Synnefo » snf-ganeti » ganeti-local

from ganeti import utils

def _CheckNodeGroupInstances(cfg, group_uuid, owned_instances):

  """Checks if the instances in a node group are still correct.

  @type cfg: L{config.ConfigWriter}

  @param cfg: The cluster configuration

  @type group_uuid: string

  @param group_uuid: Node group UUID

  @type owned_instances: set or frozenset

  @param owned_instances: List of currently owned instances

  """

  wanted_instances = cfg.GetNodeGroupInstances(group_uuid)

  if owned_instances != wanted_instances:

    raise errors.OpPrereqError("Instances in node group '%s' changed since"

                               " locks were acquired, wanted '%s', have '%s';"

                               " retry the operation" %

                               (group_uuid,

                                utils.CommaJoin(wanted_instances),

                                utils.CommaJoin(owned_instances)),

                               errors.ECODE_STATE)

  return wanted_instances