Source Code for Module ganeti.runtime

  1  # 
  2   
  3  # Copyright (C) 2010 Google Inc. 
  4  # 
  5  # This program is free software; you can redistribute it and/or modify 
  6  # it under the terms of the GNU General Public License as published by 
  7  # the Free Software Foundation; either version 2 of the License, or 
  8  # (at your option) any later version. 
  9  # 
 10  # This program is distributed in the hope that it will be useful, but 
 11  # WITHOUT ANY WARRANTY; without even the implied warranty of 
 12  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
 13  # General Public License for more details. 
 14  # 
 15  # You should have received a copy of the GNU General Public License 
 16  # along with this program; if not, write to the Free Software 
 17  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 
 18  # 02110-1301, USA. 
 19   
 20  """Module implementing configuration details at runtime. 
 21   
 22  """ 
 23   
 24   
 25  import grp 
 26  import pwd 
 27  import threading 
 28   
 29  from ganeti import constants 
 30  from ganeti import errors 
 31   
 32   
 33  _priv = None 
 34  _priv_lock = threading.Lock() 
 35   
 36   
 37 -def GetUid(user, _getpwnam): 
 38    """Retrieve the uid from the database. 
 39   
 40    @type user: string 
 41    @param user: The username to retrieve 
 42    @return: The resolved uid 
 43   
 44    """ 
 45    try: 
 46      return _getpwnam(user).pw_uid 
 47    except KeyError, err: 
 48      raise errors.ConfigurationError("User '%s' not found (%s)" % (user, err)) 
 49   
 50   
 51 -def GetGid(group, _getgrnam): 
 52    """Retrieve the gid from the database. 
 53   
 54    @type group: string 
 55    @param group: The group name to retrieve 
 56    @return: The resolved gid 
 57   
 58    """ 
 59    try: 
 60      return _getgrnam(group).gr_gid 
 61    except KeyError, err: 
 62      raise errors.ConfigurationError("Group '%s' not found (%s)" % (group, err)) 
 63   
 64   
 65 -class GetentResolver: 
 66    """Resolves Ganeti uids and gids by name. 
 67   
 68    @ivar masterd_uid: The resolved uid of the masterd user 
 69    @ivar masterd_gid: The resolved gid of the masterd group 
 70    @ivar confd_uid: The resolved uid of the confd user 
 71    @ivar confd_gid: The resolved gid of the confd group 
 72    @ivar rapi_uid: The resolved uid of the rapi user 
 73    @ivar rapi_gid: The resolved gid of the rapi group 
 74    @ivar noded_uid: The resolved uid of the noded user 
 75   
 76    @ivar daemons_gid: The resolved gid of the daemons group 
 77    @ivar admin_gid: The resolved gid of the admin group 
 78    """ 
 79 -  def __init__(self, _getpwnam=pwd.getpwnam, _getgrnam=grp.getgrnam): 
 80      """Initialize the resolver. 
 81   
 82      """ 
 83      # Daemon pairs 
 84      self.masterd_uid = GetUid(constants.MASTERD_USER, _getpwnam) 
 85      self.masterd_gid = GetGid(constants.MASTERD_GROUP, _getgrnam) 
 86   
 87      self.confd_uid = GetUid(constants.CONFD_USER, _getpwnam) 
 88      self.confd_gid = GetGid(constants.CONFD_GROUP, _getgrnam) 
 89   
 90      self.rapi_uid = GetUid(constants.RAPI_USER, _getpwnam) 
 91      self.rapi_gid = GetGid(constants.RAPI_GROUP, _getgrnam) 
 92   
 93      self.noded_uid = GetUid(constants.NODED_USER, _getpwnam) 
 94   
 95      # Misc Ganeti groups 
 96      self.daemons_gid = GetGid(constants.DAEMONS_GROUP, _getgrnam) 
 97      self.admin_gid = GetGid(constants.ADMIN_GROUP, _getgrnam) 
 98   
 99   
100 -def GetEnts(resolver=GetentResolver): 
101    """Singleton wrapper around resolver instance. 
102   
103    As this method is accessed by multiple threads at the same time 
104    we need to take thread-safty carefully 
105   
106    """ 
107    # We need to use the global keyword here 
108    global _priv # pylint: disable-msg=W0603 
109   
110    if not _priv: 
111      _priv_lock.acquire() 
112      try: 
113        if not _priv: 
114          # W0621: Redefine '_priv' from outer scope (used for singleton) 
115          _priv = resolver() # pylint: disable-msg=W0621 
116      finally: 
117        _priv_lock.release() 
118   
119    return _priv 
120