Source Code for Module ganeti.runtime

  1  # 
  2  # 
  3   
  4  # Copyright (C) 2010 Google Inc. 
  5  # 
  6  # This program is free software; you can redistribute it and/or modify 
  7  # it under the terms of the GNU General Public License as published by 
  8  # the Free Software Foundation; either version 2 of the License, or 
  9  # (at your option) any later version. 
 10  # 
 11  # This program is distributed in the hope that it will be useful, but 
 12  # WITHOUT ANY WARRANTY; without even the implied warranty of 
 13  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
 14  # General Public License for more details. 
 15  # 
 16  # You should have received a copy of the GNU General Public License 
 17  # along with this program; if not, write to the Free Software 
 18  # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 
 19  # 02110-1301, USA. 
 20   
 21  """Module implementing configuration details at runtime. 
 22   
 23  """ 
 24   
 25   
 26  import grp 
 27  import pwd 
 28  import threading 
 29   
 30  from ganeti import constants 
 31  from ganeti import errors 
 32  from ganeti import utils 
 33   
 34   
 35  _priv = None 
 36  _priv_lock = threading.Lock() 
 37   
 38   
 39 -def GetUid(user, _getpwnam): 
 40    """Retrieve the uid from the database. 
 41   
 42    @type user: string 
 43    @param user: The username to retrieve 
 44    @return: The resolved uid 
 45   
 46    """ 
 47    try: 
 48      return _getpwnam(user).pw_uid 
 49    except KeyError, err: 
 50      raise errors.ConfigurationError("User '%s' not found (%s)" % (user, err)) 
 51   
 52   
 53 -def GetGid(group, _getgrnam): 
 54    """Retrieve the gid from the database. 
 55   
 56    @type group: string 
 57    @param group: The group name to retrieve 
 58    @return: The resolved gid 
 59   
 60    """ 
 61    try: 
 62      return _getgrnam(group).gr_gid 
 63    except KeyError, err: 
 64      raise errors.ConfigurationError("Group '%s' not found (%s)" % (group, err)) 
 65   
 66   
 67 -class GetentResolver: 
 68    """Resolves Ganeti uids and gids by name. 
 69   
 70    @ivar masterd_uid: The resolved uid of the masterd user 
 71    @ivar masterd_gid: The resolved gid of the masterd group 
 72    @ivar confd_uid: The resolved uid of the confd user 
 73    @ivar confd_gid: The resolved gid of the confd group 
 74    @ivar rapi_uid: The resolved uid of the rapi user 
 75    @ivar rapi_gid: The resolved gid of the rapi group 
 76    @ivar noded_uid: The resolved uid of the noded user 
 77   
 78    @ivar daemons_gid: The resolved gid of the daemons group 
 79    @ivar admin_gid: The resolved gid of the admin group 
 80    """ 
 81 -  def __init__(self, _getpwnam=pwd.getpwnam, _getgrnam=grp.getgrnam): 
 82      """Initialize the resolver. 
 83   
 84      """ 
 85      # Daemon pairs 
 86      self.masterd_uid = GetUid(constants.MASTERD_USER, _getpwnam) 
 87      self.masterd_gid = GetGid(constants.MASTERD_GROUP, _getgrnam) 
 88   
 89      self.confd_uid = GetUid(constants.CONFD_USER, _getpwnam) 
 90      self.confd_gid = GetGid(constants.CONFD_GROUP, _getgrnam) 
 91   
 92      self.rapi_uid = GetUid(constants.RAPI_USER, _getpwnam) 
 93      self.rapi_gid = GetGid(constants.RAPI_GROUP, _getgrnam) 
 94   
 95      self.noded_uid = GetUid(constants.NODED_USER, _getpwnam) 
 96      self.noded_gid = GetGid(constants.NODED_GROUP, _getgrnam) 
 97   
 98      # Misc Ganeti groups 
 99      self.daemons_gid = GetGid(constants.DAEMONS_GROUP, _getgrnam) 
100      self.admin_gid = GetGid(constants.ADMIN_GROUP, _getgrnam) 
101   
102      self._uid2user = { 
103        self.masterd_uid: constants.MASTERD_USER, 
104        self.confd_uid: constants.CONFD_USER, 
105        self.rapi_uid: constants.RAPI_USER, 
106        self.noded_uid: constants.NODED_USER, 
107        } 
108   
109      self._gid2group = { 
110        self.masterd_gid: constants.MASTERD_GROUP, 
111        self.confd_gid: constants.CONFD_GROUP, 
112        self.rapi_gid: constants.RAPI_GROUP, 
113        self.noded_gid: constants.NODED_GROUP, 
114        self.daemons_gid: constants.DAEMONS_GROUP, 
115        self.admin_gid: constants.ADMIN_GROUP, 
116        } 
117   
118      self._user2uid = utils.InvertDict(self._uid2user) 
119      self._group2gid = utils.InvertDict(self._gid2group) 
120   
121 -  def LookupUid(self, uid): 
122      """Looks which Ganeti user belongs to this uid. 
123   
124      @param uid: The uid to lookup 
125      @returns The user name associated with that uid 
126   
127      """ 
128      try: 
129        return self._uid2user[uid] 
130      except KeyError: 
131        raise errors.ConfigurationError("Unknown Ganeti uid '%d'" % uid) 
132   
133 -  def LookupGid(self, gid): 
134      """Looks which Ganeti group belongs to this gid. 
135   
136      @param gid: The gid to lookup 
137      @returns The group name associated with that gid 
138   
139      """ 
140      try: 
141        return self._gid2group[gid] 
142      except KeyError: 
143        raise errors.ConfigurationError("Unknown Ganeti gid '%d'" % gid) 
144   
145 -  def LookupUser(self, name): 
146      """Looks which uid belongs to this name. 
147   
148      @param name: The name to lookup 
149      @returns The uid associated with that user name 
150   
151      """ 
152      try: 
153        return self._user2uid[name] 
154      except KeyError: 
155        raise errors.ConfigurationError("Unknown Ganeti user '%s'" % name) 
156   
157 -  def LookupGroup(self, name): 
158      """Looks which gid belongs to this name. 
159   
160      @param name: The name to lookup 
161      @returns The gid associated with that group name 
162   
163      """ 
164      try: 
165        return self._group2gid[name] 
166      except KeyError: 
167        raise errors.ConfigurationError("Unknown Ganeti group '%s'" % name) 
168   
169   
170 -def GetEnts(resolver=GetentResolver): 
171    """Singleton wrapper around resolver instance. 
172   
173    As this method is accessed by multiple threads at the same time 
174    we need to take thread-safty carefully 
175   
176    """ 
177    # We need to use the global keyword here 
178    global _priv # pylint: disable=W0603 
179   
180    if not _priv: 
181      _priv_lock.acquire() 
182      try: 
183        if not _priv: 
184          # W0621: Redefine '_priv' from outer scope (used for singleton) 
185          _priv = resolver() # pylint: disable=W0621 
186      finally: 
187        _priv_lock.release() 
188   
189    return _priv 
190