respond to davidopp's feedback

cluster/azure/config-default.sh

@@ -14,18 +14,32 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# cp config-default.sh config-real.sh
-# export KUBE_CONFIG_FILE=`pwd`/config-real.sh
-
-AZURE_LOCATION="westus" # this must be in the FQDN format so that url construction works in util.sh
-AZURE_DEPLOY_ID="" # this will be autogenerated using the current date/time if left blank
-AZURE_MASTER_SIZE="Standard_A1"
-AZURE_MINION_SIZE="Standard_A1"
-AZURE_USERNAME="kube"
-NUM_NODES=3
-
-#AZURE_TENANT_ID=""
-#AZURE_SUBSCRIPTION_ID=""
-#AZURE_AUTH_METHOD="client_secret"
-#AZURE_CLIENT_ID=""
-#AZURE_CLIENT_SECRET=""
+# Azure location to deploy to. (Storage account, resource group, resources)
+# Must be be specified in the compact form. ("westus" is ok, "West US" is not)
+AZURE_LOCATION="${AZURE_LOCATION:-"westus"}"
+
+# An identifier for the deployment. It can be left blank and an identifier
+# will be generated from the date/time.
+AZURE_DEPLOY_ID="${AZURE_DEPLOY_ID:-"kube-$(date +"%Y%m%d-%H%M%S")"}"
+
+AZURE_MASTER_SIZE="${AZURE_MASTER_SIZE:-"Standard_A1"}"
+AZURE_NODE_SIZE="${AZURE_NODE_SIZE:-"Standard_A1"}"
+
+# Username of the admin account created on the VMs
+AZURE_USERNAME="${AZURE_USERNAME:-"kube"}"
+
+# Initial number of worker nodes to provision
+NUM_NODES=${NUM_NODES:-3}
+
+# The Azure Active Directoy (AAD) TenantID to which the subscription belongs.
+# This should be a GUID.
+AZURE_TENANT_ID="${AZURE_TENANT_ID:-}"
+
+# The target Azure subscription ID
+# This should be a GUID.
+AZURE_SUBSCRIPTION_ID="${AZURE_SUBSCRIPTION_ID:-}"
+
+# The authentication mechanism to use. The default "device" is recommended as
+# it requires the least ahead-of-time setup.
+# This should be one of: { "device", "client_secret" }
+AZURE_AUTH_METHOD="${AZURE_AUTH_METHOD:-"device"}"