status: 500 reason: Internal Server Error OVIRT PYTHON SDK 3.3

ovirt33.conf

# ovirt33.conf
[oVirt]
url: https://xxxxx
username: admin@internal
password: secret
insecure: 1
dc_name: local_datacenter
cluster_name: local_cluster
storage_name: local_storage
export_name: exports
template_name: tpl-small-vm

test-api.py

__author__ = 'hleclerc@cloud.alterway.fr'
from twisted.internet import task
from twisted.internet import reactor
from ovirtsdk.api import API
from ovirtsdk.infrastructure.errors import RequestError, ConnectionError
from ovirtsdk.xml import params
import time
import ConfigParser
import sys


VERSION = params.Version(major='3', minor='3')

config = ConfigParser.ConfigParser()
config.read('ovirt33.conf')
url = config.get('oVirt', 'url')
username = config.get('oVirt', 'username')
password = config.get('oVirt', 'password')
insecure = config.getint('oVirt', 'insecure')

DC_NAME = config.get('oVirt','dc_name')
CLUSTER_NAME = config.get('oVirt','cluster_name')
STORAGE_NAME = config.get('oVirt','storage_name')
EXPORT_NAME = config.get('oVirt','export_name')
TEMPLATE_NAME = config.get('oVirt','template_name')


try:
    api=API(url=url,username=username,password=password,insecure=insecure)
except :
    print "can't connect to oVirt server"
    sys.exit(2)

try:
    #vms=api.vms.list(cluster=api.clusters.get(CLUSTER_NAME))
    vms=api.vms.list(cluster='local_cluster')
    
except Exception as e:
  print "fails\n %s " % str(e)