{Compute} az vmss: Support Open Capacity Reservation

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_basic.yaml

@@ -673,7 +673,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_fixed.yaml

@@ -655,7 +655,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.60.0 azsdk-python-core/1.30.1 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_fixed000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_fixed000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_fixed000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_predictive_policy.yaml

@@ -627,7 +627,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_predictive_policy000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_predictive_policy000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_predictive_policy000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_recurring.yaml

@@ -627,7 +627,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_recurring000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_recurring000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_recurring000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_refined.yaml

@@ -627,7 +627,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_refine000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_refine000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_refine000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_rule_with_dimensions.yaml

@@ -627,7 +627,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_rule_with_dimensions000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_rule_with_dimensions000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_rule_with_dimensions000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_rules.yaml

@@ -627,7 +627,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_rules000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_rules000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_rules000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/monitor/tests/latest/recordings/test_monitor_autoscale_show_predictive_metric.yaml

@@ -627,7 +627,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.63.0 azsdk-python-core/1.28.0 Python/3.10.11 (Windows-10-10.0.22631-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_show_predictive_metric000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_show_predictive_metric000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmss1\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_monitor_autoscale_show_predictive_metric000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmss1\"\

src/azure-cli/azure/cli/command_modules/network/tests/latest/recordings/test_network_watcher_packet_capture_vmss_as_target.yaml

@@ -722,7 +722,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.86.0 azsdk-python-core/1.39.0 Python/3.12.10 (Windows-11-10.0.26200-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmssForPcap\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap\",\r\n
@@ -6118,7 +6118,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.86.0 azsdk-python-core/1.39.0 Python/3.12.10 (Windows-11-10.0.26200-SP0)
     method: PUT
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmssForPcap\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap\",\r\n
@@ -6322,7 +6322,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.86.0 azsdk-python-core/1.39.0 Python/3.12.10 (Windows-11-10.0.26200-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmssForPcap\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap\",\r\n
@@ -6409,7 +6409,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.86.0 azsdk-python-core/1.39.0 Python/3.12.10 (Windows-11-10.0.26200-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmssForPcap\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap\",\r\n
@@ -6718,7 +6718,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.86.0 azsdk-python-core/1.39.0 Python/3.12.10 (Windows-11-10.0.26200-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmssForPcap\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap\",\r\n
@@ -7028,7 +7028,7 @@ interactions:
       User-Agent:
       - AZURECLI/2.86.0 azsdk-python-core/1.39.0 Python/3.12.10 (Windows-11-10.0.26200-SP0)
     method: GET
-    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2025-11-01
+    uri: https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap?api-version=2026-04-01
   response:
     body:
       string: "{\r\n  \"name\": \"vmssForPcap\",\r\n  \"id\": \"/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/cli_test_nw_packet_capture_vmss_as_target000001/providers/Microsoft.Compute/virtualMachineScaleSets/vmssForPcap\",\r\n

src/azure-cli/azure/cli/command_modules/vm/_help.py

@@ -2306,6 +2306,9 @@
   - name: Create a VMSS from community gallery image.
     text: >
         az vmss create -n MyVmss -g MyResourceGroup --image /CommunityGalleries/{gallery_unique_name}/Images/{image}/Versions/{version}
+  - name: Create a VMSS that is not associated with any capacity reservation.
+    text: >
+        az vmss create -n MyVmss -g MyResourceGroup --image Ubuntu2204 --disable-capacity-reservation-assignment true
   - name: Create a Windows VMSS with patch mode 'Manual' (Currently patch mode 'AutomaticByPlatform' is not supported during VMSS creation as health extension which is required for 'AutomaticByPlatform' mode cannot be set during VMSS creation).
     text: >
         az vmss create -n MyVmss -g MyResourceGroup --image Win2019Datacenter --enable-agent --enable-auto-update false --patch-mode Manual --orchestration-mode Flexible
@@ -2859,6 +2862,8 @@
     text: >
         az vmss update -n MyVmss -g MyResourceGroup --security-posture-reference-id /CommunityGalleries/{communityGalleryName}/securityPostures/{securityPostureName}/versions/{version} \\
             --security-posture-reference-exclude-extensions "c:\\tmp\\exclude_extensions.json"
+  - name: Opt out a VMSS from being associated with any capacity reservation.
+    text: az vmss update -n MyVmss -g MyResourceGroup --disable-capacity-reservation-assignment true
 """
 
 helps['vmss update-instances'] = """

src/azure-cli/azure/cli/command_modules/vm/_params.py

@@ -989,6 +989,9 @@ def load_arguments(self, _):
             c.argument('enable_automatic_zone_balancing', arg_type=get_three_state_flag(), options_list=['--enable-automatic-zone-balancing', '--enable-zone-balancing'], help='Specify whether automatic AZ balancing should be enabled on the virtualmachine scale set.')
             c.argument('automatic_zone_balancing_strategy', arg_type=get_enum_type(AutomaticZoneBalancingStrategy), options_list=['--automatic-zone-balancing-strategy', '--balancing-strategy'], help='Type of rebalance strategy that will be used for rebalancing virtualmachines in the scale set across availability zones.')
             c.argument('automatic_zone_balancing_behavior', arg_type=get_enum_type(AutomaticZoneBalancingBehavior), options_list=['--automatic-zone-balancing-behavior', '--balancing-behavior'], help='Type of rebalance behavior that will be used for recreating virtualmachines in the scale set across availability zones.')
+            c.argument('disable_capacity_reservation_assignment', arg_type=get_three_state_flag(),
+                       options_list=['--disable-capacity-reservation-assignment', '--no-cap-reservation'],
+                       help='Specifies whether the virtual machine scale set is explicitly opted out from being associated with any capacity reservation. When set to true, its virtual machines will not be allowed to implicitly or explicitly associate with any type of capacity reservation and will consume publicly available capacity. This option applies to the parent VMSS only.')
 
     with self.argument_context('vmss update') as c:
         c.argument('instance_id', id_part='child_name_1', help="Update the VM instance with this ID. If missing, update the VMSS.")

src/azure-cli/azure/cli/command_modules/vm/_template_builder.py

@@ -1061,6 +1061,7 @@ def build_vmss_resource(cmd, name, computer_name_prefix, location, tags, overpro
                         enable_cross_zone_upgrade=None, prioritize_unhealthy_instances=None, edge_zone=None,
                         orchestration_mode=None, user_data=None, network_api_version=None,
                         enable_spot_restore=None, spot_restore_timeout=None, capacity_reservation_group=None,
+                        disable_capacity_reservation_assignment=None,
                         enable_auto_update=None, patch_mode=None, enable_agent=None, security_type=None,
                         enable_secure_boot=None, enable_vtpm=None, automatic_repairs_action=None, v_cpus_available=None,
                         v_cpus_per_core=None, os_disk_security_encryption_type=None,
@@ -1679,12 +1680,15 @@ def build_vmss_resource(cmd, name, computer_name_prefix, location, tags, overpro
     if network_profile:
         virtual_machine_profile['networkProfile'] = network_profile
 
-    if capacity_reservation_group:
-        virtual_machine_profile['capacityReservation'] = {
-            'capacityReservationGroup': {
+    if capacity_reservation_group or disable_capacity_reservation_assignment is not None:
+        virtual_machine_profile['capacityReservation'] = {}
+        if capacity_reservation_group:
+            virtual_machine_profile['capacityReservation']['capacityReservationGroup'] = {
                 'id': capacity_reservation_group
             }
-        }
+        if disable_capacity_reservation_assignment is not None:
+            virtual_machine_profile['capacityReservation']['disableCapacityReservationAssignment'] = \
+                disable_capacity_reservation_assignment
 
     if security_posture_reference_id:
         virtual_machine_profile['securityPostureReference'] = {
@@ -1741,7 +1745,7 @@ def build_vmss_resource(cmd, name, computer_name_prefix, location, tags, overpro
         'name': name,
         'location': location,
         'tags': tags,
-        'apiVersion': '2025-11-01',
+        'apiVersion': '2026-04-01',
         'dependsOn': [],
         'properties': vmss_properties
     }

src/azure-cli/azure/cli/command_modules/vm/_validators.py

@@ -1951,6 +1951,10 @@ def process_vmss_create_namespace(cmd, namespace):
 
 
 def validate_vmss_update_namespace(cmd, namespace):  # pylint: disable=unused-argument
+    if namespace.instance_id and namespace.disable_capacity_reservation_assignment is not None:
+        raise MutuallyExclusiveArgumentError(
+            "--disable-capacity-reservation-assignment applies to the parent VMSS and cannot be used with "
+            "--instance-id")
     if not namespace.instance_id:
         if namespace.protect_from_scale_in is not None or namespace.protect_from_scale_set_actions is not None:
             raise CLIError("usage error: protection policies can only be applied to VM instances within a VMSS."
@@ -2827,6 +2831,11 @@ def validate_edge_zone(cmd, namespace):  # pylint: disable=unused-argument
 
 
 def _validate_capacity_reservation_group(cmd, namespace):
+    if getattr(namespace, 'capacity_reservation_group', None) is not None and \
+            getattr(namespace, 'disable_capacity_reservation_assignment', None) is not None:
+        raise MutuallyExclusiveArgumentError(
+            "You can only specify one of --capacity-reservation-group and "
+            "--disable-capacity-reservation-assignment")
 
     if namespace.capacity_reservation_group and namespace.capacity_reservation_group != 'None':