Synnefo » snf-ganeti

class LUInstanceSnapshot(LogicalUnit):

  """Take a snapshot of the instance.

  """

  HPATH = "instance-snapshot"

  HTYPE = constants.HTYPE_INSTANCE

  REQ_BGL = False

  def ExpandNames(self):

    self._ExpandAndLockInstance()

  def BuildHooksEnv(self):

    """Build hooks env.

    This runs on master, primary and secondary nodes of the instance.

    """

    return BuildInstanceHookEnvByObject(self, self.instance)

  def BuildHooksNodes(self):

    """Build hooks nodes.

    """

    nl = [self.cfg.GetMasterNode()] + list(self.instance.all_nodes)

    return (nl, nl)

  def CheckPrereq(self):

    """Check prerequisites.

    This checks that the instance is in the cluster and is not running.

    """

    instance = self.cfg.GetInstanceInfo(self.op.instance_name)

    assert instance is not None, \

      "Cannot retrieve locked instance %s" % self.op.instance_name

    CheckNodeOnline(self, instance.primary_node, "Instance primary node"

                    " offline, cannot snapshot")

    #if not instance.disk_template == constants.ST_EXT:

    #  raise errors.OpPrereqError("Instance '%s' disk templates is not 'ext'" %

    #                             self.op.instance_name,

    #                             errors.ECODE_INVAL)

    #CheckInstanceState(self, instance, INSTANCE_DOWN, msg="cannot reinstall")

    self.instance = instance

  def Exec(self, feedback_fn):

    """Take a snapshot of the instance the instance.

    """

    inst = self.instance

    for (idx, disk) in enumerate(inst.disks):

        node_uuid = inst.primary_node

        self.cfg.SetDiskID(disk, node_uuid)

        feedback_fn("Taking a snapshot of instance...")

        info = "snapshot:%s" % self.op.snapshot_name

        result = self.rpc.call_blockdev_setinfo(node_uuid, disk, info)

        result.Raise("Could not take a snapshot for instance %s disk %s"

                     " on node %s" % (inst, disk, inst.primary_node))