Allow querying of variable number of parameters

[ganeti-local] / lib / objects.py

diff --git a/lib/objects.py b/lib/objects.py
index 0d409cc..6c74876 100644 (file)
--- a/lib/objects.py
+++ b/lib/objects.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#

 #
 
 # Copyright (C) 2006, 2007 Google Inc.
 #
 
 # Copyright (C) 2006, 2007 Google Inc.

@@ -27,10 +27,10 @@ pass to and from external parties.
 """
 
 
 """
 
 

-import cPickle
-from cStringIO import StringIO

 import ConfigParser
 import re
 import ConfigParser
 import re

+import copy
+from cStringIO import StringIO

 
 from ganeti import errors
 from ganeti import constants
 
 from ganeti import errors
 from ganeti import constants

@@ -56,8 +56,8 @@ class ConfigObject(object):
   __slots__ = []
 
   def __init__(self, **kwargs):
   __slots__ = []
 
   def __init__(self, **kwargs):

-    for i in kwargs:
-      setattr(self, i, kwargs[i])
+    for k, v in kwargs.iteritems():
+      setattr(self, k, v)

 
   def __getattr__(self, name):
     if name not in self.__slots__:
 
   def __getattr__(self, name):
     if name not in self.__slots__:

@@ -82,76 +82,88 @@ class ConfigObject(object):
       if name in self.__slots__:
         setattr(self, name, state[name])
 
       if name in self.__slots__:
         setattr(self, name, state[name])
 

-  @staticmethod
-  def FindGlobal(module, name):
-    """Function filtering the allowed classes to be un-pickled.
-
-    Currently, we only allow the classes from this module which are
-    derived from ConfigObject.
-
-    """
-    # Also support the old module name (ganeti.config)
-    cls = None
-    if module == "ganeti.config" or module == "ganeti.objects":
-      if name == "ConfigData":
-        cls = ConfigData
-      elif name == "NIC":
-        cls = NIC
-      elif name == "Disk" or name == "BlockDev":
-        cls = Disk
-      elif name == "Instance":
-        cls = Instance
-      elif name == "OS":
-        cls = OS
-      elif name == "Node":
-        cls = Node
-      elif name == "Cluster":
-        cls = Cluster
-    elif module == "__builtin__":
-      if name == "set":
-        cls = set
-    if cls is None:
-      raise cPickle.UnpicklingError("Class %s.%s not allowed due to"
-                                    " security concerns" % (module, name))
-    return cls
-
-  def Dump(self, fobj):
-    """Dump this instance to a file object.
-
-    Note that we use the HIGHEST_PROTOCOL, as it brings benefits for
-    the new classes.
-
-    """
-    dumper = cPickle.Pickler(fobj, cPickle.HIGHEST_PROTOCOL)
-    dumper.dump(self)
+  def ToDict(self):
+    """Convert to a dict holding only standard python types.

 
 

-  @staticmethod
-  def Load(fobj):
-    """Unpickle data from the given stream.
+    The generic routine just dumps all of this object's attributes in
+    a dict. It does not work if the class has children who are
+    ConfigObjects themselves (e.g. the nics list in an Instance), in
+    which case the object should subclass the function in order to
+    make sure all objects returned are only standard python types.
+
+    """
+    return dict([(k, getattr(self, k, None)) for k in self.__slots__])
+
+  @classmethod
+  def FromDict(cls, val):
+    """Create an object from a dictionary.

 
 

-    This uses the `FindGlobal` function to filter the allowed classes.
+    This generic routine takes a dict, instantiates a new instance of
+    the given class, and sets attributes based on the dict content.
+
+    As for `ToDict`, this does not work if the class has children
+    who are ConfigObjects themselves (e.g. the nics list in an
+    Instance), in which case the object should subclass the function
+    and alter the objects.

 
     """
 
     """

-    loader = cPickle.Unpickler(fobj)
-    loader.find_global = ConfigObject.FindGlobal
-    return loader.load()
+    if not isinstance(val, dict):
+      raise errors.ConfigurationError("Invalid object passed to FromDict:"
+                                      " expected dict, got %s" % type(val))
+    val_str = dict([(str(k), v) for k, v in val.iteritems()])
+    obj = cls(**val_str)
+    return obj

 
 

-  def Dumps(self):
-    """Dump this instance and return the string representation."""
-    buf = StringIO()
-    self.Dump(buf)
-    return buf.getvalue()
+  @staticmethod
+  def _ContainerToDicts(container):
+    """Convert the elements of a container to standard python types.
+
+    This method converts a container with elements derived from
+    ConfigData to standard python types. If the container is a dict,
+    we don't touch the keys, only the values.
+
+    """
+    if isinstance(container, dict):
+      ret = dict([(k, v.ToDict()) for k, v in container.iteritems()])
+    elif isinstance(container, (list, tuple, set, frozenset)):
+      ret = [elem.ToDict() for elem in container]
+    else:
+      raise TypeError("Invalid type %s passed to _ContainerToDicts" %
+                      type(container))
+    return ret

 
   @staticmethod
 
   @staticmethod

-  def Loads(data):
-    """Load data from a string."""
-    return ConfigObject.Load(StringIO(data))
+  def _ContainerFromDicts(source, c_type, e_type):
+    """Convert a container from standard python types.

 
 

+    This method converts a container with standard python types to
+    ConfigData objects. If the container is a dict, we don't touch the
+    keys, only the values.

 
 

-class TaggableObject(object):
+    """
+    if not isinstance(c_type, type):
+      raise TypeError("Container type %s passed to _ContainerFromDicts is"
+                      " not a type" % type(c_type))
+    if c_type is dict:
+      ret = dict([(k, e_type.FromDict(v)) for k, v in source.iteritems()])
+    elif c_type in (list, tuple, set, frozenset):
+      ret = c_type([e_type.FromDict(elem) for elem in source])
+    else:
+      raise TypeError("Invalid container type %s passed to"
+                      " _ContainerFromDicts" % c_type)
+    return ret
+
+  def __repr__(self):
+    """Implement __repr__ for ConfigObjects."""
+    return repr(self.ToDict())
+
+
+class TaggableObject(ConfigObject):

   """An generic class supporting tags.
 
   """
   """An generic class supporting tags.
 
   """

+  __slots__ = ConfigObject.__slots__ + ["tags"]
+

   @staticmethod
   def ValidateTag(tag):
     """Check if a tag is valid.
   @staticmethod
   def ValidateTag(tag):
     """Check if a tag is valid.

@@ -163,7 +175,8 @@ class TaggableObject(object):
     if not isinstance(tag, basestring):
       raise errors.TagError("Invalid tag type (not a string)")
     if len(tag) > constants.MAX_TAG_LEN:
     if not isinstance(tag, basestring):
       raise errors.TagError("Invalid tag type (not a string)")
     if len(tag) > constants.MAX_TAG_LEN:

-      raise errors.TagError("Tag too long (>%d)" % constants.MAX_TAG_LEN)
+      raise errors.TagError("Tag too long (>%d characters)" %
+                            constants.MAX_TAG_LEN)

     if not tag:
       raise errors.TagError("Tags cannot be empty")
     if not re.match("^[ \w.+*/:-]+$", tag):
     if not tag:
       raise errors.TagError("Tags cannot be empty")
     if not re.match("^[ \w.+*/:-]+$", tag):

@@ -199,10 +212,58 @@ class TaggableObject(object):
     except KeyError:
       raise errors.TagError("Tag not found")
 
     except KeyError:
       raise errors.TagError("Tag not found")
 

+  def ToDict(self):
+    """Taggable-object-specific conversion to standard python types.
+
+    This replaces the tags set with a list.
+
+    """
+    bo = super(TaggableObject, self).ToDict()
+
+    tags = bo.get("tags", None)
+    if isinstance(tags, set):
+      bo["tags"] = list(tags)
+    return bo
+
+  @classmethod
+  def FromDict(cls, val):
+    """Custom function for instances.
+
+    """
+    obj = super(TaggableObject, cls).FromDict(val)
+    if hasattr(obj, "tags") and isinstance(obj.tags, list):
+      obj.tags = set(obj.tags)
+    return obj
+

 
 class ConfigData(ConfigObject):
   """Top-level config object."""
 
 class ConfigData(ConfigObject):
   """Top-level config object."""

-  __slots__ = ["cluster", "nodes", "instances"]
+  __slots__ = ["version", "cluster", "nodes", "instances", "serial_no"]
+
+  def ToDict(self):
+    """Custom function for top-level config data.
+
+    This just replaces the list of instances, nodes and the cluster
+    with standard python types.
+
+    """
+    mydict = super(ConfigData, self).ToDict()
+    mydict["cluster"] = mydict["cluster"].ToDict()
+    for key in "nodes", "instances":
+      mydict[key] = self._ContainerToDicts(mydict[key])
+
+    return mydict
+
+  @classmethod
+  def FromDict(cls, val):
+    """Custom function for top-level config data
+
+    """
+    obj = super(ConfigData, cls).FromDict(val)
+    obj.cluster = Cluster.FromDict(obj.cluster)
+    obj.nodes = cls._ContainerFromDicts(obj.nodes, dict, Node)
+    obj.instances = cls._ContainerFromDicts(obj.instances, dict, Instance)
+    return obj

 
 
 class NIC(ConfigObject):
 
 
 class NIC(ConfigObject):

@@ -217,15 +278,43 @@ class Disk(ConfigObject):
 
   def CreateOnSecondary(self):
     """Test if this device needs to be created on a secondary node."""
 
   def CreateOnSecondary(self):
     """Test if this device needs to be created on a secondary node."""

-    return self.dev_type in ("drbd", "lvm")
+    return self.dev_type in (constants.LD_DRBD8, constants.LD_LV)

 
   def AssembleOnSecondary(self):
     """Test if this device needs to be assembled on a secondary node."""
 
   def AssembleOnSecondary(self):
     """Test if this device needs to be assembled on a secondary node."""

-    return self.dev_type in ("drbd", "lvm")
+    return self.dev_type in (constants.LD_DRBD8, constants.LD_LV)

 
   def OpenOnSecondary(self):
     """Test if this device needs to be opened on a secondary node."""
 
   def OpenOnSecondary(self):
     """Test if this device needs to be opened on a secondary node."""

-    return self.dev_type in ("lvm",)
+    return self.dev_type in (constants.LD_LV,)
+
+  def StaticDevPath(self):
+    """Return the device path if this device type has a static one.
+
+    Some devices (LVM for example) live always at the same /dev/ path,
+    irrespective of their status. For such devices, we return this
+    path, for others we return None.
+
+    """
+    if self.dev_type == constants.LD_LV:
+      return "/dev/%s/%s" % (self.logical_id[0], self.logical_id[1])
+    return None
+
+  def ChildrenNeeded(self):
+    """Compute the needed number of children for activation.
+
+    This method will return either -1 (all children) or a positive
+    number denoting the minimum number of children needed for
+    activation (only mirrored devices will usually return >=0).
+
+    Currently, only DRBD8 supports diskless activation (therefore we
+    return 0), for all other we keep the previous semantics and return
+    -1.
+
+    """
+    if self.dev_type == constants.LD_DRBD8:
+      return 0
+    return -1

 
   def GetNodes(self, node):
     """This function returns the nodes this device lives on.
 
   def GetNodes(self, node):
     """This function returns the nodes this device lives on.

@@ -236,9 +325,9 @@ class Disk(ConfigObject):
     devices needs to (or can) be assembled.
 
     """
     devices needs to (or can) be assembled.
 
     """

-    if self.dev_type == "lvm" or self.dev_type == "md_raid1":
+    if self.dev_type in [constants.LD_LV, constants.LD_FILE]:

       result = [node]
       result = [node]

-    elif self.dev_type == "drbd":
+    elif self.dev_type in constants.LDS_DRBD:

       result = [self.logical_id[0], self.logical_id[1]]
       if node not in result:
         raise errors.ConfigurationError("DRBD device passed unknown node")
       result = [self.logical_id[0], self.logical_id[1]]
       if node not in result:
         raise errors.ConfigurationError("DRBD device passed unknown node")

@@ -251,12 +340,9 @@ class Disk(ConfigObject):
 
     This method, given the node on which the parent disk lives, will
     return the list of all (node, disk) pairs which describe the disk
 
     This method, given the node on which the parent disk lives, will
     return the list of all (node, disk) pairs which describe the disk

-    tree in the most compact way. For example, a md/drbd/lvm stack
-    will be returned as (primary_node, md) and (secondary_node, drbd)
-    which represents all the top-level devices on the nodes. This
-    means that on the primary node we need to activate the the md (and
-    recursively all its children) and on the secondary node we need to
-    activate the drbd device (and its children, the two lvm volumes).
+    tree in the most compact way. For example, a drbd/lvm stack
+    will be returned as (primary_node, drbd) and (secondary_node, drbd)
+    which represents all the top-level devices on the nodes.

 
     """
     my_nodes = self.GetNodes(parent_node)
 
     """
     my_nodes = self.GetNodes(parent_node)

@@ -284,20 +370,149 @@ class Disk(ConfigObject):
             # be different)
     return result
 
             # be different)
     return result
 

+  def RecordGrow(self, amount):
+    """Update the size of this disk after growth.
+
+    This method recurses over the disks's children and updates their
+    size correspondigly. The method needs to be kept in sync with the
+    actual algorithms from bdev.
+
+    """
+    if self.dev_type == constants.LD_LV:
+      self.size += amount
+    elif self.dev_type == constants.LD_DRBD8:
+      if self.children:
+        self.children[0].RecordGrow(amount)
+      self.size += amount
+    else:
+      raise errors.ProgrammerError("Disk.RecordGrow called for unsupported"
+                                   " disk type %s" % self.dev_type)
+
+  def SetPhysicalID(self, target_node, nodes_ip):
+    """Convert the logical ID to the physical ID.
+
+    This is used only for drbd, which needs ip/port configuration.
+
+    The routine descends down and updates its children also, because
+    this helps when the only the top device is passed to the remote
+    node.

 
 

-class Instance(ConfigObject, TaggableObject):
+    Arguments:
+      - target_node: the node we wish to configure for
+      - nodes_ip: a mapping of node name to ip
+
+    The target_node must exist in in nodes_ip, and must be one of the
+    nodes in the logical ID for each of the DRBD devices encountered
+    in the disk tree.
+
+    """
+    if self.children:
+      for child in self.children:
+        child.SetPhysicalID(target_node, nodes_ip)
+
+    if self.logical_id is None and self.physical_id is not None:
+      return
+    if self.dev_type in constants.LDS_DRBD:
+      pnode, snode, port, pminor, sminor, secret = self.logical_id
+      if target_node not in (pnode, snode):
+        raise errors.ConfigurationError("DRBD device not knowing node %s" %
+                                        target_node)
+      pnode_ip = nodes_ip.get(pnode, None)
+      snode_ip = nodes_ip.get(snode, None)
+      if pnode_ip is None or snode_ip is None:
+        raise errors.ConfigurationError("Can't find primary or secondary node"
+                                        " for %s" % str(self))
+      p_data = (pnode_ip, port)
+      s_data = (snode_ip, port)
+      if pnode == target_node:
+        self.physical_id = p_data + s_data + (pminor, secret)
+      else: # it must be secondary, we tested above
+        self.physical_id = s_data + p_data + (sminor, secret)
+    else:
+      self.physical_id = self.logical_id
+    return
+
+  def ToDict(self):
+    """Disk-specific conversion to standard python types.
+
+    This replaces the children lists of objects with lists of
+    standard python types.
+
+    """
+    bo = super(Disk, self).ToDict()
+
+    for attr in ("children",):
+      alist = bo.get(attr, None)
+      if alist:
+        bo[attr] = self._ContainerToDicts(alist)
+    return bo
+
+  @classmethod
+  def FromDict(cls, val):
+    """Custom function for Disks
+
+    """
+    obj = super(Disk, cls).FromDict(val)
+    if obj.children:
+      obj.children = cls._ContainerFromDicts(obj.children, list, Disk)
+    if obj.logical_id and isinstance(obj.logical_id, list):
+      obj.logical_id = tuple(obj.logical_id)
+    if obj.physical_id and isinstance(obj.physical_id, list):
+      obj.physical_id = tuple(obj.physical_id)
+    if obj.dev_type in constants.LDS_DRBD:
+      # we need a tuple of length six here
+      if len(obj.logical_id) < 6:
+        obj.logical_id += (None,) * (6 - len(obj.logical_id))
+    return obj
+
+  def __str__(self):
+    """Custom str() formatter for disks.
+
+    """
+    if self.dev_type == constants.LD_LV:
+      val =  "<LogicalVolume(/dev/%s/%s" % self.logical_id
+    elif self.dev_type in constants.LDS_DRBD:
+      val = "<DRBD8("
+      if self.physical_id is None:
+        phy = "unconfigured"
+      else:
+        phy = ("configured as %s:%s %s:%s" %
+               (self.physical_id[0], self.physical_id[1],
+                self.physical_id[2], self.physical_id[3]))
+
+      val += ("hosts=%s-%s, port=%s, %s, " %
+              (self.logical_id[0], self.logical_id[1], self.logical_id[2],
+               phy))
+      if self.children and self.children.count(None) == 0:
+        val += "backend=%s, metadev=%s" % (self.children[0], self.children[1])
+      else:
+        val += "no local storage"
+    else:
+      val = ("<Disk(type=%s, logical_id=%s, physical_id=%s, children=%s" %
+             (self.dev_type, self.logical_id, self.physical_id, self.children))
+    if self.iv_name is None:
+      val += ", not visible"
+    else:
+      val += ", visible as /dev/%s" % self.iv_name
+    val += ", size=%dm)>" % self.size
+    return val
+
+
+class Instance(TaggableObject):

   """Config object representing an instance."""
   """Config object representing an instance."""

-  __slots__ = [
+  __slots__ = TaggableObject.__slots__ + [

     "name",
     "primary_node",
     "os",
     "name",
     "primary_node",
     "os",

+    "hypervisor",
+    "hvparams",
+    "beparams",

     "status",
     "status",

-    "memory",
-    "vcpus",

     "nics",
     "disks",
     "disk_template",
     "nics",
     "disks",
     "disk_template",

-    "tags",
+    "network_port",
+    "serial_no",

     ]
 
   def _ComputeSecondaryNodes(self):
     ]
 
   def _ComputeSecondaryNodes(self):

@@ -311,8 +526,8 @@ class Instance(ConfigObject, TaggableObject):
     """
     def _Helper(primary, sec_nodes, device):
       """Recursively computes secondary nodes given a top device."""
     """
     def _Helper(primary, sec_nodes, device):
       """Recursively computes secondary nodes given a top device."""

-      if device.dev_type == 'drbd':
-        nodea, nodeb, dummy = device.logical_id
+      if device.dev_type in constants.LDS_DRBD:
+        nodea, nodeb, dummy = device.logical_id[:3]

         if nodea == primary:
           candidate = nodeb
         else:
         if nodea == primary:
           candidate = nodeb
         else:

@@ -360,10 +575,10 @@ class Instance(ConfigObject, TaggableObject):
       devs = self.disks
 
     for dev in devs:
       devs = self.disks
 
     for dev in devs:

-      if dev.dev_type == "lvm":
+      if dev.dev_type == constants.LD_LV:

         lvmap[node].append(dev.logical_id[1])
 
         lvmap[node].append(dev.logical_id[1])
 

-      elif dev.dev_type == "drbd":
+      elif dev.dev_type in constants.LDS_DRBD:

         if dev.logical_id[0] not in lvmap:
           lvmap[dev.logical_id[0]] = []
 
         if dev.logical_id[0] not in lvmap:
           lvmap[dev.logical_id[0]] = []
 

@@ -391,29 +606,81 @@ class Instance(ConfigObject, TaggableObject):
 
     return None
 
 
     return None
 

+  def ToDict(self):
+    """Instance-specific conversion to standard python types.
+
+    This replaces the children lists of objects with lists of standard
+    python types.
+
+    """
+    bo = super(Instance, self).ToDict()
+
+    for attr in "nics", "disks":
+      alist = bo.get(attr, None)
+      if alist:
+        nlist = self._ContainerToDicts(alist)
+      else:
+        nlist = []
+      bo[attr] = nlist
+    return bo
+
+  @classmethod
+  def FromDict(cls, val):
+    """Custom function for instances.
+
+    """
+    obj = super(Instance, cls).FromDict(val)
+    obj.nics = cls._ContainerFromDicts(obj.nics, list, NIC)
+    obj.disks = cls._ContainerFromDicts(obj.disks, list, Disk)
+    return obj
+

 
 class OS(ConfigObject):
   """Config object representing an operating system."""
   __slots__ = [
     "name",
     "path",
 
 class OS(ConfigObject):
   """Config object representing an operating system."""
   __slots__ = [
     "name",
     "path",

-    "api_version",
+    "status",
+    "api_versions",

     "create_script",
     "export_script",
     "import_script",
     "rename_script",
     ]
 
     "create_script",
     "export_script",
     "import_script",
     "rename_script",
     ]
 

+  @classmethod
+  def FromInvalidOS(cls, err):
+    """Create an OS from an InvalidOS error.

 
 

-class Node(ConfigObject, TaggableObject):
+    This routine knows how to convert an InvalidOS error to an OS
+    object representing the broken OS with a meaningful error message.
+
+    """
+    if not isinstance(err, errors.InvalidOS):
+      raise errors.ProgrammerError("Trying to initialize an OS from an"
+                                   " invalid object of type %s" % type(err))
+
+    return cls(name=err.args[0], path=err.args[1], status=err.args[2])
+
+  def __nonzero__(self):
+    return self.status == constants.OS_VALID_STATUS
+
+  __bool__ = __nonzero__
+
+
+class Node(TaggableObject):

   """Config object representing a node."""
   """Config object representing a node."""

-  __slots__ = ["name", "primary_ip", "secondary_ip", "tags"]
+  __slots__ = TaggableObject.__slots__ + [
+    "name",
+    "primary_ip",
+    "secondary_ip",
+    "serial_no",
+    ]

 
 
 
 

-class Cluster(ConfigObject, TaggableObject):
+class Cluster(TaggableObject):

   """Config object representing the cluster."""
   """Config object representing the cluster."""

-  __slots__ = [
-    "config_version",
+  __slots__ = TaggableObject.__slots__ + [

     "serial_no",
     "rsahostkeypub",
     "highest_used_port",
     "serial_no",
     "rsahostkeypub",
     "highest_used_port",

@@ -421,9 +688,77 @@ class Cluster(ConfigObject, TaggableObject):
     "mac_prefix",
     "volume_group_name",
     "default_bridge",
     "mac_prefix",
     "volume_group_name",
     "default_bridge",

-    "tags",
+    "default_hypervisor",
+    "master_node",
+    "master_ip",
+    "master_netdev",
+    "cluster_name",
+    "file_storage_dir",
+    "enabled_hypervisors",
+    "hvparams",
+    "beparams",

     ]
 
     ]
 

+  def ToDict(self):
+    """Custom function for cluster.
+
+    """
+    mydict = super(Cluster, self).ToDict()
+    mydict["tcpudp_port_pool"] = list(self.tcpudp_port_pool)
+    return mydict
+
+  @classmethod
+  def FromDict(cls, val):
+    """Custom function for cluster.
+
+    """
+    obj = super(Cluster, cls).FromDict(val)
+    if not isinstance(obj.tcpudp_port_pool, set):
+      obj.tcpudp_port_pool = set(obj.tcpudp_port_pool)
+    return obj
+
+  @staticmethod
+  def FillDict(defaults_dict, custom_dict):
+    """Basic function to apply settings on top a default dict.
+
+    @type defaults_dict: dict
+    @param defaults_dict: dictionary holding the default values
+    @type custom_dict: dict
+    @param custom_dict: dictionary holding customized value
+    @rtype: dict
+    @return: dict with the 'full' values
+
+    """
+    ret_dict = copy.deepcopy(defaults_dict)
+    ret_dict.update(custom_dict)
+    return ret_dict
+
+  def FillHV(self, instance):
+    """Fill an instance's hvparams dict.
+
+    @type instance: object
+    @param instance: the instance parameter to fill
+    @rtype: dict
+    @return: a copy of the instance's hvparams with missing keys filled from
+        the cluster defaults
+
+    """
+    return self.FillDict(self.hvparams.get(instance.hypervisor, {}),
+                         instance.hvparams)
+
+  def FillBE(self, instance):
+    """Fill an instance's beparams dict.
+
+    @type instance: object
+    @param instance: the instance parameter to fill
+    @rtype: dict
+    @return: a copy of the instance's beparams with missing keys filled from
+        the cluster defaults
+
+    """
+    return self.FillDict(self.beparams.get(constants.BEGR_DEFAULT, {}),
+                         instance.beparams)
+

 
 class SerializableConfigParser(ConfigParser.SafeConfigParser):
   """Simple wrapper over ConfigParse that allows serialization.
 
 class SerializableConfigParser(ConfigParser.SafeConfigParser):
   """Simple wrapper over ConfigParse that allows serialization.