Synnefo » snf-ganeti » ganeti-local

#!/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.

"""

import logging

from ganeti import constants

# constants for some common errors to return from a query

QUERY_UNKNOWN_ENTRY_ERROR = (constants.CONFD_REPL_STATUS_ERROR,

                             constants.CONFD_ERROR_UNKNOWN_ENTRY)

QUERY_INTERNAL_ERROR = (constants.CONFD_REPL_STATUS_ERROR,

                        constants.CONFD_ERROR_INTERNAL)

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):

    """PingQuery 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):

  """A query for the role of a node.

  It will return one of CONFD_NODE_ROLE_*, or an error for non-existing nodes.

  """

  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:

      return QUERY_UNKNOWN_ENTRY_ERROR

    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

class InstanceIpToNodePrimaryIpQuery(ConfdQuery):

  """A query for the location of an instance's ip.

  It returns the primary ip of the node hosting the instance having the

  requested ip address, or an error if no such address is known.

  """

  def Exec(self, query):

    """InstanceIpToNodePrimaryIpQuery main execution.

    """

    instance_ip = query

    instance = self.reader.GetInstanceByIp(instance_ip)

    if instance is None:

      return QUERY_UNKNOWN_ENTRY_ERROR

    pnode = self.reader.GetInstancePrimaryNode(instance)

    if pnode is None:

      # this shouldn't happen

      logging.error("Internal configuration inconsistent (instance-to-pnode)")

      return QUERY_INTERNAL_ERROR

    pnode_primary_ip = self.reader.GetNodePrimaryIp(pnode)

    if pnode_primary_ip is None:

      # this shouldn't happen

      logging.error("Internal configuration inconsistent (node-to-primary-ip)")

      return QUERY_INTERNAL_ERROR

    return constants.CONFD_REPL_STATUS_OK, pnode_primary_ip