Adding a runtime configuration library

This is used to expand the users/group names just once at
initial call.

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Makefile.am

@@ -124,6 +124,7 @@ pkgpython_PYTHON = \
 	lib/objects.py \
 	lib/opcodes.py \
 	lib/rpc.py \
+	lib/runtime.py \
 	lib/serializer.py \
 	lib/ssconf.py \
 	lib/ssh.py \
@@ -393,6 +394,7 @@ python_tests = \
 	test/ganeti.rapi.resources_unittest.py \
 	test/ganeti.rapi.rlib2_unittest.py \
 	test/ganeti.rpc_unittest.py \
+	test/ganeti.runtime_unittest.py \
 	test/ganeti.serializer_unittest.py \
 	test/ganeti.ssh_unittest.py \
 	test/ganeti.uidpool_unittest.py \
@@ -565,8 +567,14 @@ lib/_autoconf.py: Makefile stamp-directories vcs-version
 	  echo "DRBD_BARRIERS = $(DRBD_BARRIERS)"; \
 	  echo "SYSLOG_USAGE = '$(SYSLOG_USAGE)'"; \
 	  echo "DAEMONS_GROUP = '$(DAEMONS_GROUP)'"; \
+	  echo "ADMIN_GROUP = '$(ADMIN_GROUP)'"; \
 	  echo "MASTERD_USER = '$(MASTERD_USER)'"; \
+	  echo "MASTERD_GROUP = '$(MASTERD_GROUP)'"; \
 	  echo "RAPI_USER = '$(RAPI_USER)'"; \
+	  echo "RAPI_GROUP = '$(RAPI_GROUP)'"; \
+	  echo "CONFD_USER = '$(CONFD_USER)'"; \
+	  echo "CONFD_GROUP = '$(CONFD_GROUP)'"; \
+	  echo "NODED_USER = '$(NODED_USER)'"; \
 	  echo "VCS_VERSION = '$$VCSVER'"; \
 	} > $@
 

lib/constants.py

@@ -86,8 +86,14 @@ CONFIG_VERSION = BuildVersion(CONFIG_MAJOR, CONFIG_MINOR, CONFIG_REVISION)
 
 # user separation
 DAEMONS_GROUP = _autoconf.DAEMONS_GROUP
+ADMIN_GROUP = _autoconf.ADMIN_GROUP
 MASTERD_USER = _autoconf.MASTERD_USER
+MASTERD_GROUP = _autoconf.MASTERD_GROUP
 RAPI_USER = _autoconf.RAPI_USER
+RAPI_GROUP = _autoconf.RAPI_GROUP
+CONFD_USER = _autoconf.CONFD_USER
+CONFD_GROUP = _autoconf.CONFD_GROUP
+NODED_USER = _autoconf.NODED_USER
 
 # file paths
 DATA_DIR = _autoconf.LOCALSTATEDIR + "/lib/ganeti"

lib/runtime.py

+#
+
+# Copyright (C) 2010 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.
+
+"""Module implementing configuration details at runtime.
+
+"""
+
+
+import grp
+import pwd
+import threading
+
+from ganeti import constants
+from ganeti import errors
+
+
+_priv = None
+_priv_lock = threading.Lock()
+
+
+def GetUid(user, _getpwnam):
+  """Retrieve the uid from the database.
+
+  @type user: string
+  @param user: The username to retrieve
+  @return: The resolved uid
+
+  """
+  try:
+    return _getpwnam(user).pw_uid
+  except KeyError, err:
+    raise errors.ConfigurationError("User '%s' not found (%s)" % (user, err))
+
+
+def GetGid(group, _getgrnam):
+  """Retrieve the gid from the database.
+
+  @type group: string
+  @param group: The group name to retrieve
+  @return: The resolved gid
+
+  """
+  try:
+    return _getgrnam(group).gr_gid
+  except KeyError, err:
+    raise errors.ConfigurationError("Group '%s' not found (%s)" % (group, err))
+
+
+class GetentResolver:
+  """Resolves Ganeti uids and gids by name.
+
+  @ivar masterd_uid: The resolved uid of the masterd user
+  @ivar masterd_gid: The resolved gid of the masterd group
+  @ivar confd_uid: The resolved uid of the confd user
+  @ivar confd_gid: The resolved gid of the confd group
+  @ivar rapi_uid: The resolved uid of the rapi user
+  @ivar rapi_gid: The resolved gid of the rapi group
+  @ivar noded_uid: The resolved uid of the noded user
+
+  @ivar daemons_gid: The resolved gid of the daemons group
+  @ivar admin_gid: The resolved gid of the admin group
+  """
+  def __init__(self, _getpwnam=pwd.getpwnam, _getgrnam=grp.getgrnam):
+    """Initialize the resolver.
+
+    """
+    # Daemon pairs
+    self.masterd_uid = GetUid(constants.MASTERD_USER, _getpwnam)
+    self.masterd_gid = GetGid(constants.MASTERD_GROUP, _getgrnam)
+
+    self.confd_uid = GetUid(constants.CONFD_USER, _getpwnam)
+    self.confd_gid = GetGid(constants.CONFD_GROUP, _getgrnam)
+
+    self.rapi_uid = GetUid(constants.RAPI_USER, _getpwnam)
+    self.rapi_gid = GetGid(constants.RAPI_GROUP, _getgrnam)
+
+    self.noded_uid = GetUid(constants.NODED_USER, _getpwnam)
+
+    # Misc Ganeti groups
+    self.daemons_gid = GetGid(constants.DAEMONS_GROUP, _getgrnam)
+    self.admin_gid = GetGid(constants.ADMIN_GROUP, _getgrnam)
+
+
+def GetEnts(resolver=GetentResolver):
+  """Singleton wrapper around resolver instance.
+
+  As this method is accessed by multiple threads at the same time
+  we need to take thread-safty carefully
+
+  """
+  # We need to use the global keyword here
+  global _priv # pylint: disable-msg=W0603
+
+  if not _priv:
+    _priv_lock.acquire()
+    try:
+      if not _priv:
+        # W0621: Redefine '_priv' from outer scope (used for singleton)
+        _priv = resolver() # pylint: disable-msg=W0621
+    finally:
+      _priv_lock.release()
+
+  return _priv
+

test/ganeti.runtime_unittest.py

+#!/usr/bin/python
+#
+
+# Copyright (C) 2010 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.
+
+"""Script for testing ganeti.runtime"""
+
+from ganeti import constants
+from ganeti import errors
+from ganeti import runtime
+
+import testutils
+
+
+class _EntStub:
+  def __init__(self, uid=None, gid=None):
+    self.pw_uid = uid
+    self.gr_gid = gid
+
+
+def _StubGetpwnam(user):
+  users = {
+    constants.MASTERD_USER: _EntStub(uid=0),
+    constants.CONFD_USER: _EntStub(uid=1),
+    constants.RAPI_USER: _EntStub(uid=2),
+    constants.NODED_USER: _EntStub(uid=3),
+    }
+  return users[user]
+
+
+def _StubGetgrnam(group):
+  groups = {
+    constants.MASTERD_GROUP: _EntStub(gid=0),
+    constants.CONFD_GROUP: _EntStub(gid=1),
+    constants.RAPI_GROUP: _EntStub(gid=2),
+    constants.DAEMONS_GROUP: _EntStub(gid=3),
+    constants.ADMIN_GROUP: _EntStub(gid=4),
+    }
+  return groups[group]
+
+
+def _RaisingStubGetpwnam(user):
+  raise KeyError("user not found")
+
+
+def _RaisingStubGetgrnam(group):
+  raise KeyError("group not found")
+
+
+class ResolverStubRaising(object):
+  def __init__(self):
+    raise errors.ConfigurationError("No entries")
+
+
+class TestErrors(testutils.GanetiTestCase):
+  def testEverythingSuccessful(self):
+    resolver = runtime.GetentResolver(_getpwnam=_StubGetpwnam,
+                                      _getgrnam=_StubGetgrnam)
+
+    self.assertEqual(resolver.masterd_uid,
+                     _StubGetpwnam(constants.MASTERD_USER).pw_uid)
+    self.assertEqual(resolver.masterd_gid,
+                     _StubGetgrnam(constants.MASTERD_GROUP).gr_gid)
+    self.assertEqual(resolver.confd_uid,
+                     _StubGetpwnam(constants.CONFD_USER).pw_uid)
+    self.assertEqual(resolver.confd_gid,
+                     _StubGetgrnam(constants.CONFD_GROUP).gr_gid)
+    self.assertEqual(resolver.rapi_uid,
+                     _StubGetpwnam(constants.RAPI_USER).pw_uid)
+    self.assertEqual(resolver.rapi_gid,
+                     _StubGetgrnam(constants.RAPI_GROUP).gr_gid)
+    self.assertEqual(resolver.noded_uid,
+                     _StubGetpwnam(constants.NODED_USER).pw_uid)
+
+    self.assertEqual(resolver.daemons_gid,
+                     _StubGetgrnam(constants.DAEMONS_GROUP).gr_gid)
+    self.assertEqual(resolver.admin_gid,
+                     _StubGetgrnam(constants.ADMIN_GROUP).gr_gid)
+
+  def testUserNotFound(self):
+    self.assertRaises(errors.ConfigurationError, runtime.GetentResolver,
+                      _getpwnam=_RaisingStubGetpwnam, _getgrnam=_StubGetgrnam)
+
+  def testGroupNotFound(self):
+    self.assertRaises(errors.ConfigurationError, runtime.GetentResolver,
+                      _getpwnam=_StubGetpwnam, _getgrnam=_RaisingStubGetgrnam)
+
+  def testUserNotFoundGetEnts(self):
+    self.assertRaises(errors.ConfigurationError, runtime.GetEnts,
+                      resolver=ResolverStubRaising)
+
+
+if __name__ == "__main__":
+  testutils.GanetiTestProgram()