Use configured DNS domain in bootstrapper kubeadm templates

Fixes #4963

Following are the file changes:

kubeadm.go --> Add DNSDomain as one the field
kubeadm_test.go --> Add new test case to test the dns changes
templates.go --> Add the new DNSDomain into the template

Add new testdata for the kubeadm_test.go

pkg/minikube/bootstrapper/kubeadm/kubeadm.go

@@ -698,6 +698,7 @@ func generateConfig(k8s config.KubernetesConfig, r cruntime.Manager) ([]byte, er
 		KubernetesVersion string
 		EtcdDataDir       string
 		NodeName          string
+		DNSDomain         string
 		CRISocket         string
 		ImageRepository   string
 		ExtraArgs         []ComponentExtraArgs
@@ -717,6 +718,7 @@ func generateConfig(k8s config.KubernetesConfig, r cruntime.Manager) ([]byte, er
 		ExtraArgs:         extraComponentConfig,
 		FeatureArgs:       kubeadmFeatureArgs,
 		NoTaintMaster:     false, // That does not work with k8s 1.12+
+		DNSDomain:         k8s.DNSDomain,
 	}
 
 	if k8s.ServiceCIDR != "" {

pkg/minikube/bootstrapper/kubeadm/kubeadm_test.go

@@ -235,6 +235,67 @@ func recentReleases() ([]string, error) {
 	return versions, nil
 }
 
+/**
+Need a separate test function to test the DNS server IP
+as v1.11 yaml file is very different compared to v1.12+.
+This test case has only 1 thing to test and that is the
+nnetworking/dnsDomain value
+*/
+func TestGenerateConfigDNS(t *testing.T) {
+	versions := []string{"v1.16", "v1.15", "v1.14", "v1.13", "v1.12"}
+	tests := []struct {
+		name      string
+		runtime   string
+		shouldErr bool
+		cfg       config.KubernetesConfig
+	}{
+		{"dns", "docker", false, config.KubernetesConfig{DNSDomain: "1.1.1.1"}},
+	}
+	for _, version := range versions {
+		for _, tc := range tests {
+			runtime, err := cruntime.New(cruntime.Config{Type: tc.runtime})
+			if err != nil {
+				t.Fatalf("runtime: %v", err)
+			}
+			tname := tc.name + "_" + version
+			t.Run(tname, func(t *testing.T) {
+				cfg := tc.cfg
+				cfg.NodeIP = "1.1.1.1"
+				cfg.NodeName = "mk"
+				cfg.KubernetesVersion = version + ".0"
+
+				got, err := generateConfig(cfg, runtime)
+				if err != nil && !tc.shouldErr {
+					t.Fatalf("got unexpected error generating config: %v", err)
+				}
+				if err == nil && tc.shouldErr {
+					t.Fatalf("expected error but got none, config: %s", got)
+				}
+				if tc.shouldErr {
+					return
+				}
+				expected, err := ioutil.ReadFile(fmt.Sprintf("testdata/%s/%s.yaml", version, tc.name))
+				if err != nil {
+					t.Fatalf("unable to read testdata: %v", err)
+				}
+				diff, err := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{
+					A:        difflib.SplitLines(string(expected)),
+					B:        difflib.SplitLines(string(got)),
+					FromFile: "Expected",
+					ToFile:   "Got",
+					Context:  1,
+				})
+				if err != nil {
+					t.Fatalf("diff error: %v", err)
+				}
+				if diff != "" {
+					t.Errorf("unexpected diff:\n%s\n===== [RAW OUTPUT] =====\n%s", diff, got)
+				}
+			})
+		}
+	}
+}
+
 func TestGenerateConfig(t *testing.T) {
 	extraOpts := getExtraOpts()
 	extraOptsPodCidr := getExtraOptsPodCidr()

pkg/minikube/bootstrapper/kubeadm/templates.go

@@ -84,7 +84,7 @@ etcd:
     dataDir: {{.EtcdDataDir}}
 kubernetesVersion: {{.KubernetesVersion}}
 networking:
-  dnsDomain: cluster.local
+  dnsDomain: {{if .DNSDomain}}{{.DNSDomain}}{{else}}cluster.local{{end}}
   podSubnet: {{if .PodSubnet}}{{.PodSubnet}}{{else}}""{{end}}
   serviceSubnet: {{.ServiceCIDR}}
 ---
@@ -138,7 +138,7 @@ etcd:
     dataDir: {{.EtcdDataDir}}
 kubernetesVersion: {{.KubernetesVersion}}
 networking:
-  dnsDomain: cluster.local
+  dnsDomain: {{if .DNSDomain}}{{.DNSDomain}}{{else}}cluster.local{{end}}
   podSubnet: ""
   serviceSubnet: {{.ServiceCIDR}}
 ---

pkg/minikube/bootstrapper/kubeadm/testdata/v1.12/dns.yaml

@@ -0,0 +1,39 @@
+apiVersion: kubeadm.k8s.io/v1alpha3
+kind: InitConfiguration
+apiEndpoint:
+  advertiseAddress: 1.1.1.1
+  bindPort: 8443
+bootstrapTokens:
+  - groups:
+      - system:bootstrappers:kubeadm:default-node-token
+    ttl: 24h0m0s
+    usages:
+      - signing
+      - authentication
+nodeRegistration:
+  criSocket: /var/run/dockershim.sock
+  name: mk
+  taints: []
+---
+apiVersion: kubeadm.k8s.io/v1alpha3
+kind: ClusterConfiguration
+apiServerExtraArgs:
+  enable-admission-plugins: "Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota"
+certificatesDir: /var/lib/minikube/certs
+clusterName: kubernetes
+controlPlaneEndpoint: localhost:8443
+etcd:
+  local:
+    dataDir: /var/lib/minikube/etcd
+kubernetesVersion: v1.12.0
+networking:
+  dnsDomain: 1.1.1.1
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+apiVersion: kubelet.config.k8s.io/v1beta1
+kind: KubeletConfiguration
+evictionHard:
+  nodefs.available: "0%"
+  nodefs.inodesFree: "0%"
+  imagefs.available: "0%"

pkg/minikube/bootstrapper/kubeadm/testdata/v1.13/dns.yaml

@@ -0,0 +1,39 @@
+apiVersion: kubeadm.k8s.io/v1alpha3
+kind: InitConfiguration
+apiEndpoint:
+  advertiseAddress: 1.1.1.1
+  bindPort: 8443
+bootstrapTokens:
+  - groups:
+      - system:bootstrappers:kubeadm:default-node-token
+    ttl: 24h0m0s
+    usages:
+      - signing
+      - authentication
+nodeRegistration:
+  criSocket: /var/run/dockershim.sock
+  name: mk
+  taints: []
+---
+apiVersion: kubeadm.k8s.io/v1alpha3
+kind: ClusterConfiguration
+apiServerExtraArgs:
+  enable-admission-plugins: "Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota"
+certificatesDir: /var/lib/minikube/certs
+clusterName: kubernetes
+controlPlaneEndpoint: localhost:8443
+etcd:
+  local:
+    dataDir: /var/lib/minikube/etcd
+kubernetesVersion: v1.13.0
+networking:
+  dnsDomain: 1.1.1.1
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+apiVersion: kubelet.config.k8s.io/v1beta1
+kind: KubeletConfiguration
+evictionHard:
+  nodefs.available: "0%"
+  nodefs.inodesFree: "0%"
+  imagefs.available: "0%"

pkg/minikube/bootstrapper/kubeadm/testdata/v1.14/dns.yaml

@@ -0,0 +1,43 @@
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: InitConfiguration
+localAPIEndpoint:
+  advertiseAddress: 1.1.1.1
+  bindPort: 8443
+bootstrapTokens:
+  - groups:
+      - system:bootstrappers:kubeadm:default-node-token
+    ttl: 24h0m0s
+    usages:
+      - signing
+      - authentication
+nodeRegistration:
+  criSocket: /var/run/dockershim.sock
+  name: mk
+  taints: []
+---
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: ClusterConfiguration
+apiServer:
+  extraArgs:
+    enable-admission-plugins: "NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota"
+certificatesDir: /var/lib/minikube/certs
+clusterName: kubernetes
+controlPlaneEndpoint: localhost:8443
+dns:
+  type: CoreDNS
+etcd:
+  local:
+    dataDir: /var/lib/minikube/etcd
+kubernetesVersion: v1.14.0
+networking:
+  dnsDomain: 1.1.1.1
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+apiVersion: kubelet.config.k8s.io/v1beta1
+kind: KubeletConfiguration
+imageGCHighThresholdPercent: 100
+evictionHard:
+  nodefs.available: "0%"
+  nodefs.inodesFree: "0%"
+  imagefs.available: "0%"

pkg/minikube/bootstrapper/kubeadm/testdata/v1.15/dns.yaml

@@ -0,0 +1,43 @@
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: InitConfiguration
+localAPIEndpoint:
+  advertiseAddress: 1.1.1.1
+  bindPort: 8443
+bootstrapTokens:
+  - groups:
+      - system:bootstrappers:kubeadm:default-node-token
+    ttl: 24h0m0s
+    usages:
+      - signing
+      - authentication
+nodeRegistration:
+  criSocket: /var/run/dockershim.sock
+  name: mk
+  taints: []
+---
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: ClusterConfiguration
+apiServer:
+  extraArgs:
+    enable-admission-plugins: "NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota"
+certificatesDir: /var/lib/minikube/certs
+clusterName: kubernetes
+controlPlaneEndpoint: localhost:8443
+dns:
+  type: CoreDNS
+etcd:
+  local:
+    dataDir: /var/lib/minikube/etcd
+kubernetesVersion: v1.15.0
+networking:
+  dnsDomain: 1.1.1.1
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+apiVersion: kubelet.config.k8s.io/v1beta1
+kind: KubeletConfiguration
+imageGCHighThresholdPercent: 100
+evictionHard:
+  nodefs.available: "0%"
+  nodefs.inodesFree: "0%"
+  imagefs.available: "0%"

pkg/minikube/bootstrapper/kubeadm/testdata/v1.16/dns.yaml

@@ -0,0 +1,43 @@
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: InitConfiguration
+localAPIEndpoint:
+  advertiseAddress: 1.1.1.1
+  bindPort: 8443
+bootstrapTokens:
+  - groups:
+      - system:bootstrappers:kubeadm:default-node-token
+    ttl: 24h0m0s
+    usages:
+      - signing
+      - authentication
+nodeRegistration:
+  criSocket: /var/run/dockershim.sock
+  name: mk
+  taints: []
+---
+apiVersion: kubeadm.k8s.io/v1beta1
+kind: ClusterConfiguration
+apiServer:
+  extraArgs:
+    enable-admission-plugins: "NamespaceLifecycle,LimitRanger,ServiceAccount,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,MutatingAdmissionWebhook,ValidatingAdmissionWebhook,ResourceQuota"
+certificatesDir: /var/lib/minikube/certs
+clusterName: kubernetes
+controlPlaneEndpoint: localhost:8443
+dns:
+  type: CoreDNS
+etcd:
+  local:
+    dataDir: /var/lib/minikube/etcd
+kubernetesVersion: v1.16.0
+networking:
+  dnsDomain: 1.1.1.1
+  podSubnet: ""
+  serviceSubnet: 10.96.0.0/12
+---
+apiVersion: kubelet.config.k8s.io/v1beta1
+kind: KubeletConfiguration
+imageGCHighThresholdPercent: 100
+evictionHard:
+  nodefs.available: "0%"
+  nodefs.inodesFree: "0%"
+  imagefs.available: "0%"