az: use resource_group_name for vnet if vnet_resource_group_name unset

python/az/aro/azext_aro/_params.py

@@ -3,6 +3,7 @@ from azext_aro._validators import validate_client_id
 from azext_aro._validators import validate_client_secret
 from azext_aro._validators import validate_subnet
 from azext_aro._validators import validate_vnet
+from azext_aro._validators import validate_vnet_resource_group_name
 from azext_aro._validators import validate_worker_count
 from azext_aro._validators import validate_worker_vm_disk_size_gb
 from azure.cli.core.commands.parameters import name_type
@@ -50,7 +51,8 @@ def load_arguments(self, _):
         c.argument('vnet_resource_group_name',
                    resource_group_name_type,
                    options_list=['--vnet-resource-group'],
-                   help='Name of vnet resource group.')
+                   help='Name of vnet resource group.',
+                   validator=validate_vnet_resource_group_name)
         c.argument('vnet',
                    help='Name or ID of vnet.  If name is supplied, `--vnet-resource-group` must be supplied.',
                    validator=validate_vnet)

python/az/aro/azext_aro/_validators.py

@@ -127,12 +127,10 @@ def validate_subnets(master_subnet, worker_subnet):
 
 
 def validate_vnet(cmd, namespace):
+    validate_vnet_resource_group_name(namespace)
+
     if namespace.vnet:
         if not is_valid_resource_id(namespace.vnet):
-            if not namespace.vnet_resource_group_name:
-                raise CLIError(
-                    "Must specify --vnet-resource-group-name if --vnet is not an id.")
-
             namespace.vnet = resource_id(
                 subscription=get_subscription_id(cmd.cli_ctx),
                 resource_group=namespace.vnet_resource_group_name,
@@ -142,6 +140,11 @@ def validate_vnet(cmd, namespace):
             )
 
 
+def validate_vnet_resource_group_name(namespace):
+    if not namespace.vnet_resource_group_name:
+        namespace.vnet_resource_group_name = namespace.validate_vnet_resource_group_name
+
+
 def validate_worker_count(namespace):
     if namespace.worker_count:
         namespace.worker_count = _validate_int(