Merge pull request #26114 from ArtfulCoder/dnsport

Add dnsmasq as a DNS cache in kube-dns pod
kubernetes · May 26, 2016 · 965e8dc · 965e8dc
2 parents d3d6185 + 10f9789
commit 965e8dc
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Showing 7 changed files with 41 additions and 22 deletions.
diff --git a/build/kube-dns/Makefile b/build/kube-dns/Makefile
@@ -22,7 +22,7 @@
 # Default registry, arch and tag. This can be overwritten by arguments to make
 PLATFORM?=linux
 ARCH?=amd64
-TAG?=1.0
+TAG?=1.1
 REGISTRY?=gcr.io/google_containers
 
 GOLANG_VERSION=1.6

diff --git a/cluster/saltbase/salt/kube-dns/kubedns-rc.yaml.in b/cluster/saltbase/salt/kube-dns/kubedns-rc.yaml.in
@@ -21,7 +21,7 @@ spec:
     spec:
       containers:
       - name: kubedns
-        image: gcr.io/google_containers/kubedns-amd64:1.0
+        image: gcr.io/google_containers/kubedns-amd64:1.1
         resources:
           # TODO: Set memory limits when we've profiled the container for large
           # clusters, then set request = limit to keep this container in
@@ -54,6 +54,20 @@ spec:
         args:
         # command = "/kube-dns"
         - --domain={{ pillar['dns_domain'] }}.
+        - --dns-port=10053
+        ports:
+        - containerPort: 10053
+          name: dns-local
+          protocol: UDP
+        - containerPort: 10053
+          name: dns-tcp-local
+          protocol: TCP
+      - name: dnsmasq
+        image: gcr.io/google_containers/dnsmasq:1.1
+        args:
+        - --cache-size=1000
+        - --no-resolv
+        - --server=127.0.0.1#10053
         ports:
         - containerPort: 53
           name: dns

diff --git a/cmd/kube-dns/app/options/options.go b/cmd/kube-dns/app/options/options.go
@@ -33,6 +33,7 @@ type KubeDNSConfig struct {
 	KubeConfigFile string
 	KubeMasterURL  string
 	HealthzPort    int
+	DNSPort        int
 	// Federations maps federation names to their registered domain names.
 	Federations map[string]string
 }
@@ -43,6 +44,7 @@ func NewKubeDNSConfig() *KubeDNSConfig {
 		KubeConfigFile: "",
 		KubeMasterURL:  "",
 		HealthzPort:    8081,
+		DNSPort:        53,
 		Federations:    make(map[string]string),
 	}
 }
@@ -140,5 +142,6 @@ func (s *KubeDNSConfig) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.KubeConfigFile, "kubecfg-file", s.KubeConfigFile, "Location of kubecfg file for access to kubernetes master service; --kube-master-url overrides the URL part of this; if neither this nor --kube-master-url are provided, defaults to service account tokens")
 	fs.Var(kubeMasterURLVar{&s.KubeMasterURL}, "kube-master-url", "URL to reach kubernetes master. Env variables in this flag will be expanded.")
 	fs.IntVar(&s.HealthzPort, "healthz-port", s.HealthzPort, "port on which to serve a kube-dns HTTP readiness probe.")
+	fs.IntVar(&s.DNSPort, "dns-port", s.DNSPort, "port on which to serve DNS requests.")
 	fs.Var(federationsVar{s.Federations}, "federations", "a comma separated list of the federation names and their corresponding domain names to which this cluster belongs. Example: \"myfederation1=example.com,myfederation2=example2.com,myfederation3=example.com\"")
 }
diff --git a/cmd/kube-dns/app/server.go b/cmd/kube-dns/app/server.go
@@ -28,7 +28,7 @@ import (
 	"github.com/skynetservices/skydns/server"
 	"k8s.io/kubernetes/cmd/kube-dns/app/options"
 	"k8s.io/kubernetes/pkg/api/unversioned"
-	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_3"
+	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 	"k8s.io/kubernetes/pkg/client/restclient"
 	kclientcmd "k8s.io/kubernetes/pkg/client/unversioned/clientcmd"
 	kdns "k8s.io/kubernetes/pkg/dns"
@@ -38,6 +38,7 @@ type KubeDNSServer struct {
 	// DNS domain name.
 	domain      string
 	healthzPort int
+	dnsPort     int
 	kd          *kdns.KubeDNS
 }
 
@@ -51,6 +52,7 @@ func NewKubeDNSServerDefault(config *options.KubeDNSConfig) *KubeDNSServer {
 		glog.Fatalf("Failed to create a kubernetes client: %v", err)
 	}
 	ks.healthzPort = config.HealthzPort
+	ks.dnsPort = config.DNSPort
 	ks.kd = kdns.NewKubeDNS(kubeClient, config.ClusterDomain, config.Federations)
 	return &ks
 }
@@ -124,7 +126,8 @@ func setupSignalHandlers() {
 }
 
 func (d *KubeDNSServer) startSkyDNSServer() {
-	skydnsConfig := &server.Config{Domain: d.domain, DnsAddr: "0.0.0.0:53"}
+	glog.Infof("Starting SkyDNS server. Listening on port:%d", d.dnsPort)
+	skydnsConfig := &server.Config{Domain: d.domain, DnsAddr: fmt.Sprintf("0.0.0.0:%d", d.dnsPort)}
 	server.SetDefaults(skydnsConfig)
 	s := server.New(d.kd, skydnsConfig)
 	if err := metrics.Metrics(); err != nil {

diff --git a/hack/verify-flags/known-flags.txt b/hack/verify-flags/known-flags.txt
@@ -90,6 +90,7 @@ deployment-label-key
 deserialization-cache-size
 dest-file
 disable-filter
+dns-port
 docker-email
 docker-endpoint
 docker-exec-handler

diff --git a/pkg/dns/dns.go b/pkg/dns/dns.go
@@ -31,9 +31,8 @@ import (
 	kapi "k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/endpoints"
 	"k8s.io/kubernetes/pkg/api/unversioned"
-	v1 "k8s.io/kubernetes/pkg/api/v1"
 	kcache "k8s.io/kubernetes/pkg/client/cache"
-	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_3"
+	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
 	kframework "k8s.io/kubernetes/pkg/controller/framework"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util/validation"
@@ -129,7 +128,7 @@ func (kd *KubeDNS) Start() {
 	kd.waitForKubernetesService()
 }
 
-func (kd *KubeDNS) waitForKubernetesService() (svc *v1.Service) {
+func (kd *KubeDNS) waitForKubernetesService() (svc *kapi.Service) {
 	name := fmt.Sprintf("%v/%v", kapi.NamespaceDefault, kubernetesSvcName)
 	glog.Infof("Waiting for service: %v", name)
 	var err error
@@ -158,13 +157,13 @@ func (kd *KubeDNS) setServicesStore() {
 	kd.servicesStore, kd.serviceController = kframework.NewInformer(
 		&kcache.ListWatch{
 			ListFunc: func(options kapi.ListOptions) (runtime.Object, error) {
-				return kd.kubeClient.Core().Services(v1.NamespaceAll).List(options)
+				return kd.kubeClient.Core().Services(kapi.NamespaceAll).List(options)
 			},
 			WatchFunc: func(options kapi.ListOptions) (watch.Interface, error) {
-				return kd.kubeClient.Core().Services(v1.NamespaceAll).Watch(options)
+				return kd.kubeClient.Core().Services(kapi.NamespaceAll).Watch(options)
 			},
 		},
-		&v1.Service{},
+		&kapi.Service{},
 		resyncPeriod,
 		kframework.ResourceEventHandlerFuncs{
 			AddFunc:    kd.newService,
@@ -179,13 +178,13 @@ func (kd *KubeDNS) setEndpointsStore() {
 	kd.endpointsStore, kd.endpointsController = kframework.NewInformer(
 		&kcache.ListWatch{
 			ListFunc: func(options kapi.ListOptions) (runtime.Object, error) {
-				return kd.kubeClient.Core().Endpoints(v1.NamespaceAll).List(options)
+				return kd.kubeClient.Core().Endpoints(kapi.NamespaceAll).List(options)
 			},
 			WatchFunc: func(options kapi.ListOptions) (watch.Interface, error) {
-				return kd.kubeClient.Core().Endpoints(v1.NamespaceAll).Watch(options)
+				return kd.kubeClient.Core().Endpoints(kapi.NamespaceAll).Watch(options)
 			},
 		},
-		&v1.Endpoints{},
+		&kapi.Endpoints{},
 		resyncPeriod,
 		kframework.ResourceEventHandlerFuncs{
 			AddFunc: kd.handleEndpointAdd,
@@ -565,12 +564,12 @@ func (kd *KubeDNS) federationRecords(queryPath []string) ([]skymsg.Service, erro
 // simpler approach here.
 // Also note that zone here means the zone in cloud provider terminology, not the DNS zone.
 func (kd *KubeDNS) getClusterZone() (string, error) {
-	var node *v1.Node
+	var node *kapi.Node
 
 	objs := kd.nodesStore.List()
 	if len(objs) > 0 {
 		var ok bool
-		if node, ok = objs[0].(*v1.Node); !ok {
+		if node, ok = objs[0].(*kapi.Node); !ok {
 			return "", fmt.Errorf("expected node object, got: %T", objs[0])
 		}
 	} else {

diff --git a/pkg/dns/dns_test.go b/pkg/dns/dns_test.go
@@ -29,9 +29,8 @@ import (
 	"github.com/stretchr/testify/require"
 	kapi "k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/unversioned"
-	v1 "k8s.io/kubernetes/pkg/api/v1"
 	"k8s.io/kubernetes/pkg/client/cache"
-	fake "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_3/fake"
+	fake "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset/fake"
 )
 
 const (
@@ -276,17 +275,17 @@ func testInvalidFederationQueries(t *testing.T, kd *KubeDNS) {
 	}
 }
 
-func newNodes() *v1.NodeList {
-	return &v1.NodeList{
-		Items: []v1.Node{
+func newNodes() *kapi.NodeList {
+	return &kapi.NodeList{
+		Items: []kapi.Node{
 			// Node without annotation.
 			{
-				ObjectMeta: v1.ObjectMeta{
+				ObjectMeta: kapi.ObjectMeta{
 					Name: "testnode-0",
 				},
 			},
 			{
-				ObjectMeta: v1.ObjectMeta{
+				ObjectMeta: kapi.ObjectMeta{
 					Name: "testnode-1",
 					Annotations: map[string]string{
 						// Note: The zone name here is an arbitrary string and doesn't exactly follow the