kubeadm: rename the kube-dns phases addon

The command `kubeadm alpha phases addon` has a property
called `kube-dns` which would install kube-dns, pre 1.11.

In the case of 1.11 this property will install CoreDNS,
because the property is also bound to the `CoreDNS` feature gate,
which is now `true` by default.

Fix that by renaming the property to `coredns`, updating the Cobra
info and also updating the unit tests.

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

@@ -39,24 +39,24 @@ import (
 
 var (
 	allAddonsLongDesc = normalizer.LongDesc(`
-		Installs the kube-dns and the kube-proxys addons components via the API server.  
+		Installs the CoreDNS and the kube-proxys addons components via the API server.
 		Please note that although the DNS server is deployed, it will not be scheduled until CNI is installed.
 		` + cmdutil.AlphaDisclaimer)
 
 	allAddonsExample = normalizer.Examples(`
-		# Installs the kube-dns and the kube-proxys addons components via the API server, 
+		# Installs the CoreDNS and the kube-proxys addons components via the API server,
 		# functionally equivalent to what installed by kubeadm init. 
 
 		kubeadm alpha phase selfhosting from-staticpods
 		`)
 
-	kubednsAddonsLongDesc = normalizer.LongDesc(`
+	corednsAddonsLongDesc = normalizer.LongDesc(`
-		Installs the kube-dns addon components via the API server.  
+		Installs the CoreDNS addon components via the API server.
 		Please note that although the DNS server is deployed, it will not be scheduled until CNI is installed.
 		` + cmdutil.AlphaDisclaimer)
 
 	kubeproxyAddonsLongDesc = normalizer.LongDesc(`
-		Installs the kube-proxy addon components via the API server.  
+		Installs the kube-proxy addon components via the API server.
 		` + cmdutil.AlphaDisclaimer)
 )
 
@@ -116,9 +116,9 @@ func getAddonsSubCommands() []*cobra.Command {
 			cmdFunc:  EnsureAllAddons,
 		},
 		{
-			use:     "kube-dns",
+			use:     "coredns",
-			short:   "Installs the kube-dns addon to a Kubernetes cluster",
+			short:   "Installs the CoreDNS addon to a Kubernetes cluster",
-			long:    kubednsAddonsLongDesc,
+			long:    corednsAddonsLongDesc,
 			cmdFunc: dnsaddon.EnsureDNSAddon,
 		},
 		{
@@ -151,7 +151,7 @@ func getAddonsSubCommands() []*cobra.Command {
 			cmd.Flags().StringVar(&cfg.Networking.PodSubnet, "pod-network-cidr", cfg.Networking.PodSubnet, `The range of IP addresses used for the Pod network`)
 		}
 
-		if properties.use == "all" || properties.use == "kube-dns" {
+		if properties.use == "all" || properties.use == "coredns" {
 			cmd.Flags().StringVar(&cfg.Networking.DNSDomain, "service-dns-domain", cfg.Networking.DNSDomain, `Alternative domain for services`)
 			cmd.Flags().StringVar(&cfg.Networking.ServiceSubnet, "service-cidr", cfg.Networking.ServiceSubnet, `The range of IP address used for service VIPs`)
 			cmd.Flags().StringVar(&featureGatesString, "feature-gates", featureGatesString, "A set of key=value pairs that describe feature gates for various features."+

cmd/kubeadm/app/cmd/phases/addons_test.go

@@ -56,7 +56,7 @@ func TestAddonsSubCommandsHasFlags(t *testing.T) {
 			},
 		},
 		{
-			command: "kube-dns",
+			command: "coredns",
 			additionalFlags: []string{
 				"service-dns-domain",
 				"service-cidr",

docs/.generated_docs

@@ -9,7 +9,7 @@ docs/admin/kubeadm_alpha.md
 docs/admin/kubeadm_alpha_phase.md
 docs/admin/kubeadm_alpha_phase_addon.md
 docs/admin/kubeadm_alpha_phase_addon_all.md
-docs/admin/kubeadm_alpha_phase_addon_kube-dns.md
+docs/admin/kubeadm_alpha_phase_addon_coredns.md
 docs/admin/kubeadm_alpha_phase_addon_kube-proxy.md
 docs/admin/kubeadm_alpha_phase_bootstrap-token.md
 docs/admin/kubeadm_alpha_phase_bootstrap-token_all.md
@@ -86,7 +86,7 @@ docs/man/man1/kube-controller-manager.1
 docs/man/man1/kube-proxy.1
 docs/man/man1/kube-scheduler.1
 docs/man/man1/kubeadm-alpha-phase-addon-all.1
-docs/man/man1/kubeadm-alpha-phase-addon-kube-dns.1
+docs/man/man1/kubeadm-alpha-phase-addon-coredns.1
 docs/man/man1/kubeadm-alpha-phase-addon-kube-proxy.1
 docs/man/man1/kubeadm-alpha-phase-addon.1
 docs/man/man1/kubeadm-alpha-phase-bootstrap-token-all.1