checkLimitsForResolvConf for the pod create and update events instead of checking period

pkg/kubelet/BUILD

@@ -181,6 +181,7 @@ go_test(
         "//pkg/kubelet/images:go_default_library",
         "//pkg/kubelet/lifecycle:go_default_library",
         "//pkg/kubelet/logs:go_default_library",
+        "//pkg/kubelet/network/dns:go_default_library",
         "//pkg/kubelet/pleg:go_default_library",
         "//pkg/kubelet/pod:go_default_library",
         "//pkg/kubelet/pod/testing:go_default_library",

pkg/kubelet/kubelet.go

@@ -1384,11 +1384,6 @@ func (kl *Kubelet) Run(updates <-chan kubetypes.PodUpdate) {
 	// handled by pod workers).
 	go wait.Until(kl.podKiller, 1*time.Second, wait.NeverStop)
 
-	// Start gorouting responsible for checking limits in resolv.conf
-	if kl.dnsConfigurer.ResolverConfig != "" {
-		go wait.Until(func() { kl.dnsConfigurer.CheckLimitsForResolvConf() }, 30*time.Second, wait.NeverStop)
-	}
-
 	// Start component sync loops.
 	kl.statusManager.Start()
 	kl.probeManager.Start()
@@ -1978,6 +1973,10 @@ func (kl *Kubelet) HandlePodAdditions(pods []*v1.Pod) {
 	start := kl.clock.Now()
 	sort.Sort(sliceutils.PodsByCreationTime(pods))
 	for _, pod := range pods {
+		// Responsible for checking limits in resolv.conf
+		if kl.dnsConfigurer != nil && kl.dnsConfigurer.ResolverConfig != "" {
+			kl.dnsConfigurer.CheckLimitsForResolvConf()
+		}
 		existingPods := kl.podManager.GetPods()
 		// Always add the pod to the pod manager. Kubelet relies on the pod
 		// manager as the source of truth for the desired state. If a pod does
@@ -2015,6 +2014,10 @@ func (kl *Kubelet) HandlePodAdditions(pods []*v1.Pod) {
 func (kl *Kubelet) HandlePodUpdates(pods []*v1.Pod) {
 	start := kl.clock.Now()
 	for _, pod := range pods {
+		// Responsible for checking limits in resolv.conf
+		if kl.dnsConfigurer != nil && kl.dnsConfigurer.ResolverConfig != "" {
+			kl.dnsConfigurer.CheckLimitsForResolvConf()
+		}
 		kl.podManager.UpdatePod(pod)
 		if kubepod.IsMirrorPod(pod) {
 			kl.handleMirrorPod(pod, start)

pkg/kubelet/kubelet_test.go

@@ -51,6 +51,7 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/images"
 	"k8s.io/kubernetes/pkg/kubelet/lifecycle"
 	"k8s.io/kubernetes/pkg/kubelet/logs"
+	"k8s.io/kubernetes/pkg/kubelet/network/dns"
 	"k8s.io/kubernetes/pkg/kubelet/pleg"
 	kubepod "k8s.io/kubernetes/pkg/kubelet/pod"
 	podtest "k8s.io/kubernetes/pkg/kubelet/pod/testing"
@@ -481,6 +482,16 @@ func TestHandlePortConflicts(t *testing.T) {
 		},
 	}}
 
+	recorder := record.NewFakeRecorder(20)
+	nodeRef := &v1.ObjectReference{
+		Kind:      "Node",
+		Name:      string("testNode"),
+		UID:       types.UID("testNode"),
+		Namespace: "",
+	}
+	testClusterDNSDomain := "TEST"
+	kl.dnsConfigurer = dns.NewConfigurer(recorder, nodeRef, nil, nil, testClusterDNSDomain, "")
+
 	spec := v1.PodSpec{NodeName: string(kl.nodeName), Containers: []v1.Container{{Ports: []v1.ContainerPort{{HostPort: 80}}}}}
 	pods := []*v1.Pod{
 		podWithUIDNameNsSpec("123456789", "newpod", "foo", spec),
@@ -518,6 +529,16 @@ func TestHandleHostNameConflicts(t *testing.T) {
 		},
 	}}
 
+	recorder := record.NewFakeRecorder(20)
+	nodeRef := &v1.ObjectReference{
+		Kind:      "Node",
+		Name:      string("testNode"),
+		UID:       types.UID("testNode"),
+		Namespace: "",
+	}
+	testClusterDNSDomain := "TEST"
+	kl.dnsConfigurer = dns.NewConfigurer(recorder, nodeRef, nil, nil, testClusterDNSDomain, "")
+
 	// default NodeName in test is 127.0.0.1
 	pods := []*v1.Pod{
 		podWithUIDNameNsSpec("123456789", "notfittingpod", "foo", v1.PodSpec{NodeName: "127.0.0.2"}),
@@ -551,6 +572,17 @@ func TestHandleNodeSelector(t *testing.T) {
 		},
 	}
 	kl.nodeInfo = testNodeInfo{nodes: nodes}
+
+	recorder := record.NewFakeRecorder(20)
+	nodeRef := &v1.ObjectReference{
+		Kind:      "Node",
+		Name:      string("testNode"),
+		UID:       types.UID("testNode"),
+		Namespace: "",
+	}
+	testClusterDNSDomain := "TEST"
+	kl.dnsConfigurer = dns.NewConfigurer(recorder, nodeRef, nil, nil, testClusterDNSDomain, "")
+
 	pods := []*v1.Pod{
 		podWithUIDNameNsSpec("123456789", "podA", "foo", v1.PodSpec{NodeSelector: map[string]string{"key": "A"}}),
 		podWithUIDNameNsSpec("987654321", "podB", "foo", v1.PodSpec{NodeSelector: map[string]string{"key": "B"}}),
@@ -582,6 +614,16 @@ func TestHandleMemExceeded(t *testing.T) {
 	}
 	kl.nodeInfo = testNodeInfo{nodes: nodes}
 
+	recorder := record.NewFakeRecorder(20)
+	nodeRef := &v1.ObjectReference{
+		Kind:      "Node",
+		Name:      string("testNode"),
+		UID:       types.UID("testNode"),
+		Namespace: "",
+	}
+	testClusterDNSDomain := "TEST"
+	kl.dnsConfigurer = dns.NewConfigurer(recorder, nodeRef, nil, nil, testClusterDNSDomain, "")
+
 	spec := v1.PodSpec{NodeName: string(kl.nodeName),
 		Containers: []v1.Container{{Resources: v1.ResourceRequirements{
 			Requests: v1.ResourceList{
@@ -668,6 +710,16 @@ func TestHandlePluginResources(t *testing.T) {
 	kl.admitHandlers = lifecycle.PodAdmitHandlers{}
 	kl.admitHandlers.AddPodAdmitHandler(lifecycle.NewPredicateAdmitHandler(kl.getNodeAnyWay, lifecycle.NewAdmissionFailureHandlerStub(), updatePluginResourcesFunc))
 
+	recorder := record.NewFakeRecorder(20)
+	nodeRef := &v1.ObjectReference{
+		Kind:      "Node",
+		Name:      string("testNode"),
+		UID:       types.UID("testNode"),
+		Namespace: "",
+	}
+	testClusterDNSDomain := "TEST"
+	kl.dnsConfigurer = dns.NewConfigurer(recorder, nodeRef, nil, nil, testClusterDNSDomain, "")
+
 	// pod requiring adjustedResource can be successfully allocated because updatePluginResourcesFunc
 	// adjusts node.allocatableResource for this resource to a sufficient value.
 	fittingPodSpec := v1.PodSpec{NodeName: string(kl.nodeName),

pkg/kubelet/network/dns/dns.go

@@ -156,7 +156,7 @@ func (c *Configurer) CheckLimitsForResolvConf() {
 	f, err := os.Open(c.ResolverConfig)
 	if err != nil {
 		c.recorder.Event(c.nodeRef, v1.EventTypeWarning, "CheckLimitsForResolvConf", err.Error())
-		glog.Error("CheckLimitsForResolvConf: " + err.Error())
+		glog.V(4).Infof("CheckLimitsForResolvConf: " + err.Error())
 		return
 	}
 	defer f.Close()
@@ -164,7 +164,7 @@ func (c *Configurer) CheckLimitsForResolvConf() {
 	_, hostSearch, _, err := parseResolvConf(f)
 	if err != nil {
 		c.recorder.Event(c.nodeRef, v1.EventTypeWarning, "CheckLimitsForResolvConf", err.Error())
-		glog.Error("CheckLimitsForResolvConf: " + err.Error())
+		glog.V(4).Infof("CheckLimitsForResolvConf: " + err.Error())
 		return
 	}
 
@@ -177,14 +177,14 @@ func (c *Configurer) CheckLimitsForResolvConf() {
 	if len(hostSearch) > domainCountLimit {
 		log := fmt.Sprintf("Resolv.conf file '%s' contains search line consisting of more than %d domains!", c.ResolverConfig, domainCountLimit)
 		c.recorder.Event(c.nodeRef, v1.EventTypeWarning, "CheckLimitsForResolvConf", log)
-		glog.Error("CheckLimitsForResolvConf: " + log)
+		glog.V(4).Infof("CheckLimitsForResolvConf: " + log)
 		return
 	}
 
 	if len(strings.Join(hostSearch, " ")) > validation.MaxDNSSearchListChars {
 		log := fmt.Sprintf("Resolv.conf file '%s' contains search line which length is more than allowed %d chars!", c.ResolverConfig, validation.MaxDNSSearchListChars)
 		c.recorder.Event(c.nodeRef, v1.EventTypeWarning, "CheckLimitsForResolvConf", log)
-		glog.Error("CheckLimitsForResolvConf: " + log)
+		glog.V(4).Infof("CheckLimitsForResolvConf: " + log)
 		return
 	}