Address comments

sky/provision/azure/instance.py

@@ -1,6 +1,7 @@
 """Azure instance provisioning."""
 import logging
 from multiprocessing import pool
+import typing
 from typing import Any, Callable, Dict, List, Optional
 
 from sky import exceptions
@@ -10,6 +11,9 @@
 from sky.utils import common_utils
 from sky.utils import ux_utils
 
+if typing.TYPE_CHECKING:
+    from azure.mgmt import compute as azure_compute
+
 logger = sky_logging.init_logger(__name__)
 
 # Suppress noisy logs from Azure SDK. Reference:
@@ -21,6 +25,8 @@
 TAG_RAY_CLUSTER_NAME = 'ray-cluster-name'
 TAG_RAY_NODE_KIND = 'ray-node-type'
 
+_RESOURCE_GROUP_NOT_FOUND_ERROR_MESSAGE = 'ResourceGroupNotFound'
+
 
 def get_azure_sdk_function(client: Any, function_name: str) -> Callable:
     """Retrieve a callable function from Azure SDK client object.
@@ -99,7 +105,8 @@ def cleanup_ports(
     del cluster_name_on_cloud, ports, provider_config  # Unused.
 
 
-def _get_vm_status(compute_client, vm_name: str, resource_group: str) -> str:
+def _get_vm_status(compute_client: 'azure_compute.ComputeManagementClient',
+                   vm_name: str, resource_group: str) -> str:
     instance = compute_client.virtual_machines.instance_view(
         resource_group_name=resource_group, vm_name=vm_name).as_dict()
     for status in instance['statuses']:
@@ -115,8 +122,9 @@ def _get_vm_status(compute_client, vm_name: str, resource_group: str) -> str:
     raise ValueError(f'Failed to get status for VM {vm_name}')
 
 
-def _filter_instances(compute_client, filters: Dict[str, str],
-                      resource_group: str) -> List[Any]:
+def _filter_instances(compute_client: 'azure_compute.ComputeManagementClient',
+                      filters: Dict[str,
+                                    str], resource_group: str) -> List[Any]:
 
     def match_tags(vm):
         for k, v in filters.items():
@@ -130,7 +138,7 @@ def match_tags(vm):
         vms = list_virtual_machines(resource_group_name=resource_group)
         nodes = list(filter(match_tags, vms))
     except azure.exceptions().ResourceNotFoundError as e:
-        if 'ResourceGroupNotFound' in str(e):
+        if _RESOURCE_GROUP_NOT_FOUND_ERROR_MESSAGE in str(e):
             return []
         raise
     return nodes
@@ -163,7 +171,8 @@ def query_instances(
         'Migrating': status_lib.ClusterStatus.INIT,
         'Deleting': None,
         # Succeeded in provisioning state means the VM is provisioned but not
-        # necessarily running.
+        # necessarily running. We exclude Succeeded state here, and the caller
+        # should determine the status of the VM based on the power state.
         # 'Succeeded': status_lib.ClusterStatus.UP,
     }