status.Conditions = append(node.Status.Conditions, api.NodeCondition{
+		} else {
+			err = nodeutil.SetNodeCondition(rc.kubeClient, nodeName, api.NodeCondition{
 				Type:               api.NodeNetworkUnavailable,
 				Status:             api.ConditionTrue,
 				Reason:             "NoRouteCreated",
@@ -195,28 +187,14 @@ func updateNetworkingCondition(node *api.Node, routeCreated bool) {
 				LastTransitionTime: currentTime,
 			})
 		}
-	}
-}
-
-func (rc *RouteController) updateNetworkingCondition(nodeName string, routeCreated bool) error {
-	var err error
-	for i := 0; i < updateNodeStatusMaxRetries; i++ {
-		node, err := rc.kubeClient.Core().Nodes().Get(nodeName)
-		if err != nil {
-			glog.Errorf("Error geting node: %v", err)
-			continue
-		}
-		updateNetworkingCondition(node, routeCreated)
-		// TODO: Use Patch instead once #26381 is merged.
-		// See kubernetes/node-problem-detector#9 for details.
-		if _, err = rc.kubeClient.Core().Nodes().UpdateStatus(node); err == nil {
+		if err == nil {
 			return nil
 		}
-		if i+1 < updateNodeStatusMaxRetries {
-			glog.Errorf("Error updating node %s, retrying: %v", node.Name, err)
-		} else {
-			glog.Errorf("Error updating node %s: %v", node.Name, err)
+		if i == updateNodeStatusMaxRetries || !errors.IsConflict(err) {
+			glog.Errorf("Error updating node %s: %v", nodeName, err)
+			return err
 		}
+		glog.Errorf("Error updating node %s, retrying: %v", nodeName, err)
 	}
 	return err
 }
diff --git a/pkg/util/node/node.go b/pkg/util/node/node.go
index 66f916c94fe..5d25d7fea79 100644
--- a/pkg/util/node/node.go
+++ b/pkg/util/node/node.go
@@ -17,14 +17,17 @@ limitations under the License.
 package node
 
 import (
+	"encoding/json"
 	"fmt"
 	"net"
 	"os/exec"
 	"strings"
+	"time"
 
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/unversioned"
+	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 )
 
 func GetHostname(hostnameOverride string) string {
@@ -81,3 +84,21 @@ func GetZoneKey(node *api.Node) string {
 	// As a nice side-benefit, the null character is not printed by fmt.Print or glog
 	return region + ":\x00:" + failureDomain
 }
+
+// SetNodeCondition updates specific node condition with patch operation.
+func SetNodeCondition(c clientset.Interface, node string, condition api.NodeCondition) error {
+	generatePatch := func(condition api.NodeCondition) ([]byte, error) {
+		raw, err := json.Marshal(&[]api.NodeCondition{condition})
+		if err != nil {
+			return nil, err
+		}
+		return []byte(fmt.Sprintf(`{"status":{"conditions":%s}}`, raw)), nil
+	}
+	condition.LastHeartbeatTime = unversioned.NewTime(time.Now())
+	patch, err := generatePatch(condition)
+	if err != nil {
+		return nil
+	}
+	_, err = c.Core().Nodes().PatchStatus(node, patch)
+	return err
+}