Adds support for v4/v6 loopback dns bind address.

cmd/kubeadm/app/phases/addons/dns/dns.go

@@ -51,13 +51,27 @@ func EnsureDNSAddon(cfg *kubeadmapi.MasterConfiguration, client clientset.Interf
 		return err
 	}
 
+	dnsip, err := getDNSIP(client)
+	if err != nil {
+		return err
+	}
+
+	var dnsBindAddr string
+	if dnsip.To16() != nil {
+		dnsBindAddr = "::1"
+	} else {
+		dnsBindAddr = "127.0.0.1"
+	}
+
 	// Get the YAML manifest conditionally based on the k8s version
 	kubeDNSDeploymentBytes := GetKubeDNSManifest(k8sVersion)
-	dnsDeploymentBytes, err := kubeadmutil.ParseTemplate(kubeDNSDeploymentBytes, struct{ ImageRepository, Arch, Version, DNSDomain, DNSProbeType, MasterTaintKey string }{
+	dnsDeploymentBytes, err := kubeadmutil.ParseTemplate(kubeDNSDeploymentBytes,
+		struct{ ImageRepository, Arch, Version, DNSBindAddr, DNSDomain, DNSProbeType, MasterTaintKey string }{
 			ImageRepository: cfg.ImageRepository,
 			Arch:            runtime.GOARCH,
 			// Get the kube-dns version conditionally based on the k8s version
 			Version:        GetKubeDNSVersion(k8sVersion),
+			DNSBindAddr:    dnsBindAddr,
 			DNSDomain:      cfg.Networking.DNSDomain,
 			DNSProbeType:   GetKubeDNSProbeType(k8sVersion),
 			MasterTaintKey: kubeadmconstants.LabelNodeRoleMaster,
@@ -66,11 +80,6 @@ func EnsureDNSAddon(cfg *kubeadmapi.MasterConfiguration, client clientset.Interf
 		return fmt.Errorf("error when parsing kube-dns deployment template: %v", err)
 	}
 
-	dnsip, err := getDNSIP(client)
-	if err != nil {
-		return err
-	}
-
 	dnsServiceBytes, err := kubeadmutil.ParseTemplate(KubeDNSService, struct{ DNSIP string }{
 		DNSIP: dnsip.String(),
 	})

cmd/kubeadm/app/phases/addons/dns/dns_test.go

@@ -91,10 +91,11 @@ func TestCompileManifests(t *testing.T) {
 	}{
 		{
 			manifest: v180AndAboveKubeDNSDeployment,
-			data: struct{ ImageRepository, Arch, Version, DNSDomain, DNSProbeType, MasterTaintKey string }{
+			data: struct{ ImageRepository, Arch, Version, DNSBindAddr, DNSDomain, DNSProbeType, MasterTaintKey string }{
 				ImageRepository: "foo",
 				Arch:            "foo",
 				Version:         "foo",
+				DNSBindAddr:     "foo",
 				DNSDomain:       "foo",
 				DNSProbeType:    "foo",
 				MasterTaintKey:  "foo",

cmd/kubeadm/app/phases/addons/dns/manifests.go

@@ -123,9 +123,9 @@ spec:
         - --cache-size=1000
         - --no-negcache
         - --log-facility=-
-        - --server=/{{ .DNSDomain }}/127.0.0.1#10053
+        - --server=/{{ .DNSDomain }}/{{ .DNSBindAddr }}#10053
-        - --server=/in-addr.arpa/127.0.0.1#10053
+        - --server=/in-addr.arpa/{{ .DNSBindAddr }}#10053
-        - --server=/ip6.arpa/127.0.0.1#10053
+        - --server=/ip6.arpa/{{ .DNSBindAddr }}#10053
         ports:
         - containerPort: 53
           name: dns
@@ -156,8 +156,8 @@ spec:
         args:
         - --v=2
         - --logtostderr
-        - --probe=kubedns,127.0.0.1:10053,kubernetes.default.svc.{{ .DNSDomain }},5,{{ .DNSProbeType }}
+        - --probe=kubedns,{{ .DNSBindAddr }}:10053,kubernetes.default.svc.{{ .DNSDomain }},5,{{ .DNSProbeType }}
-        - --probe=dnsmasq,127.0.0.1:53,kubernetes.default.svc.{{ .DNSDomain }},5,{{ .DNSProbeType }}
+        - --probe=dnsmasq,{{ .DNSBindAddr }}:53,kubernetes.default.svc.{{ .DNSDomain }},5,{{ .DNSProbeType }}
         ports:
         - containerPort: 10054
           name: metrics