docs: def main():
      '''Main routine.'''
  
      # process arguments
      if len(sys.argv) < 3:
          usage()
  
      rgname = sys.argv[1]
      vmss = sys.argv[2]
  
      # Load Azure app defaults
      try:
          with open('azurermconfig.json') as config_file:
              config_data = json.load(config_file)
      except FileNotFoundError:
          sys.exit("Error: Expecting azurermconfig.json in current folder")
  
      tenant_id = config_data['tenantId']
      app_id = config_data['appId']
      app_secret = config_data['appSecret']
      sub_id = config_data['subscriptionId']
  
      access_token = azurerm.get_access_token(tenant_id, app_id, app_secret)
  
      # get metric definitions
      provider = 'Microsoft.Compute'
      resource_type = 'virtualMachineScaleSets'
  
      metric_definitions = azurerm.list_metric_defs_for_resource(access_token, sub_id, rgname,
                                                                 provider, resource_type, vmss)
  
      print(json.dumps(metric_definitions, sort_keys=False, indent=2, separators=(',', ': ')))
  
      metrics = azurerm.get_metrics_for_resource(access_token, sub_id, rgname,
                                                 provider, resource_type, vmss)
  
      print(json.dumps(metrics, sort_keys=False, indent=2, separators=(',', ': ')))