Source code for pywbem_mock._instancewriteprovider

#
# (C) Copyright 2020 InovaDevelopment.com
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
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# 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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# Author: Karl  Schopmeyer <inovadevelopment.com>
#

"""
The :class:`~pywbem_mock.InstanceWriteProvider` class provides the default
implementations of the ``CreateInstance``, ``ModifyInstance`` and
``DeleteInstance`` provider methods by means of
:meth:`~pywbem_mock.InstanceWriteProvider.CreateInstance`,
:meth:`~pywbem_mock.InstanceWriteProvider.ModifyInstance`, and
:meth:`~pywbem_mock.InstanceWriteProvider.DeleteInstance`.

A user-defined instance write provider may implement some or all of these
provider methods. The method descriptions linked above provide a detailed
definition of the input parameters, return values, and required behavior.

The following is a simple example of a user-defined instance write provider
that serves the 'CIM_Foo' and 'CIM_FooFoo' classes and implements
``CreateInstance`` for the purpose of setting a value for the 'InstanceID' key
property:

.. code-block:: python

    import uuid
    from pywbem_mock import InstanceWriteProvider

    class MyInstanceProvider(InstanceWriteProvider):

        # CIM classes served by this provider
        provider_classnames = ['CIM_Foo', 'CIM_FooFoo']

        def CreateInstance(self, namespace, new_instance):
            new_instance.properties["InstanceID"] = \\
                f"{new_instance.classname}.{uuid.uuid4()}"
            return super(MyInstanceProvider, self).CreateInstance(
                namespace, new_instance)

Because the provider in this example does not implement the
``ModifyInstance`` and ``DeleteInstance`` methods, these operations will
use their default implementations from
:class:`~pywbem_mock.InstanceWriteProvider`.

NOTE: Bidirectional association support was added in pywbem version 1.5.
originally the association was visible only in the target namespace for the
CreateInstance so Associations and References only handled reference properties
in that namespace.

This instance provider handles association instances that cross namespaces.
Since the association must be available in all of the namespaces defined by the
reference properties of a new instance (References and Associations requests
can be issued using any of the reference properties in the instance), the
CreateInstance creates the association instance in each namespace defined in a
reference property of the instance (it creates shadow instances of the
association in each namespace defined by a reference property in the
association), ModifyInstance modifies the instance and shadow instances, and
DeleteInstance deletes the instance and shadow instances. References and
Association requests can be executed on instances defined in any namespace
where the association is defined.

These shadow instances are visible in each affected namespaces with the
GetInstance and EnumerateInstance requests.

This is transparent. The association instance is visible in each of the
affected namespaces and References and Associations requests can be issued
using any of the reference properties and the operation source instance.

The provider in this example does not need to implement an ``__init__()``
method, because no additional init parameters are needed.
"""


from pywbem._nocasedict import NocaseDict

from pywbem import CIMInstanceName, CIMInstance, CIMError, CIMClass, \
    CIM_ERR_INVALID_PARAMETER, CIM_ERR_ALREADY_EXISTS, CIM_ERR_INVALID_CLASS, \
    CIM_ERR_NOT_FOUND

from pywbem._utils import _format

from ._baseprovider import BaseProvider

# None of the request method names conform since they are camel case
# pylint: disable=invalid-name

__all__ = ['InstanceWriteProvider']


[docs] class InstanceWriteProvider(BaseProvider): """ This class defines those instance provider methods that may have user-defined providers that override the default provider implementation in this class. *New in pywbem 1.0 as experimental and finalized in 1.2.* User providers are defined by creating a subclass of this class and defining a new provider method for one of the methods in this class with the same signature. Note that user-defined providers may, in turn, call the default providers in this class to complete the CreateInstance, ModifyInstance, or DeleteInstance, in particular for instance providers that dynamically Create or Modify an instance. """ #: :term:`string`: Keyword defining the type of request the provider will #: service. The type for this provider class is predefined as # 'instance-write'. provider_type = 'instance-write' def __init__(self, cimrepository=None): """ Parameters: cimrepository (:class:`~pywbem_mock.BaseRepository` or subclass): The CIM repository to be used by the provider. """ super().__init__(cimrepository)
[docs] def CreateInstance(self, namespace, new_instance): """ Default provider method for :meth:`pywbem.WBEMConnection.CreateInstance`. Create a new CIM instance in the CIM repository of the mock WBEM server. Validation already performed by the provider dispatcher that calls this provider method: - The provider method is called only for the registered class and namespace (only applies to user-defined providers). - The Python types of all input parameters to this provider method are as specified below. - The namespace exists in the CIM repository. - The creation class of the new instance exists in the namespace in the CIM repository. - All properties specified in the new instance are exposed (i.e. defined and inherited with any overrides resolved) by the creation class in the CIM repository, and have the same type-related attributes (i.e. type, is_array, embedded_object). - The creation class of the new instance must not be an abstract class. Validation that should be performed by this provider method: - new_instance does not specify any properties that are not allowed to be initialized by the client, depending on the model implemented by the provider. - new_instance specifies all key properties needed by the provider, depending on the model implemented by the provider. The CIM repository will reject any new instance that does not have all key properties specified. - The new instance (i.e. an instance with the new instance path) does not exist in the CIM repository. This validation needs to be done by the provider because the determination of the key properties for the new instance path may depend on the model implemented by the provider. The CIM repository will reject the creation of instances that already exist, so this check can be delegated to the repository once the new instance path has been determined. - If new_instance is an association, the reference properties must define existing end-point paths to instances or have value None. Parameters: namespace (:term:`string`): The name of the CIM namespace in which the CIM instance is to be created, in any lexical case, and with leading and trailing slash characters removed. new_instance (:class:`~pywbem.CIMInstance`): A representation of the CIM instance to be created. This object is a deep copy of the original client parameter, and may be modified by the provider as needed, before storing it in the CIM repository. The property names in this object have been adjusted to match the lexical case of the property definitions in the creation class of the instance in the CIM repository. The `classname` attribute of this object will specify the creation class for the new instance, in any lexical case. The `properties` attribute of this object will specify the initial property values for the new CIM instance, with property names in any lexical case. Key properties may or may not be included. The `path` attribute of this object will be `None`. The `qualifiers` attribute of this object, if non-empty, should be ignored by the provider, because instance-level qualifiers have been deprecated in CIM. Returns: :class:`~pywbem.CIMInstanceName`: Instance path of the new CIM instance. Raises: :exc:`~pywbem.CIMError`: The provider may raise CIMError with any status code, and typically raises: - CIM_ERR_INVALID_PARAMETER - CIM_ERR_ALREADY_EXISTS """ # Get the creation class with all exposed properties and qualifiers. # Since the existence of the class has already been verified, this # will always succeed. class_store = self.cimrepository.get_class_store(namespace) creation_class = class_store.get(new_instance.classname, copy=False) # Validate association class references have valid end points # paths or None if self.is_association(creation_class): for pn in new_instance: prop = new_instance.properties[pn] if prop.type == 'reference': if prop.value is None: continue # Exception if end point does not exist self.validate_reference_property_endpoint_exists(prop,) # If association class and references multiple namespaces, add instance # to each namespace defined in the reference properties if self.is_association(creation_class): assoc_namespaces = self.find_multins_association_ref_namespaces( new_instance, namespace) if assoc_namespaces: # It is a multi-namespace association instance. Validate # characteristics of other namespaces and insert the same # instance in each of these namespaces with specific path. return self.create_multi_namespace_instance( new_instance, namespace, assoc_namespaces) # Otherwise create a single new instance. # This default provider determines the instance path from the key # properties in the new instance. A user-defined provider may do # that as well, or invent key properties such as InstanceID. # Specifying strict=True in from_instance() verifies that all key # properties exposed by the class are specified in the new instance, # and raises ValueError if key properties are missing. self.create_new_instance_path(creation_class, new_instance, namespace) self.add_new_instance(new_instance) return new_instance.path
[docs] def ModifyInstance(self, modified_instance, IncludeQualifiers=None): # pylint: disable=invalid-name,line-too-long,unused-argument """ Default provider method for :meth:`pywbem.WBEMConnection.CreateInstance`. Modify an existing CIM instance in the CIM repository of the mock WBEM server. NOTE: This method specifies the namespace in modified_instance.path rather than as a separate input parameter. The modification of the instance in the CIM repository that is performed by the provider should be limited to property value changes (including addition of properties if not yet set on the instance), because instance-level qualifiers have been deprecated in CIM. The set of properties that are to be modified in the CIM instance has already been determined by the caller so that the modified_instance parameter specifies exactly the set of properties to be modified. Therefore, this provider method does not have a property list parameter. Validation already performed by the provider dispatcher that calls this provider method: - The provider method is called only for the registered class and namespace (only applies to user-defined providers). - The Python types of all input parameters to this provider method are as specified below. - The classnames in modified_instance are consistent between instance and instance path. - The namespace exists in the CIM repository. - The creation class of the instance to be modified exists in the namespace of the CIM repository. - The instance to be modified exists in the namespace of the CIM repository. - All properties in modified_instance that are to be modified are exposed (i.e. defined and inherited with any overrides resolved) by the creation class in the CIM repository, and have the same type-related attributes (i.e. type, is_array, embedded_object). - No key properties are requested to change their values. - If there was a property list for the request, only properties defined in that property list are included in the modified_instance. Validation that should be performed by this provider method: - modified_instance does not specify any changed values for properties that are not allowed to be changed by the client, depending on the model implemented by the provider. Validation executed for this default provider: - Validate that any reference properties to be modified that are not keys define an association end point instance that currently exists and that the en-point instances exist. - If the association crosses namespaces, validate that the association already exists in all namespaces defined in the reference properties. Parameters: modified_instance (:class:`~pywbem.CIMInstance`): A representation of the modified CIM instance, also indicating its instance path, with exactly the set of properties to be modified. This object is a deep copy of the original client parameter, and may be modified by the provider as needed, before storing it in the CIM repository. The `path` attribute of this object will be set and is the instance path of the instance to be modified in the CIM repository. Its `namespace`, `classname` and `keybindings` attributes will be set. The names will be in any lexical case. The `classname` attribute of this object will specify the creation class of the instance to be modified, in any lexical case. The `properties` attribute of this object will specify exactly the set of properties that are to be updated, taking into account the original ModifiedInstance and PropertyList input parameters of the ModifyInstance() client call. The lexical case of the property names has been adjusted to match the lexical cae of the property definitions in the creation class in the CIM repository. The `qualifiers` attribute of this object, if non-empty, should be ignored by the provider, because instance-level qualifiers have been deprecated in CIM. IncludeQualifiers (:class:`py:bool`): This parameter should be ignored by the provider, because instance-level qualifiers have been deprecated in CIM. Raises: :exc:`~pywbem.CIMError`: The provider may raise CIMError with any status code, and typically raises: - CIM_ERR_INVALID_PARAMETER """ # noqa: E501 # pylint: disable=invalid-name,line-too-long namespace = modified_instance.path.namespace # Get a copy of the instance to be modified from the CIM repository. instance_store = self.cimrepository.get_instance_store(namespace) # Copied because this will be used as the instance to update. original_instance = instance_store.get(modified_instance.path) # Get class defined for modified instance. class_store = self.cimrepository.get_class_store(namespace) creation_class = class_store.get(modified_instance.classname, copy=False) # Test for modified reference properties and validate if corresponding # instances exist. This is behavior for this default provider. # A specific provider may behave differently, ex. ignore non-existend # end-point instances if self.is_association(creation_class): for pn in modified_instance: prop = modified_instance.properties[pn] if prop.type == 'reference': # Do not allow setting ref property value to None. Would # mean significant extra work removing shadow instances if prop.value is None: raise CIMError( CIM_ERR_INVALID_PARAMETER, _format("Reference property {0!A} association " "end {1!A} with None value not allowed ", prop.name, prop.value)) if prop.value != original_instance[pn]: self.validate_reference_property_endpoint_exists(prop,) # Update the properties in the original instance from properties # in the modified instance original_instance.update(modified_instance.properties) # Note: IncludeQualifiers is completely ignored per DMTF spec. # If association class and reference properties define multiple # namespaces, modify instance in each namespace defined in the # instance. if self.is_association(creation_class): assoc_namespaces = self.find_multins_association_ref_namespaces( original_instance, namespace) if assoc_namespaces: # It is a multi-namespace association instance. Validate # characteristics of other namespaces and insert the same # instance in each of these namespaces with specific path. self.modify_multi_namespace_instance( original_instance, assoc_namespaces) return # Replace the instance in the CIM repository with the local copy. instance_store.update(original_instance.path, original_instance)
[docs] def DeleteInstance(self, InstanceName): """ Default provider method for :meth:`pywbem.WBEMConnection.DeleteInstance`. Delete an existing instance in the CIM repository of the mock WBEM server. NOTE: This method specifies the namespace in InstanceName rather than as a separate input parameter. The provider is not responsible for determining other instances that depend on the instance to be deleted (e.g. association instances referencing the instance to be deleted); such dependency detection and handling is done elsewhere. Validation already performed by the provider dispatcher that calls this provider method: - The provider method is called only for the registered class and namespace (only applies to user-defined providers). - The Python types of all input parameters to this provider method are as specified below. - The namespace exists in the CIM repository. - The creation class of the instance to be deleted exists in the namespace of the CIM repository. - The instance to be deleted exists in the namespace of the CIM repository. Parameters: InstanceName (:class:`~pywbem.CIMInstanceName`): The instance path of the instance to be deleted with the following attributes: * `classname`: Name of the creation class of the instance. * `keybindings`: Keybindings of the instance. * `namespace`: Name of the CIM namespace containing the instance. Will not be `None`. * `host`: Will be `None`. """ namespace = InstanceName.namespace class_store = self.cimrepository.get_class_store(namespace) creation_class = class_store.get(InstanceName.classname, copy=False) if not self.is_association(creation_class): # Delete the instance from the CIM repository instance_store = self.cimrepository.get_instance_store(namespace) instance_store.delete(InstanceName) else: multi_ns = self.find_multins_association_ref_namespaces( InstanceName, namespace) if multi_ns: multi_ns.append(namespace) instance_name_copy = InstanceName.copy() for ns in multi_ns: instance_name_copy.namespace = ns instance_store = self.cimrepository.get_instance_store(ns) instance_store.delete(instance_name_copy) else: instance_store = \ self.cimrepository.get_instance_store(namespace) instance_store.delete(InstanceName)
[docs] def post_register_setup(self, conn): """ Method called by provider registration after registation of provider is successful. Using this method is optional for registration cases where the provider must execute some activity (ex. modify the CIM repository) after successful provider registration). Override this method in the user-defined provider subclass to execute this method. Parameters: conn (:class:`~pywbem.WBEMConnection`): Current connection which allows client methods to be executed from within this method. """
##################################################################### # # Support methods. The following methods are support for the # Create/Modify/Delete instance default implementations above. # They are shown as public because they an be useful in building # alternates to the this default Create/Modify/Delete instance # implementation. # #####################################################################
[docs] def find_multins_association_ref_namespaces(self, cim_object, target_namespace): # pylint: disable=line-too-long """ Return list of namespaces in which this association participates excluding the target namespace. If an empty list is returned, this is not a multi-namespace association. Parameters: cim_object (:class:`~pywbem.CIMInstance` or :class:`~pywbem.CIMInstanceName`): # noqa: E501 Object from which references/keybindings searched to determine if multinamespace object. Must be an association. target_namespace (:term:`string`): The namespace name provided with the request call (ex. CreateInstance) Returns: List of namespace names of namespaces in which this association instance participates if there are multiple namespaces. If no other namespaces are defined by reference properties, it returns None. """ # pylint: enable=line-too-long if isinstance(cim_object, CIMInstanceName): instance_store = self.cimrepository.get_instance_store( target_namespace) cim_object = instance_store.get(cim_object, copy=False) assert isinstance(cim_object, CIMInstance) creation_class = self.get_required_class(cim_object, target_namespace) assert self.is_association(creation_class) ref_namespaces = set() for inst_prop in cim_object.properties.values(): if inst_prop.type == 'reference': refprop_namespace = inst_prop.value.namespace assert refprop_namespace is not None, \ _format("Invalid namespace value None found in reference " "property: {0|A}", inst_prop.value) # Add to list if namespace exists and not same as # target_namespace if refprop_namespace: if refprop_namespace != target_namespace: ref_namespaces.add(inst_prop.value.namespace) return list(ref_namespaces)
[docs] def get_required_class(self, instance, namespace): """ Get the class defined by instance.classname from the repository. This is the common method to validate the class for create instance. If the class does not exist, generate a CIMError. """ class_store = self.cimrepository.get_class_store(namespace) try: return class_store.get(instance.classname) except KeyError: raise CIMError( CIM_ERR_INVALID_CLASS, _format("Creation class {0!A} of new multi-namespace " "association instance does not " "exist in namespace {1!A} of the CIM repository.", instance.classname, namespace))
[docs] @staticmethod def is_association(klass): """ Test if klass is an association class. Return True if klass is an association class and value is True. If association qualifier exists but is False or does not exist return False. """ assert isinstance(klass, CIMClass) return klass.qualifiers.get('Association', False)
[docs] def create_multi_namespace_instance(self, new_instance, orig_ns, assoc_namespaces): """ Creates an instance of association new_instance in each namespace defined by reference properties of the association instance where the namespace in the reference property is not the namespace defined with the create instance call. Each instance is the same as the original instance except that each has its own namespace definition in the CIMInstanceName and the reference properties differ if any reference property does not include the namespace in its definition. Confirm that this is a multi-namespace association instance, that the class exists in all namespaces. If these tests are OK, confirm that the instance does not exist in any other namespace. Then, place the instance in the remote namespaces Any case where the instances cannot be created for all required namespaces causes an exception. Parameters: new_instance (:class:`~pywbem.CIMInstance`): The new instance that will be created orig_ns (:term:`string`): The namespace name attached to the CreateInstance request assoc_namespaces (list of :term:`string`): List of the namespaces defined in reference properties including the original namespace (orig_ns) Returns: If the instance is created, the CIM_InstanceName for the created instance is returned. Asserts: CIMError if error occurs in validity of other namespaces, class in other namespaces, or creating of instance in other namespaces. """ # Add the original namespace to the list. assoc_namespaces.append(orig_ns) # Validate that the class exists in all of the namespaces. It was # already tested for existence in the namespace defined with the # create. for ns in assoc_namespaces: # Verify that the class exists in the namespace creation_class = self.get_required_class(new_instance, ns) # Class exists in all target namespaces. Confirm instances are correct. new_instance_paths = {} for ns in assoc_namespaces: # Set new path in the instance for namespace ns # This is the default behavior. A provider may chose to # define the path otherwise since it may also be building the # instance to be created dynamically. # FUTURE: How do we handle that or should we require that this is # the only multi-ns method. try: inst_path = CIMInstanceName.from_instance( creation_class, new_instance, namespace=ns, strict=True) new_instance_paths[ns] = inst_path except ValueError as exc: raise CIMError(CIM_ERR_INVALID_PARAMETER, str(exc)) # Confirm the new instance does not exist in any of the namespaces. for ns, path in new_instance_paths.items(): instance_store = self.cimrepository.get_instance_store(ns) if instance_store.object_exists(path): raise CIMError( CIM_ERR_ALREADY_EXISTS, _format("New instance {0!A} already exists in namespace " "{1!A}. Cannot create new instance.", path, ns)) # Add the new instance with path for each ns to each of the namespaces. for ns, path in new_instance_paths.items(): instance_store = self.cimrepository.get_instance_store(ns) new_instance.path = path self.add_new_instance(new_instance) return new_instance_paths[orig_ns]
[docs] def add_new_instance(self, new_instance): """ Add the new instance to the repository. If the instance already exists raises CIMError exception """ namespace = new_instance.path.namespace # Get the instance store of the CIM repository. Since the existence of # the namespace has already been verified, this will always succeed. instance_store = self.cimrepository.get_instance_store(namespace) # Store the new instance in the CIM repository, verifying that it does # not exist yet. # NOTE: This is where we have invalid repository issue try: instance_store.create(new_instance.path, new_instance) except ValueError: raise CIMError( CIM_ERR_ALREADY_EXISTS, _format("New instance {0!A} already exists in namespace " "{1!A}.", new_instance.path, namespace))
[docs] def modify_multi_namespace_instance(self, modified_instance, assoc_namespaces): """ Modifies the instance of association modified_instance in each namespace defined by reference properties of the association instance where the namespace in the reference property is not the namespace defined with the create instance call. The instances are the same except the instance path contains the namespace in which the instance exists. Any case where the instances cannot be modified for all required namespaces causes an exception. Parameters: modified_instance (:class:`~pywbem.CIMInstance`): The modified instance that is to replace the original instance in the repository assoc_namespaces (list of :term:`string`): List of the namespaces defined in reference properties including the original namespace (orig_ns) Returns: If the instance is created, the CIM_InstanceName for the created instance is returned. Asserts: CIMError if error occurs in validity of other namespaces, class in other namespaces, or creating of instance in other namespaces. """ # Add the original namespace as the last in list. assoc_namespaces.append(modified_instance.path.namespace) # Validate that the class exists in all of the namespaces. It was # already tested for existence in the namespace defined with the # create. for ns in assoc_namespaces: # Verify that the class exists in the namespace _ = self.get_required_class(modified_instance, ns) # Confirm instances are correct and build dict of instance names for # all the assoc intance names modified_instance_paths = NocaseDict() # used to keep dict order for ns in assoc_namespaces: # Set new path in the instance for namespace ns modified_path = modified_instance.copy().path modified_path.namespace = ns modified_instance_paths[ns] = modified_path # Confirm the modified instance exists in all of the namespaces. for ns, path in modified_instance_paths.items(): instance_store = self.cimrepository.get_instance_store(ns) if not instance_store.object_exists(path): raise CIMError( CIM_ERR_NOT_FOUND, _format("Modified instance {0!A} does not exist in " "namespace {1!A}. Modify Failed", path, ns)) # Modify the instance path for each namespace for ns, path in modified_instance_paths.items(): instance_store = self.cimrepository.get_instance_store(ns) modified_instance.path = path instance_store.update(modified_instance.path, modified_instance)
[docs] @staticmethod def create_new_instance_path(creation_class, new_instance, namespace): """ Create the path for the new instance and insert it into the new_instance.path. This default provider determines the instance path from the key properties in the new instance. A user-defined provider may do that as well, or invent key properties such as InstanceID. Specifying strict=True from_instance() verifies that all key properties exposed by the class are specified in the new instance, and raises ValueError if key properties are missing. Parameters: creation_class (:class:`~pywbem.CIMClass`): The CIM class from which the instance was created. Used to determine the key properties. new_instance (:class:`~pywbem.CIMInstance`): The instance from which the CIMInstanceName will be derived. namespace: (:term:`string`): The namespace in which the instance will be added. Raises: :exc:`~pywbem.CIMError`: if instance name cannot be created from instance. """ try: new_instance.path = CIMInstanceName.from_instance( creation_class, new_instance, namespace=namespace, strict=True) except ValueError as exc: raise CIMError(CIM_ERR_INVALID_PARAMETER, str(exc))
[docs] def validate_instance_exists(self, path): """ Confirm that the path defined by the path exists in the namespace defined for that path. Null value for path allowed (i.e. no path defined). Returns True if the object exists or the path is empty otherwise False. Parameters: path (:class:`~pywbem.CIMInstanceName`): path to instance to be tested including namespace. Returns: True if path exists in instance store or path is Null. False if path exists and is not in instance store. """ if not path: return True try: inst_store = self.cimrepository.get_instance_store(path.namespace) except KeyError as ke: raise CIMError(CIM_ERR_INVALID_PARAMETER, str(ke)) return inst_store.object_exists(path)
[docs] def validate_reference_property_endpoint_exists(self, prop): """ Validate that the path defined for the reference property prop exists. Generates INVALID_PARAMETER if it does not exist. Parameters: prop (:class:`~pywbem.CIMInstanceName`): Reference property containing CIMInstanceName as value or Null value. Raises: :exc:`~pywbem.CIMError`: If value of property is not a valid instance or Null. """ path = prop.value if path.host: raise CIMError( CIM_ERR_INVALID_PARAMETER, _format("Reference property {0!A} association " "end point {1!A} includes host element {2!A}. " "Pywbem_mock does not allow host element in " "reference properties of association instances", prop.name, path, path.host)) if not self.validate_instance_exists(path): raise CIMError( CIM_ERR_INVALID_PARAMETER, _format("Reference property {0!A} association " "end point {1!A} does not exist ", prop.name, path))