Synnefo » snf-ganeti

def CheckStorageTypeEnabled(cluster, storage_type):

  """Helper function to check if a storage type is enabled.

  @type cluster: C{objects.Cluster}

  @param cluster: the cluster's configuration

  @type storage_type: str

  @param storage_type: the storage type to be checked

  """

  assert storage_type is not None

  assert storage_type in constants.VALID_STORAGE_TYPES

  # special case for lvm-pv, because it cannot be enabled

  # via disk templates

  if storage_type == constants.ST_LVM_PV:

    CheckStorageTypeEnabled(cluster, constants.ST_LVM_VG)

  else:

    possible_disk_templates = \

        utils.storage.GetDiskTemplatesOfStorageType(storage_type)

    for disk_template in possible_disk_templates:

      if disk_template in cluster.enabled_disk_templates:

        return

    raise errors.OpPrereqError("No disk template of storage type '%s' is"

                               " enabled in this cluster. Enabled disk"

                               " templates are: %s" % (storage_type,

                               ",".join(cluster.enabled_disk_templates)))