def METHOD_NAME(argv):
    # Load label file
    try:
        new_lables = json.load(open(argv[1]))
    except IndexError:
        print("%s <lables.json> required!" %  __file__, file=sys.stderr)
        sys.exit(1)
    except ValueError as err:
        print("%s invalid json: %s" % (sys.argv[1], err), file=sys.stderr)
        sys.exit(1)
    # Pull defaults from metadata
    metadata = get_metadata()
    project, zone = itemgetter(1, 3)(metadata['zone'].split("/"))
    instance_name = metadata['name']
    # Google Creds
    creds = GoogleCredentials.get_application_default()
    # Describe Instance
    conn = discovery.build('compute', 'beta', credentials=creds)
    instance = conn.instances().get(project=project, zone=zone,
                                    instance=instance_name).execute()
    # Label Instance
    label(instance['selfLink'], creds.get_access_token().access_token,
          label_merge(instance['labels'] if 'labels' in instance else {},
                      instance["labelFingerprint"], new_lables))
    # Label Disks
    for i in instance['disks']:
        # Skip local disk
        if 'source' not in i:
            continue
        disk = conn.disks().get(project=project, zone=zone,
                                disk=i['source'].split('/')[-1]).execute()
        label(disk['selfLink'], creds.get_access_token().access_token,
              label_merge(disk['labels'] if 'labels' in disk else {},
                          disk["labelFingerprint"], new_lables))