Synnefo » snf-ganeti

#!/usr/bin/python

#

# Copyright (C) 2009, Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Ganeti configuration daemon queries library.

"""

from ganeti import constants

class ConfdQuery(object):

  """Confd Query base class.

  """

  def __init__(self, reader):

    """Constructor for Confd Query

    @type reader: L{ssconf.SimpleConfigReader}

    @param reader: ConfigReader to use to access the config

    """

    self.reader = reader

  def Exec(self, query):

    """Process a single UDP request from a client.

    Different queries should override this function, which by defaults returns

    a "non-implemented" answer.

    @type query: (undefined)

    @param query: ConfdRequest 'query' field

    @rtype: (integer, undefined)

    @return: status and answer to give to the client

    """

    status = constants.CONFD_REPL_STATUS_NOTIMPLEMENTED

    answer = 'not implemented'

    return status, answer

class PingQuery(ConfdQuery):

  """An empty confd query.

  It will return success on an empty argument, and an error on any other argument.

  """

  def Exec(self, query):

    """EmptyQuery main execution

    """

    if query is None:

      status = constants.CONFD_REPL_STATUS_OK

      answer = 'ok'

    else:

      status = constants.CONFD_REPL_STATUS_ERROR

      answer = 'non-empty ping query'

    return status, answer

class NodeRoleQuery(ConfdQuery):

  """An empty confd query.

  It will return success on an empty argument, and an error on any other argument.

  """

  def Exec(self, query):

    """EmptyQuery main execution

    """

    node = query

    if self.reader.GetMasterNode() == node:

      status = constants.CONFD_REPL_STATUS_OK

      answer = constants.CONFD_NODE_ROLE_MASTER

      return status, answer

    flags = self.reader.GetNodeStatusFlags(node)

    if flags is None:

      status = constants.CONFD_REPL_STATUS_ERROR

      answer = constants.CONFD_ERROR_UNKNOWN_ENTRY

      return status, answer

    master_candidate, drained, offline = flags

    if master_candidate:

      answer = constants.CONFD_NODE_ROLE_CANDIDATE

    elif drained:

      answer = constants.CONFD_NODE_ROLE_DRAINED

    elif offline:

      answer = constants.CONFD_NODE_ROLE_OFFLINE

    else:

      answer = constants.CONFD_NODE_ROLE_REGULAR

    return constants.CONFD_REPL_STATUS_OK, answer