kubelet —cluster-domain is user-overridable (Azure#2276)

docs/clusterdefinition.md

@@ -161,6 +161,7 @@ Below is a list of kubelet options that acs-engine will configure by default:
 |---|---|
 |"--cloud-config"|"/etc/kubernetes/azure.json"|
 |"--cloud-provider"|"azure"|
+|"--cluster-domain"|"cluster.local"|
 |"--pod-infra-container-image"|"pause-amd64:<version>"|
 |"--max-pods"|"110"|
 |"--eviction-hard"|"memory.available<100Mi,nodefs.available<10%,nodefs.inodesFree<5%"|
@@ -178,7 +179,6 @@ Below is a list of kubelet options that are *not* currently user-configurable, e
 |"--azure-container-registry-config"|"/etc/kubernetes/azure.json"|
 |"--allow-privileged"|"true"|
 |"--pod-manifest-path"|"/etc/kubernetes/manifests"|
-|"--cluster-domain"|"cluster.local"|
 |"--network-plugin"|"cni"|
 |"--node-labels"|(based on Azure node metadata)|
 |"--cgroups-per-qos"|"false"|

pkg/acsengine/defaults-kubelet.go

@@ -17,7 +17,6 @@ func setKubeletConfig(cs *api.ContainerService) {
 		"--authorization-mode":              "Webhook",
 		"--client-ca-file":                  "/etc/kubernetes/certs/ca.crt",
 		"--pod-manifest-path":               "/etc/kubernetes/manifests",
-		"--cluster-domain":                  "cluster.local",
 		"--cluster-dns":                     o.KubernetesConfig.DNSServiceIP,
 		"--cgroups-per-qos":                 "false",
 		"--enforce-node-allocatable":        "",
@@ -33,6 +32,7 @@ func setKubeletConfig(cs *api.ContainerService) {
 
 	// Default Kubelet config
 	defaultKubeletConfig := map[string]string{
+		"--cluster-domain":               "cluster.local",
 		"--network-plugin":               "cni",
 		"--pod-infra-container-image":    cloudSpecConfig.KubernetesSpecConfig.KubernetesImageBase + KubeConfigs[o.OrchestratorVersion]["pause"],
 		"--max-pods":                     strconv.Itoa(DefaultKubernetesKubeletMaxPods),