add federations translation

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

@@ -46,6 +46,7 @@ const (
 	KubeDNSServiceAccountName  = "kube-dns"
 	kubeDNSStubDomain          = "stubDomains"
 	kubeDNSUpstreamNameservers = "upstreamNameservers"
+	kubeDNSFederation          = "federations"
 )
 
 // EnsureDNSAddon creates the kube-dns or CoreDNS addon
@@ -160,12 +161,17 @@ func coreDNSAddon(cfg *kubeadmapi.MasterConfiguration, client clientset.Interfac
 	if err != nil {
 		return err
 	}
+	coreDNSDomain := cfg.Networking.DNSDomain
+	federations, err := translateFederationsofKubeDNSToCoreDNS(kubeDNSFederation, coreDNSDomain, kubeDNSConfigMap)
+	if err != nil {
+		return err
+	}
 
 	// Get the config file for CoreDNS
-	coreDNSConfigMapBytes, err := kubeadmutil.ParseTemplate(CoreDNSConfigMap, struct{ DNSDomain, ServiceCIDR, UpstreamNameserver, StubDomain string }{
+	coreDNSConfigMapBytes, err := kubeadmutil.ParseTemplate(CoreDNSConfigMap, struct{ DNSDomain, UpstreamNameserver, Federation, StubDomain string }{
-		ServiceCIDR:        cfg.Networking.ServiceSubnet,
+		DNSDomain:          coreDNSDomain,
-		DNSDomain:          cfg.Networking.DNSDomain,
 		UpstreamNameserver: upstreamNameserver,
+		Federation:         federations,
 		StubDomain:         stubDomain,
 	})
 	if err != nil {
@@ -273,7 +279,7 @@ func createDNSService(dnsService *v1.Service, serviceBytes []byte, client client
 func translateStubDomainOfKubeDNSToProxyCoreDNS(dataField string, kubeDNSConfigMap *v1.ConfigMap) (string, error) {
 	if proxy, ok := kubeDNSConfigMap.Data[dataField]; ok {
 		stubDomainData := make(map[string][]string)
-		proxyStanzaList := coreDNSProxyStanzaPrefix
+		proxyStanzaList := coreDNSStanzaPrefix
 
 		err := json.Unmarshal([]byte(proxy), &stubDomainData)
 		if err != nil {
@@ -304,3 +310,24 @@ func translateUpstreamNameServerOfKubeDNSToUpstreamProxyCoreDNS(dataField string
 	}
 	return kubetypes.ResolvConfDefault, nil
 }
+
+// translateFederationofKubeDNSToCoreDNS translates Federations Data in kube-dns ConfigMap
+// to Federation for CoreDNS Corefile.
+func translateFederationsofKubeDNSToCoreDNS(dataField, coreDNSDomain string, kubeDNSConfigMap *v1.ConfigMap) (string, error) {
+	if federation, ok := kubeDNSConfigMap.Data[dataField]; ok {
+		federationData := make(map[string]string)
+
+		err := json.Unmarshal([]byte(federation), &federationData)
+		if err != nil {
+			return "", fmt.Errorf("failed to parse JSON from kube-dns ConfigMap: %v", err)
+		}
+		federationStanzaList := coreDNSStanzaPrefix + coreDNSFederation + coreDNSDomain + coreDNSFederationStanzaPrefix
+		var federationStanzaContents string
+		for name, domain := range federationData {
+			federationStanzaContents = federationStanzaContents + coreDNSFederationStanzaMid + name + " " + domain
+		}
+		federationStanzaList = federationStanzaList + federationStanzaContents + coreDNSFederationStanzaSuffix
+		return federationStanzaList, nil
+	}
+	return "", nil
+}

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

@@ -130,9 +130,9 @@ func TestCompileManifests(t *testing.T) {
 		},
 		{
 			manifest: CoreDNSConfigMap,
-			data: struct{ DNSDomain, ServiceCIDR, UpstreamNameserver, StubDomain string }{
+			data: struct{ DNSDomain, Federation, UpstreamNameserver, StubDomain string }{
 				DNSDomain:          "foo",
-				ServiceCIDR:        "foo",
+				Federation:         "foo",
 				UpstreamNameserver: "foo",
 				StubDomain:         "foo",
 			},
@@ -311,3 +311,63 @@ func TestTranslateUpstreamKubeDNSToCoreDNS(t *testing.T) {
 		}
 	}
 }
+
+func TestTranslateFederationKubeDNSToCoreDNS(t *testing.T) {
+	testCases := []struct {
+		configMap *v1.ConfigMap
+		expect    string
+	}{
+		{
+			configMap: &v1.ConfigMap{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "kube-dns",
+					Namespace: "kube-system",
+				},
+				Data: map[string]string{
+					"federations":         `{"foo" : "foo.feddomain.com", "bar" : "bar.feddomain.com"}`,
+					"stubDomains":         `{"foo.com" : ["1.2.3.4:5300","3.3.3.3"], "my.cluster.local" : ["2.3.4.5"]}`,
+					"upstreamNameservers": `["8.8.8.8", "8.8.4.4"]`,
+				},
+			},
+
+			expect: `
+    federation cluster.local {
+       foo foo.feddomain.com
+       bar bar.feddomain.com
+    }`,
+		},
+		{
+			configMap: &v1.ConfigMap{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "kubedns",
+					Namespace: "kube-system",
+				},
+			},
+
+			expect: "",
+		},
+		{
+			configMap: &v1.ConfigMap{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "kube-dns",
+					Namespace: "kube-system",
+				},
+				Data: map[string]string{
+					"stubDomains":         `{"foo.com" : ["1.2.3.4:5300"], "my.cluster.local" : ["2.3.4.5"]}`,
+					"upstreamNameservers": `["8.8.8.8", "8.8.4.4"]`,
+				},
+			},
+
+			expect: "",
+		},
+	}
+	for _, testCase := range testCases {
+		out, err := translateFederationsofKubeDNSToCoreDNS(kubeDNSFederation, "cluster.local", testCase.configMap)
+		if err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if !strings.Contains(out, testCase.expect) {
+			t.Errorf("expected to find %q in output: %q", testCase.expect, out)
+		}
+	}
+}

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

@@ -307,11 +307,11 @@ data:
     .:53 {
         errors
         health
-        kubernetes {{ .DNSDomain }} {{ .ServiceCIDR }} {
+        kubernetes {{ .DNSDomain }} in-addr.arpa ip6.arpa {
            pods insecure
            upstream {{ .UpstreamNameserver }}
            fallthrough in-addr.arpa ip6.arpa
-        }
+        }{{ .Federation }}
         prometheus :9153
         proxy . {{ .UpstreamNameserver }}
         cache 30
@@ -359,14 +359,15 @@ metadata:
   namespace: kube-system
 `
 	// coreDNSProxyDefaultPort, coreDNSCorefileDefaultData, coreDNSProxyStanzaSuffix is used in the translation of configMap of kube-dns to CoreDNS.
-	coreDNSProxyStanzaPrefix = `
+	coreDNSStanzaPrefix        = "\n    "
-    `
 	coreDNSProxyDefaultPort    = `:53`
 	coreDNSCorefileDefaultData = ` {
         errors
         cache 30
         proxy . `
-	coreDNSProxyStanzaSuffix = `
+	coreDNSProxyStanzaSuffix      = "\n    }\n    "
-    }
+	coreDNSFederation             = "federation "
-    `
+	coreDNSFederationStanzaPrefix = " {"
+	coreDNSFederationStanzaMid    = "\n       "
+	coreDNSFederationStanzaSuffix = "\n    }"
 )