code: def get_vm_ids_by_ud(access_token, subscription_id, resource_group, vmssname, updatedomain):
      '''look at VMSS VM instance view to get VM IDs by UD'''
      instance_viewlist = azurerm.list_vmss_vm_instance_view(access_token, subscription_id,
                                                             resource_group, vmssname)
      # print(json.dumps(instance_viewlist, sort_keys=False, indent=2, separators=(',', ': ')))
  
      # loop through the instance view list, and build the vm id list of VMs in
      # the matching UD
      udinstancelist = []
      for instance_view in instance_viewlist['value']:
          vmud = instance_view['properties']['instance_view']['platformUpdateDomain']
          if vmud == updatedomain:
              udinstancelist.append(instance_view['instanceId'])
      udinstancelist.sort()
      return udinstancelisf get_vm_ids_by_ud(access_token, subscription_id, resource_group, vmssname, updatedomain):
      '''look at VMSS VM instance view to get VM IDs by UD'''
      instance_viewlist = azurerm.list_vmss_vm_instance_view(access_token, subscription_id,
                                                             resource_group, vmssname)
      # print(json.dumps(instance_viewlist, sort_keys=False, indent=2, separators=(',', ': ')))
  
      # loop through the instance view list, and build the vm id list of VMs in
      # the matching UD
      udinstancelist = []
      for instance_view in instance_viewlist['value']:
          vmud = instance_view['properties']['instance_view']['platformUpdateDomain']
          if vmud == updatedomain:
              udinstancelist.append(instance_view['instanceId'])
      udinstancelist.sort()
      return udinstancelist
docs: look at VMSS VM instance view to get VM IDs by UD