Synnefo » snf-ganeti » ganeti-local

#!/usr/bin/python

#

# Copyright (C) 2007 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.

"""Tool to upgrade the configuration file.

This code handles only the types supported by simplejson. As an example, "set"

is a "list". Old Pickle based configurations files are converted to JSON during

the process.

"""

import os

import os.path

import sys

import re

import optparse

import tempfile

import simplejson

from ganeti import utils

from ganeti.cli import AskUser, FORCE_OPT

options = None

args = None

class Error(Exception):

  """Generic exception"""

  pass

# {{{ Support for old Pickle files

class UpgradeDict(dict):

  """Base class for internal config classes.

  """

  def __setstate__(self, state):

    self.update(state)

  def __getstate__(self):

    return self.copy()

def FindGlobal(module, name):

  """Wraps Ganeti config classes to internal ones.

  This function may only return types supported by simplejson.

  """

  if module == "ganeti.objects":

    return UpgradeDict

  elif module == "__builtin__" and name == "set":

    return list

  return getattr(sys.modules[module], name)

def ReadPickleFile(f):

  """Reads an old Pickle configuration.

  """

  import cPickle

  loader = cPickle.Unpickler(f)

  loader.find_global = FindGlobal

  return loader.load()

def IsPickleFile(f):

  """Checks whether a file is using the Pickle format.

  """

  magic = f.read(128)

  try:

    return not re.match('^\s*\{', magic)

  finally:

    f.seek(-len(magic), 1)

# }}}

def ReadJsonFile(f):

  """Reads a JSON file.

  """

  return simplejson.load(f)

def ReadConfig(path):

  """Reads configuration file.

  """

  f = open(path, 'r')

  try:

    if IsPickleFile(f):

      return ReadPickleFile(f)

    else:

      return ReadJsonFile(f)

  finally:

    f.close()

def WriteConfig(path, data):

  """Writes the configuration file.

  """

  if not options.dry_run:

    utils.CreateBackup(path)

  (fd, name) = tempfile.mkstemp(dir=os.path.dirname(path))

  f = os.fdopen(fd, 'w')

  try:

    try:

      simplejson.dump(data, f)

      f.flush()

      if options.dry_run:

        os.unlink(name)

      else:

        os.rename(name, path)

    except:

      os.unlink(name)

      raise

  finally:

    f.close()

def UpdateFromVersion2To3(cfg):

  """Updates the configuration from version 2 to 3.

  """

  if cfg['cluster']['config_version'] != 2:

    return

  # Add port pool

  if 'tcpudp_port_pool' not in cfg['cluster']:

    cfg['cluster']['tcpudp_port_pool'] = []

  # Add bridge settings

  if 'default_bridge' not in cfg['cluster']:

    cfg['cluster']['default_bridge'] = 'xen-br0'

  for inst in cfg['instances'].values():

    for nic in inst['nics']:

      if 'bridge' not in nic:

        nic['bridge'] = None

  cfg['cluster']['config_version'] = 3

# Main program

if __name__ == "__main__":

  program = os.path.basename(sys.argv[0])

  # Option parsing

  parser = optparse.OptionParser()

  parser.add_option('--dry-run', dest='dry_run',

                    action="store_true",

                    help="Try to do the conversion, but don't write "

                      "output file")

  parser.add_option(FORCE_OPT)

  parser.add_option('--verbose', dest='verbose',

                    action="store_true",

                    help="Verbose output")

  (options, args) = parser.parse_args()

  # Option checking

  if args:

    cfg_file = args[0]

  else:

    raise Error("Configuration file not specified")

  if not options.force:

    usertext = ("%s MUST run on the master node. Is this the master "

                "node?" % program)

    if not AskUser(usertext):

      sys.exit(1)

  config = ReadConfig(cfg_file)

  if options.verbose:

    import pprint

    print "Before upgrade:"

    pprint.pprint(config)

    print

  UpdateFromVersion2To3(config)

  if options.verbose:

    print "After upgrade:"

    pprint.pprint(config)

    print

  WriteConfig(cfg_file, config)

  print "The configuration file has been updated successfully. Please run"

  print "  gnt-cluster copyfile %s" % cfg_file

  print "now."

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