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  from ganeti import utils 
 32   
 33   
 34  _priv = None 
 35  _priv_lock = threading.Lock() 
 36   
 37   
 38 -def GetUid(user, _getpwnam): 
 39    """Retrieve the uid from the database. 
 40   
 41    @type user: string 
 42    @param user: The username to retrieve 
 43    @return: The resolved uid 
 44   
 45    """ 
 46    try: 
 47      return _getpwnam(user).pw_uid 
 48    except KeyError, err: 
 49      raise errors.ConfigurationError("User '%s' not found (%s)" % (user, err)) 
 50   
 51   
 52 -def GetGid(group, _getgrnam): 
 53    """Retrieve the gid from the database. 
 54   
 55    @type group: string 
 56    @param group: The group name to retrieve 
 57    @return: The resolved gid 
 58   
 59    """ 
 60    try: 
 61      return _getgrnam(group).gr_gid 
 62    except KeyError, err: 
 63      raise errors.ConfigurationError("Group '%s' not found (%s)" % (group, err)) 
 64   
 65   
 66 -class GetentResolver: 
 67    """Resolves Ganeti uids and gids by name. 
 68   
 69    @ivar masterd_uid: The resolved uid of the masterd user 
 70    @ivar masterd_gid: The resolved gid of the masterd group 
 71    @ivar confd_uid: The resolved uid of the confd user 
 72    @ivar confd_gid: The resolved gid of the confd group 
 73    @ivar rapi_uid: The resolved uid of the rapi user 
 74    @ivar rapi_gid: The resolved gid of the rapi group 
 75    @ivar noded_uid: The resolved uid of the noded user 
 76   
 77    @ivar daemons_gid: The resolved gid of the daemons group 
 78    @ivar admin_gid: The resolved gid of the admin group 
 79    """ 
 80 -  def __init__(self, _getpwnam=pwd.getpwnam, _getgrnam=grp.getgrnam): 
 81      """Initialize the resolver. 
 82   
 83      """ 
 84      # Daemon pairs 
 85      self.masterd_uid = GetUid(constants.MASTERD_USER, _getpwnam) 
 86      self.masterd_gid = GetGid(constants.MASTERD_GROUP, _getgrnam) 
 87   
 88      self.confd_uid = GetUid(constants.CONFD_USER, _getpwnam) 
 89      self.confd_gid = GetGid(constants.CONFD_GROUP, _getgrnam) 
 90   
 91      self.rapi_uid = GetUid(constants.RAPI_USER, _getpwnam) 
 92      self.rapi_gid = GetGid(constants.RAPI_GROUP, _getgrnam) 
 93   
 94      self.noded_uid = GetUid(constants.NODED_USER, _getpwnam) 
 95      self.noded_gid = GetGid(constants.NODED_GROUP, _getgrnam) 
 96   
 97      # Misc Ganeti groups 
 98      self.daemons_gid = GetGid(constants.DAEMONS_GROUP, _getgrnam) 
 99      self.admin_gid = GetGid(constants.ADMIN_GROUP, _getgrnam) 
100   
101      self._uid2user = { 
102        self.masterd_uid: constants.MASTERD_USER, 
103        self.confd_uid: constants.CONFD_USER, 
104        self.rapi_uid: constants.RAPI_USER, 
105        self.noded_uid: constants.NODED_USER, 
106        } 
107   
108      self._gid2group = { 
109        self.masterd_gid: constants.MASTERD_GROUP, 
110        self.confd_gid: constants.CONFD_GROUP, 
111        self.rapi_gid: constants.RAPI_GROUP, 
112        self.noded_gid: constants.NODED_GROUP, 
113        self.daemons_gid: constants.DAEMONS_GROUP, 
114        self.admin_gid: constants.ADMIN_GROUP, 
115        } 
116   
117      self._user2uid = utils.InvertDict(self._uid2user) 
118      self._group2gid = utils.InvertDict(self._gid2group) 
119   
120 -  def LookupUid(self, uid): 
121      """Looks which Ganeti user belongs to this uid. 
122   
123      @param uid: The uid to lookup 
124      @returns The user name associated with that uid 
125   
126      """ 
127      try: 
128        return self._uid2user[uid] 
129      except KeyError: 
130        raise errors.ConfigurationError("Unknown Ganeti uid '%d'" % uid) 
131   
132 -  def LookupGid(self, gid): 
133      """Looks which Ganeti group belongs to this gid. 
134   
135      @param gid: The gid to lookup 
136      @returns The group name associated with that gid 
137   
138      """ 
139      try: 
140        return self._gid2group[gid] 
141      except KeyError: 
142        raise errors.ConfigurationError("Unknown Ganeti gid '%d'" % gid) 
143   
144 -  def LookupUser(self, name): 
145      """Looks which uid belongs to this name. 
146   
147      @param name: The name to lookup 
148      @returns The uid associated with that user name 
149   
150      """ 
151      try: 
152        return self._user2uid[name] 
153      except KeyError: 
154        raise errors.ConfigurationError("Unknown Ganeti user '%s'" % name) 
155   
156 -  def LookupGroup(self, name): 
157      """Looks which gid belongs to this name. 
158   
159      @param name: The name to lookup 
160      @returns The gid associated with that group name 
161   
162      """ 
163      try: 
164        return self._group2gid[name] 
165      except KeyError: 
166        raise errors.ConfigurationError("Unknown Ganeti group '%s'" % name) 
167   
168   
169 -def GetEnts(resolver=GetentResolver): 
170    """Singleton wrapper around resolver instance. 
171   
172    As this method is accessed by multiple threads at the same time 
173    we need to take thread-safty carefully 
174   
175    """ 
176    # We need to use the global keyword here 
177    global _priv # pylint: disable-msg=W0603 
178   
179    if not _priv: 
180      _priv_lock.acquire() 
181      try: 
182        if not _priv: 
183          # W0621: Redefine '_priv' from outer scope (used for singleton) 
184          _priv = resolver() # pylint: disable-msg=W0621 
185      finally: 
186        _priv_lock.release() 
187   
188    return _priv 
189