Synnefo » snf-ganeti

import itertools

  @locking.ssynchronized(_config_lock)

  def AssignGroupNodes(self, mods):

    """Changes the group of a number of nodes.

    @type mods: list of tuples; (node name, new group UUID)

    @param modes: Node membership modifications

    """

    groups = self._config_data.nodegroups

    nodes = self._config_data.nodes

    resmod = []

    # Try to resolve names/UUIDs first

    for (node_name, new_group_uuid) in mods:

      try:

        node = nodes[node_name]

      except KeyError:

        raise errors.ConfigurationError("Unable to find node '%s'" % node_name)

      if node.group == new_group_uuid:

        # Node is being assigned to its current group

        logging.debug("Node '%s' was assigned to its current group (%s)",

                      node_name, node.group)

        continue

      # Try to find current group of node

      try:

        old_group = groups[node.group]

      except KeyError:

        raise errors.ConfigurationError("Unable to find old group '%s'" %

                                        node.group)

      # Try to find new group for node

      try:

        new_group = groups[new_group_uuid]

      except KeyError:

        raise errors.ConfigurationError("Unable to find new group '%s'" %

                                        new_group_uuid)

      assert node.name in old_group.members, \

        ("Inconsistent configuration: node '%s' not listed in members for its"

         " old group '%s'" % (node.name, old_group.uuid))

      assert node.name not in new_group.members, \

        ("Inconsistent configuration: node '%s' already listed in members for"

         " its new group '%s'" % (node.name, new_group.uuid))

      resmod.append((node, old_group, new_group))

    # Apply changes

    for (node, old_group, new_group) in resmod:

      assert node.uuid != new_group.uuid and old_group.uuid != new_group.uuid, \

        "Assigning to current group is not possible"

      node.group = new_group.uuid

      # Update members of involved groups

      if node.name in old_group.members:

        old_group.members.remove(node.name)

      if node.name not in new_group.members:

        new_group.members.append(node.name)

    # Update timestamps and serials (only once per node/group object)

    now = time.time()

    for obj in frozenset(itertools.chain(*resmod)): # pylint: disable-msg=W0142

      obj.serial_no += 1

      obj.mtime = now

    # Force ssconf update

    self._config_data.cluster.serial_no += 1

    self._WriteConfig()