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Posted to dev@ariatosca.apache.org by mx...@apache.org on 2017/06/06 12:20:19 UTC

[2/2] incubator-ariatosca git commit: ARIA-262 Inconsistent node attributes behavior

ARIA-262 Inconsistent node attributes behavior

Inroduced a more comprehensive way to instrument relationship attributes.

Old behavior instrumented attributes only if they were accessed directly from the
parent model. Traversing the storage made the access to an attribute inconsistent.

The new solution enables encapsulating the attributes disregarding the way they
were retrieved.


Project: http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/commit/180e0a1c
Tree: http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/tree/180e0a1c
Diff: http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/diff/180e0a1c

Branch: refs/heads/ARIA-262-Inconsistent-node-attributes-behavior
Commit: 180e0a1cf1ad6da0ddd611b90a58e71acbea52e7
Parents: e4d0036
Author: max-orlov <ma...@gigaspaces.com>
Authored: Wed May 31 21:07:49 2017 +0300
Committer: max-orlov <ma...@gigaspaces.com>
Committed: Tue Jun 6 15:20:12 2017 +0300

----------------------------------------------------------------------
 .../context/collection_instrumentation.py       | 242 ---------------
 aria/orchestrator/context/operation.py          |  21 +-
 aria/orchestrator/context/toolbelt.py           |   6 +-
 aria/orchestrator/decorators.py                 |   6 +-
 .../execution_plugin/ctx_proxy/server.py        |  17 +-
 aria/storage/api.py                             |  10 +
 aria/storage/collection_instrumentation.py      | 306 +++++++++++++++++++
 aria/storage/core.py                            |  15 +
 aria/storage/sql_mapi.py                        |  14 +-
 aria/utils/imports.py                           |   2 +-
 .../context/test_collection_instrumentation.py  | 150 ++++++---
 .../execution_plugin/test_ctx_proxy_server.py   |   2 +-
 tests/orchestrator/execution_plugin/test_ssh.py |  10 +-
 tests/orchestrator/workflows/core/test_task.py  |   2 +-
 .../executor/test_process_executor_extension.py |   3 +-
 15 files changed, 490 insertions(+), 316 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/orchestrator/context/collection_instrumentation.py
----------------------------------------------------------------------
diff --git a/aria/orchestrator/context/collection_instrumentation.py b/aria/orchestrator/context/collection_instrumentation.py
deleted file mode 100644
index 8f80d4a..0000000
--- a/aria/orchestrator/context/collection_instrumentation.py
+++ /dev/null
@@ -1,242 +0,0 @@
-# Licensed to the Apache Software Foundation (ASF) under one or more
-# contributor license agreements.  See the NOTICE file distributed with
-# this work for additional information regarding copyright ownership.
-# The ASF licenses this file to You under the Apache License, Version 2.0
-# (the "License"); you may not use this file except in compliance with
-# the License.  You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-from functools import partial
-
-from aria.modeling import models
-
-
-class _InstrumentedCollection(object):
-
-    def __init__(self,
-                 model,
-                 parent,
-                 field_name,
-                 seq=None,
-                 is_top_level=True,
-                 **kwargs):
-        self._model = model
-        self._parent = parent
-        self._field_name = field_name
-        self._is_top_level = is_top_level
-        self._load(seq, **kwargs)
-
-    @property
-    def _raw(self):
-        raise NotImplementedError
-
-    def _load(self, seq, **kwargs):
-        """
-        Instantiates the object from existing seq.
-
-        :param seq: the original sequence to load from
-        :return:
-        """
-        raise NotImplementedError
-
-    def _set(self, key, value):
-        """
-        set the changes for the current object (not in the db)
-
-        :param key:
-        :param value:
-        :return:
-        """
-        raise NotImplementedError
-
-    def _del(self, collection, key):
-        raise NotImplementedError
-
-    def _instrument(self, key, value):
-        """
-        Instruments any collection to track changes (and ease of access)
-        :param key:
-        :param value:
-        :return:
-        """
-        if isinstance(value, _InstrumentedCollection):
-            return value
-        elif isinstance(value, dict):
-            instrumentation_cls = _InstrumentedDict
-        elif isinstance(value, list):
-            instrumentation_cls = _InstrumentedList
-        else:
-            return value
-
-        return instrumentation_cls(self._model, self, key, value, False)
-
-    @staticmethod
-    def _raw_value(value):
-        """
-        Get the raw value.
-        :param value:
-        :return:
-        """
-        if isinstance(value, models.Attribute):
-            return value.value
-        return value
-
-    @staticmethod
-    def _encapsulate_value(key, value):
-        """
-        Create a new item cls if needed.
-        :param key:
-        :param value:
-        :return:
-        """
-        if isinstance(value, models.Attribute):
-            return value
-        # If it is not wrapped
-        return models.Attribute.wrap(key, value)
-
-    def __setitem__(self, key, value):
-        """
-        Update the values in both the local and the db locations.
-        :param key:
-        :param value:
-        :return:
-        """
-        self._set(key, value)
-        if self._is_top_level:
-            # We are at the top level
-            field = getattr(self._parent, self._field_name)
-            mapi = getattr(self._model, models.Attribute.__modelname__)
-            value = self._set_field(field,
-                                    key,
-                                    value if key in field else self._encapsulate_value(key, value))
-            mapi.update(value)
-        else:
-            # We are not at the top level
-            self._set_field(self._parent, self._field_name, self)
-
-    def _set_field(self, collection, key, value):
-        """
-        enables updating the current change in the ancestors
-        :param collection: the collection to change
-        :param key: the key for the specific field
-        :param value: the new value
-        :return:
-        """
-        if isinstance(value, _InstrumentedCollection):
-            value = value._raw
-        if key in collection and isinstance(collection[key], models.Attribute):
-            if isinstance(collection[key], _InstrumentedCollection):
-                self._del(collection, key)
-            collection[key].value = value
-        else:
-            collection[key] = value
-        return collection[key]
-
-    def __deepcopy__(self, *args, **kwargs):
-        return self._raw
-
-
-class _InstrumentedDict(_InstrumentedCollection, dict):
-
-    def _load(self, dict_=None, **kwargs):
-        dict.__init__(
-            self,
-            tuple((key, self._raw_value(value)) for key, value in (dict_ or {}).items()),
-            **kwargs)
-
-    def update(self, dict_=None, **kwargs):
-        dict_ = dict_ or {}
-        for key, value in dict_.items():
-            self[key] = value
-        for key, value in kwargs.items():
-            self[key] = value
-
-    def __getitem__(self, key):
-        return self._instrument(key, dict.__getitem__(self, key))
-
-    def _set(self, key, value):
-        dict.__setitem__(self, key, self._raw_value(value))
-
-    @property
-    def _raw(self):
-        return dict(self)
-
-    def _del(self, collection, key):
-        del collection[key]
-
-
-class _InstrumentedList(_InstrumentedCollection, list):
-
-    def _load(self, list_=None, **kwargs):
-        list.__init__(self, list(item for item in list_ or []))
-
-    def append(self, value):
-        self.insert(len(self), value)
-
-    def insert(self, index, value):
-        list.insert(self, index, self._raw_value(value))
-        if self._is_top_level:
-            field = getattr(self._parent, self._field_name)
-            field.insert(index, self._encapsulate_value(index, value))
-        else:
-            self._parent[self._field_name] = self
-
-    def __getitem__(self, key):
-        return self._instrument(key, list.__getitem__(self, key))
-
-    def _set(self, key, value):
-        list.__setitem__(self, key, value)
-
-    def _del(self, collection, key):
-        del collection[key]
-
-    @property
-    def _raw(self):
-        return list(self)
-
-
-class _InstrumentedModel(object):
-
-    def __init__(self, field_name, original_model, model_storage):
-        super(_InstrumentedModel, self).__init__()
-        self._field_name = field_name
-        self._model_storage = model_storage
-        self._original_model = original_model
-        self._apply_instrumentation()
-
-    def __getattr__(self, item):
-        return getattr(self._original_model, item)
-
-    def _apply_instrumentation(self):
-
-        field = getattr(self._original_model, self._field_name)
-
-        # Preserve the original value. e.g. original attributes would be located under
-        # _attributes
-        setattr(self, '_{0}'.format(self._field_name), field)
-
-        # set instrumented value
-        setattr(self, self._field_name, _InstrumentedDict(self._model_storage,
-                                                          self._original_model,
-                                                          self._field_name,
-                                                          field))
-
-
-def instrument_collection(field_name, func=None):
-    if func is None:
-        return partial(instrument_collection, field_name)
-
-    def _wrapper(*args, **kwargs):
-        original_model = func(*args, **kwargs)
-        return type('Instrumented{0}'.format(original_model.__class__.__name__),
-                    (_InstrumentedModel, ),
-                    {})(field_name, original_model, args[0].model)
-
-    return _wrapper

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/orchestrator/context/operation.py
----------------------------------------------------------------------
diff --git a/aria/orchestrator/context/operation.py b/aria/orchestrator/context/operation.py
index f0ba337..af7220d 100644
--- a/aria/orchestrator/context/operation.py
+++ b/aria/orchestrator/context/operation.py
@@ -21,10 +21,7 @@ import threading
 
 import aria
 from aria.utils import file
-from . import (
-    common,
-    collection_instrumentation
-)
+from . import common
 
 
 class BaseOperationContext(common.BaseContext):
@@ -32,6 +29,13 @@ class BaseOperationContext(common.BaseContext):
     Context object used during operation creation and execution
     """
 
+    INSTRUMENTATION_FIELDS = (
+        aria.modeling.models.Node.attributes,
+        aria.modeling.models.Node.properties,
+        aria.modeling.models.NodeTemplate.attributes,
+        aria.modeling.models.NodeTemplate.properties
+    )
+
     def __init__(self, task_id, actor_id, **kwargs):
         self._task_id = task_id
         self._actor_id = actor_id
@@ -76,7 +80,6 @@ class BaseOperationContext(common.BaseContext):
 
     @property
     def serialization_dict(self):
-        context_cls = self.__class__
         context_dict = {
             'name': self.name,
             'service_id': self._service_id,
@@ -89,7 +92,7 @@ class BaseOperationContext(common.BaseContext):
             'logger_level': self.logger.level
         }
         return {
-            'context_cls': context_cls,
+            'context_cls': self.__class__,
             'context': context_dict
         }
 
@@ -117,7 +120,6 @@ class NodeOperationContext(BaseOperationContext):
     """
 
     @property
-    @collection_instrumentation.instrument_collection('attributes')
     def node_template(self):
         """
         the node of the current operation
@@ -126,7 +128,6 @@ class NodeOperationContext(BaseOperationContext):
         return self.node.node_template
 
     @property
-    @collection_instrumentation.instrument_collection('attributes')
     def node(self):
         """
         The node instance of the current operation
@@ -141,7 +142,6 @@ class RelationshipOperationContext(BaseOperationContext):
     """
 
     @property
-    @collection_instrumentation.instrument_collection('attributes')
     def source_node_template(self):
         """
         The source node
@@ -150,7 +150,6 @@ class RelationshipOperationContext(BaseOperationContext):
         return self.source_node.node_template
 
     @property
-    @collection_instrumentation.instrument_collection('attributes')
     def source_node(self):
         """
         The source node instance
@@ -159,7 +158,6 @@ class RelationshipOperationContext(BaseOperationContext):
         return self.relationship.source_node
 
     @property
-    @collection_instrumentation.instrument_collection('attributes')
     def target_node_template(self):
         """
         The target node
@@ -168,7 +166,6 @@ class RelationshipOperationContext(BaseOperationContext):
         return self.target_node.node_template
 
     @property
-    @collection_instrumentation.instrument_collection('attributes')
     def target_node(self):
         """
         The target node instance

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/orchestrator/context/toolbelt.py
----------------------------------------------------------------------
diff --git a/aria/orchestrator/context/toolbelt.py b/aria/orchestrator/context/toolbelt.py
index 5788ee7..b5a54a9 100644
--- a/aria/orchestrator/context/toolbelt.py
+++ b/aria/orchestrator/context/toolbelt.py
@@ -33,11 +33,7 @@ class NodeToolBelt(object):
         :return:
         """
         assert isinstance(self._op_context, operation.NodeOperationContext)
-        host = self._op_context.node.host
-        ip = host.attributes.get('ip')
-        if ip:
-            return ip.value
-
+        return self._op_context.node.host.attributes.get('ip')
 
 
 class RelationshipToolBelt(object):

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/orchestrator/decorators.py
----------------------------------------------------------------------
diff --git a/aria/orchestrator/decorators.py b/aria/orchestrator/decorators.py
index 4051a54..80f6962 100644
--- a/aria/orchestrator/decorators.py
+++ b/aria/orchestrator/decorators.py
@@ -68,11 +68,13 @@ def operation(func=None, toolbelt=False, suffix_template='', logging_handlers=No
 
     @wraps(func)
     def _wrapper(**func_kwargs):
+        ctx = func_kwargs['ctx']
         if toolbelt:
-            operation_toolbelt = context.toolbelt(func_kwargs['ctx'])
+            operation_toolbelt = context.toolbelt(ctx)
             func_kwargs.setdefault('toolbelt', operation_toolbelt)
         validate_function_arguments(func, func_kwargs)
-        return func(**func_kwargs)
+        with ctx.model.instrument(*ctx.INSTRUMENTATION_FIELDS):
+            return func(**func_kwargs)
     return _wrapper
 
 

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/orchestrator/execution_plugin/ctx_proxy/server.py
----------------------------------------------------------------------
diff --git a/aria/orchestrator/execution_plugin/ctx_proxy/server.py b/aria/orchestrator/execution_plugin/ctx_proxy/server.py
index 102ff9a..50d4c3a 100644
--- a/aria/orchestrator/execution_plugin/ctx_proxy/server.py
+++ b/aria/orchestrator/execution_plugin/ctx_proxy/server.py
@@ -117,14 +117,15 @@ class CtxProxy(object):
 
     def _process(self, request):
         try:
-            typed_request = json.loads(request)
-            args = typed_request['args']
-            payload = _process_ctx_request(self.ctx, args)
-            result_type = 'result'
-            if isinstance(payload, exceptions.ScriptException):
-                payload = dict(message=str(payload))
-                result_type = 'stop_operation'
-            result = {'type': result_type, 'payload': payload}
+            with self.ctx.model.instrument(*self.ctx.INSTRUMENTATION_FIELDS):
+                typed_request = json.loads(request)
+                args = typed_request['args']
+                payload = _process_ctx_request(self.ctx, args)
+                result_type = 'result'
+                if isinstance(payload, exceptions.ScriptException):
+                    payload = dict(message=str(payload))
+                    result_type = 'stop_operation'
+                result = {'type': result_type, 'payload': payload}
         except Exception as e:
             traceback_out = StringIO.StringIO()
             traceback.print_exc(file=traceback_out)

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/storage/api.py
----------------------------------------------------------------------
diff --git a/aria/storage/api.py b/aria/storage/api.py
index ed8a2ff..3304721 100644
--- a/aria/storage/api.py
+++ b/aria/storage/api.py
@@ -15,6 +15,7 @@
 """
 General storage API
 """
+import threading
 
 
 class StorageAPI(object):
@@ -45,6 +46,15 @@ class ModelAPI(StorageAPI):
         super(ModelAPI, self).__init__(**kwargs)
         self._model_cls = model_cls
         self._name = name or model_cls.__modelname__
+        self._thread_local = threading.local()
+        self._thread_local._instrumentation = []
+
+    @property
+    def _instrumentation(self):
+        if not hasattr(self._thread_local, '_instrumentation'):
+            self._thread_local._instrumentation = []
+        return self._thread_local._instrumentation
+
 
     @property
     def name(self):

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/storage/collection_instrumentation.py
----------------------------------------------------------------------
diff --git a/aria/storage/collection_instrumentation.py b/aria/storage/collection_instrumentation.py
new file mode 100644
index 0000000..27d8322
--- /dev/null
+++ b/aria/storage/collection_instrumentation.py
@@ -0,0 +1,306 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import exceptions
+
+
+class _InstrumentedCollection(object):
+
+    def __init__(self,
+                 mapi,
+                 parent,
+                 field_name,
+                 field_cls,
+                 seq=None,
+                 is_top_level=True,
+                 **kwargs):
+        self._mapi = mapi
+        self._parent = parent
+        self._field_name = field_name
+        self._is_top_level = is_top_level
+        self._field_cls = field_cls
+        self._load(seq, **kwargs)
+
+    @property
+    def _raw(self):
+        raise NotImplementedError
+
+    def _load(self, seq, **kwargs):
+        """
+        Instantiates the object from existing seq.
+
+        :param seq: the original sequence to load from
+        :return:
+        """
+        raise NotImplementedError
+
+    def _set(self, key, value):
+        """
+        set the changes for the current object (not in the db)
+
+        :param key:
+        :param value:
+        :return:
+        """
+        raise NotImplementedError
+
+    def _del(self, collection, key):
+        raise NotImplementedError
+
+    def _instrument(self, key, value):
+        """
+        Instruments any collection to track changes (and ease of access)
+        :param key:
+        :param value:
+        :return:
+        """
+        if isinstance(value, _InstrumentedCollection):
+            return value
+        elif isinstance(value, dict):
+            instrumentation_cls = _InstrumentedDict
+        elif isinstance(value, list):
+            instrumentation_cls = _InstrumentedList
+        else:
+            return value
+
+        return instrumentation_cls(self._mapi, self, key, self._field_cls, value, False)
+
+    def _raw_value(self, value):
+        """
+        Get the raw value.
+        :param value:
+        :return:
+        """
+        if isinstance(value, self._field_cls):
+            return value.value
+        return value
+
+    def _encapsulate_value(self, key, value):
+        """
+        Create a new item cls if needed.
+        :param key:
+        :param value:
+        :return:
+        """
+        if isinstance(value, self._field_cls):
+            return value
+        # If it is not wrapped
+        return self._field_cls.wrap(key, value)
+
+    def __setitem__(self, key, value):
+        """
+        Update the values in both the local and the db locations.
+        :param key:
+        :param value:
+        :return:
+        """
+        self._set(key, value)
+        if self._is_top_level:
+            # We are at the top level
+            field = getattr(self._parent, self._field_name)
+            self._set_field(
+                field, key, value if key in field else self._encapsulate_value(key, value))
+            self._mapi.update(self._parent)
+        else:
+            # We are not at the top level
+            self._set_field(self._parent, self._field_name, self)
+
+    def _set_field(self, collection, key, value):
+        """
+        enables updating the current change in the ancestors
+        :param collection: the collection to change
+        :param key: the key for the specific field
+        :param value: the new value
+        :return:
+        """
+        if isinstance(value, _InstrumentedCollection):
+            value = value._raw
+        if key in collection and isinstance(collection[key], self._field_cls):
+            if isinstance(collection[key], _InstrumentedCollection):
+                self._del(collection, key)
+            collection[key].value = value
+        else:
+            collection[key] = value
+        return collection[key]
+
+    def __deepcopy__(self, *args, **kwargs):
+        return self._raw
+
+
+class _InstrumentedDict(_InstrumentedCollection, dict):
+
+    def _load(self, dict_=None, **kwargs):
+        dict.__init__(
+            self,
+            tuple((key, self._raw_value(value)) for key, value in (dict_ or {}).items()),
+            **kwargs)
+
+    def update(self, dict_=None, **kwargs):
+        dict_ = dict_ or {}
+        for key, value in dict_.items():
+            self[key] = value
+        for key, value in kwargs.items():
+            self[key] = value
+
+    def __getitem__(self, key):
+        return self._instrument(key, dict.__getitem__(self, key))
+
+    def _set(self, key, value):
+        dict.__setitem__(self, key, self._raw_value(value))
+
+    @property
+    def _raw(self):
+        return dict(self)
+
+    def _del(self, collection, key):
+        del collection[key]
+
+
+class _InstrumentedList(_InstrumentedCollection, list):
+
+    def _load(self, list_=None, **kwargs):
+        list.__init__(self, list(item for item in list_ or []))
+
+    def append(self, value):
+        self.insert(len(self), value)
+
+    def insert(self, index, value):
+        list.insert(self, index, self._raw_value(value))
+        if self._is_top_level:
+            field = getattr(self._parent, self._field_name)
+            field.insert(index, self._encapsulate_value(index, value))
+        else:
+            self._parent[self._field_name] = self
+
+    def __getitem__(self, key):
+        return self._instrument(key, list.__getitem__(self, key))
+
+    def _set(self, key, value):
+        list.__setitem__(self, key, value)
+
+    def _del(self, collection, key):
+        del collection[key]
+
+    @property
+    def _raw(self):
+        return list(self)
+
+
+class _InstrumentedModel(object):
+
+    def __init__(self, original_model, mapi, instrumentation):
+        """
+        The original model
+        :param original_model: the model to be instrumented
+        :param mapi: the mapi for that model
+        """
+        super(_InstrumentedModel, self).__init__()
+        self._original_model = original_model
+        self._mapi = mapi
+        self._instrumentation = instrumentation
+        self._apply_instrumentation()
+
+    def __getattr__(self, item):
+        return_value = getattr(self._original_model, item)
+        if isinstance(return_value, self._original_model.__class__):
+            return _create_instrumented_model(return_value, self._mapi, self._instrumentation)
+        if isinstance(return_value, (list, dict)):
+            return _create_wrapped_model(return_value, self._mapi, self._instrumentation)
+        return return_value
+
+    def _apply_instrumentation(self):
+        for field in self._instrumentation:
+            field_name = field.key
+            field_cls = field.mapper.class_
+            field = getattr(self._original_model, field_name)
+
+            # Preserve the original value. e.g. original attributes would be located under
+            # _attributes
+            setattr(self, '_{0}'.format(field_name), field)
+
+            # set instrumented value
+            if isinstance(field, dict):
+                instrumentation_cls = _InstrumentedDict
+            elif isinstance(field, list):
+                instrumentation_cls = _InstrumentedList
+            else:
+                # TODO: raise proper error
+                raise exceptions.StorageError(
+                    "ARIA supports instrumentation for dict and list. Field {field} of the "
+                    "class {model} is of {type} type.".format(
+                        field=field,
+                        model=self._original_model,
+                        type=type(field)))
+
+            instrumented_class = instrumentation_cls(seq=field,
+                                                     parent=self._original_model,
+                                                     mapi=self._mapi,
+                                                     field_name=field_name,
+                                                     field_cls=field_cls)
+            setattr(self, field_name, instrumented_class)
+
+
+class _WrappedModel(object):
+
+    def __init__(self, wrapped, instrumentation, **kwargs):
+        """
+
+        :param instrumented_cls: The class to be instrumented
+        :param instrumentation_cls: the instrumentation cls
+        :param wrapped: the currently wrapped instance
+        :param kwargs: and kwargs to the passed to the instrumented class.
+        """
+        self._kwargs = kwargs
+        self._instrumentation = instrumentation
+        self._wrapped = wrapped
+
+    def _wrap(self, value):
+        if value.__class__ in (class_.class_ for class_ in self._instrumentation):
+            return _create_instrumented_model(
+                value, instrumentation=self._instrumentation, **self._kwargs)
+        elif hasattr(value, 'metadata') or isinstance(value, (dict, list)):
+            # Basically checks that the value is indeed an sqlmodel (it should have metadata)
+            return _create_wrapped_model(
+                value, instrumentation=self._instrumentation, **self._kwargs)
+        return value
+
+    def __getattr__(self, item):
+        if hasattr(self, '_wrapped'):
+            return self._wrap(getattr(self._wrapped, item))
+        else:
+            super(_WrappedModel, self).__getattribute__(item)
+
+    def __getitem__(self, item):
+        return self._wrap(self._wrapped[item])
+
+
+def _create_instrumented_model(original_model, mapi, instrumentation, **kwargs):
+    return type('Instrumented{0}'.format(original_model.__class__.__name__),
+                (_InstrumentedModel,),
+                {})(original_model, mapi, instrumentation, **kwargs)
+
+
+def _create_wrapped_model(original_model, mapi, instrumentation, **kwargs):
+    return type('Wrapped{0}'.format(original_model.__class__.__name__),
+                (_WrappedModel, ),
+                {})(original_model, instrumentation, mapi=mapi, **kwargs)
+
+
+def instrument(instrumentation, original_model, mapi):
+    for instrumented_field in instrumentation:
+        if isinstance(original_model, instrumented_field.class_):
+            return _create_instrumented_model(original_model, mapi, instrumentation)
+
+    return _create_wrapped_model(original_model, mapi, instrumentation)

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/storage/core.py
----------------------------------------------------------------------
diff --git a/aria/storage/core.py b/aria/storage/core.py
index 8302fc9..06c29e8 100644
--- a/aria/storage/core.py
+++ b/aria/storage/core.py
@@ -37,6 +37,8 @@ API:
     * drivers - module, a pool of ARIA standard drivers.
     * StorageDriver - class, abstract model implementation.
 """
+import copy
+from contextlib import contextmanager
 
 from aria.logger import LoggerMixin
 from . import sql_mapi
@@ -165,3 +167,16 @@ class ModelStorage(Storage):
         """
         for mapi in self.registered.values():
             mapi.drop()
+
+    @contextmanager
+    def instrument(self, *instrumentation):
+        original_instrumentation = {}
+
+        try:
+            for mapi in self.registered.values():
+                original_instrumentation[mapi] = copy.copy(mapi._instrumentation)
+                mapi._instrumentation.extend(instrumentation)
+            yield self
+        finally:
+            for mapi in self.registered.values():
+                mapi._instrumentation[:] = original_instrumentation[mapi]

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/storage/sql_mapi.py
----------------------------------------------------------------------
diff --git a/aria/storage/sql_mapi.py b/aria/storage/sql_mapi.py
index 730d007..4d7e233 100644
--- a/aria/storage/sql_mapi.py
+++ b/aria/storage/sql_mapi.py
@@ -29,6 +29,7 @@ from aria.utils.collections import OrderedDict
 from . import (
     api,
     exceptions,
+    collection_instrumentation
 )
 
 _predicates = {'ge': '__ge__',
@@ -63,7 +64,7 @@ class SQLAlchemyModelAPI(api.ModelAPI):
                 'Requested `{0}` with ID `{1}` was not found'
                 .format(self.model_cls.__name__, entry_id)
             )
-        return result
+        return self._instrument(result)
 
     def get_by_name(self, entry_name, include=None, **kwargs):
         assert hasattr(self.model_cls, 'name')
@@ -93,7 +94,7 @@ class SQLAlchemyModelAPI(api.ModelAPI):
 
         return ListResult(
             dict(total=total, size=size, offset=offset),
-            results
+            [self._instrument(result) for result in results]
         )
 
     def iter(self,
@@ -103,7 +104,8 @@ class SQLAlchemyModelAPI(api.ModelAPI):
              **kwargs):
         """Return a (possibly empty) list of `model_class` results
         """
-        return iter(self._get_query(include, filters, sort))
+        for result in self._get_query(include, filters, sort):
+            yield self._instrument(result)
 
     def put(self, entry, **kwargs):
         """Create a `model_class` instance from a serializable `model` object
@@ -378,6 +380,12 @@ class SQLAlchemyModelAPI(api.ModelAPI):
         for rel in instance.__mapper__.relationships:
             getattr(instance, rel.key)
 
+    def _instrument(self, model):
+        if self._instrumentation:
+            return collection_instrumentation.instrument(self._instrumentation, model, self)
+        else:
+            return model
+
 
 def init_storage(base_dir, filename='db.sqlite'):
     """

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/aria/utils/imports.py
----------------------------------------------------------------------
diff --git a/aria/utils/imports.py b/aria/utils/imports.py
index 64a48cf..35aa0fc 100644
--- a/aria/utils/imports.py
+++ b/aria/utils/imports.py
@@ -17,8 +17,8 @@
 Utility methods for dynamically loading python code
 """
 
-import importlib
 import pkgutil
+import importlib
 
 
 def import_fullname(name, paths=None):

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/tests/orchestrator/context/test_collection_instrumentation.py
----------------------------------------------------------------------
diff --git a/tests/orchestrator/context/test_collection_instrumentation.py b/tests/orchestrator/context/test_collection_instrumentation.py
index 1e6214a..ae3e8ac 100644
--- a/tests/orchestrator/context/test_collection_instrumentation.py
+++ b/tests/orchestrator/context/test_collection_instrumentation.py
@@ -15,8 +15,14 @@
 
 import pytest
 
-from aria.modeling.models import Attribute
-from aria.orchestrator.context import collection_instrumentation
+from aria.modeling import models
+from aria.storage import collection_instrumentation
+from aria.orchestrator.context import operation
+
+from tests import (
+    mock,
+    storage
+)
 
 
 class MockActor(object):
@@ -25,12 +31,16 @@ class MockActor(object):
         self.list_ = []
 
 
-class MockModel(object):
+class MockMAPI(object):
 
     def __init__(self):
-        self.attribute = type('MockModel', (object, ), {'model_cls': Attribute,
-                                                        'put': lambda *args, **kwargs: None,
-                                                        'update': lambda *args, **kwargs: None})()
+        pass
+
+    def put(self, *args, **kwargs):
+        pass
+
+    def update(self, *args, **kwargs):
+        pass
 
 
 class CollectionInstrumentation(object):
@@ -41,15 +51,15 @@ class CollectionInstrumentation(object):
 
     @pytest.fixture
     def model(self):
-        return MockModel()
+        return MockMAPI()
 
     @pytest.fixture
     def dict_(self, actor, model):
-        return collection_instrumentation._InstrumentedDict(model, actor, 'dict_')
+        return collection_instrumentation._InstrumentedDict(model, actor, 'dict_', models.Attribute)
 
     @pytest.fixture
     def list_(self, actor, model):
-        return collection_instrumentation._InstrumentedList(model, actor, 'list_')
+        return collection_instrumentation._InstrumentedList(model, actor, 'list_', models.Attribute)
 
 
 class TestDict(CollectionInstrumentation):
@@ -57,16 +67,16 @@ class TestDict(CollectionInstrumentation):
     def test_keys(self, actor, dict_):
         dict_.update(
             {
-                'key1': Attribute.wrap('key1', 'value1'),
-                'key2': Attribute.wrap('key2', 'value2')
+                'key1': models.Attribute.wrap('key1', 'value1'),
+                'key2': models.Attribute.wrap('key2', 'value2')
             }
         )
         assert sorted(dict_.keys()) == sorted(['key1', 'key2']) == sorted(actor.dict_.keys())
 
     def test_values(self, actor, dict_):
         dict_.update({
-            'key1': Attribute.wrap('key1', 'value1'),
-            'key2': Attribute.wrap('key1', 'value2')
+            'key1': models.Attribute.wrap('key1', 'value1'),
+            'key2': models.Attribute.wrap('key1', 'value2')
         })
         assert (sorted(dict_.values()) ==
                 sorted(['value1', 'value2']) ==
@@ -74,34 +84,34 @@ class TestDict(CollectionInstrumentation):
 
     def test_items(self, dict_):
         dict_.update({
-            'key1': Attribute.wrap('key1', 'value1'),
-            'key2': Attribute.wrap('key1', 'value2')
+            'key1': models.Attribute.wrap('key1', 'value1'),
+            'key2': models.Attribute.wrap('key1', 'value2')
         })
         assert sorted(dict_.items()) == sorted([('key1', 'value1'), ('key2', 'value2')])
 
     def test_iter(self, actor, dict_):
         dict_.update({
-            'key1': Attribute.wrap('key1', 'value1'),
-            'key2': Attribute.wrap('key1', 'value2')
+            'key1': models.Attribute.wrap('key1', 'value1'),
+            'key2': models.Attribute.wrap('key1', 'value2')
         })
         assert sorted(list(dict_)) == sorted(['key1', 'key2']) == sorted(actor.dict_.keys())
 
     def test_bool(self, dict_):
         assert not dict_
         dict_.update({
-            'key1': Attribute.wrap('key1', 'value1'),
-            'key2': Attribute.wrap('key1', 'value2')
+            'key1': models.Attribute.wrap('key1', 'value1'),
+            'key2': models.Attribute.wrap('key1', 'value2')
         })
         assert dict_
 
     def test_set_item(self, actor, dict_):
-        dict_['key1'] = Attribute.wrap('key1', 'value1')
+        dict_['key1'] = models.Attribute.wrap('key1', 'value1')
         assert dict_['key1'] == 'value1' == actor.dict_['key1'].value
-        assert isinstance(actor.dict_['key1'], Attribute)
+        assert isinstance(actor.dict_['key1'], models.Attribute)
 
     def test_nested(self, actor, dict_):
         dict_['key'] = {}
-        assert isinstance(actor.dict_['key'], Attribute)
+        assert isinstance(actor.dict_['key'], models.Attribute)
         assert dict_['key'] == actor.dict_['key'].value == {}
 
         dict_['key']['inner_key'] = 'value'
@@ -112,7 +122,7 @@ class TestDict(CollectionInstrumentation):
         assert dict_['key'].keys() == ['inner_key']
         assert dict_['key'].values() == ['value']
         assert dict_['key'].items() == [('inner_key', 'value')]
-        assert isinstance(actor.dict_['key'], Attribute)
+        assert isinstance(actor.dict_['key'], models.Attribute)
         assert isinstance(dict_['key'], collection_instrumentation._InstrumentedDict)
 
         dict_['key'].update({'updated_key': 'updated_value'})
@@ -123,7 +133,7 @@ class TestDict(CollectionInstrumentation):
         assert sorted(dict_['key'].values()) == sorted(['value', 'updated_value'])
         assert sorted(dict_['key'].items()) == sorted([('inner_key', 'value'),
                                                        ('updated_key', 'updated_value')])
-        assert isinstance(actor.dict_['key'], Attribute)
+        assert isinstance(actor.dict_['key'], models.Attribute)
         assert isinstance(dict_['key'], collection_instrumentation._InstrumentedDict)
 
         dict_.update({'key': 'override_value'})
@@ -131,12 +141,12 @@ class TestDict(CollectionInstrumentation):
         assert 'key' in dict_
         assert dict_['key'] == 'override_value'
         assert len(actor.dict_) == 1
-        assert isinstance(actor.dict_['key'], Attribute)
+        assert isinstance(actor.dict_['key'], models.Attribute)
         assert actor.dict_['key'].value == 'override_value'
 
     def test_get_item(self, actor, dict_):
-        dict_['key1'] = Attribute.wrap('key1', 'value1')
-        assert isinstance(actor.dict_['key1'], Attribute)
+        dict_['key1'] = models.Attribute.wrap('key1', 'value1')
+        assert isinstance(actor.dict_['key1'], models.Attribute)
 
     def test_update(self, actor, dict_):
         dict_['key1'] = 'value1'
@@ -145,7 +155,7 @@ class TestDict(CollectionInstrumentation):
         dict_.update(new_dict)
         assert len(dict_) == 2
         assert dict_['key2'] == 'value2'
-        assert isinstance(actor.dict_['key2'], Attribute)
+        assert isinstance(actor.dict_['key2'], models.Attribute)
 
         new_dict = {}
         new_dict.update(dict_)
@@ -172,20 +182,20 @@ class TestDict(CollectionInstrumentation):
 class TestList(CollectionInstrumentation):
 
     def test_append(self, actor, list_):
-        list_.append(Attribute.wrap('name', 'value1'))
+        list_.append(models.Attribute.wrap('name', 'value1'))
         list_.append('value2')
         assert len(actor.list_) == 2
         assert len(list_) == 2
-        assert isinstance(actor.list_[0], Attribute)
+        assert isinstance(actor.list_[0], models.Attribute)
         assert list_[0] == 'value1'
 
-        assert isinstance(actor.list_[1], Attribute)
+        assert isinstance(actor.list_[1], models.Attribute)
         assert list_[1] == 'value2'
 
         list_[0] = 'new_value1'
         list_[1] = 'new_value2'
-        assert isinstance(actor.list_[1], Attribute)
-        assert isinstance(actor.list_[1], Attribute)
+        assert isinstance(actor.list_[1], models.Attribute)
+        assert isinstance(actor.list_[1], models.Attribute)
         assert list_[0] == 'new_value1'
         assert list_[1] == 'new_value2'
 
@@ -214,12 +224,12 @@ class TestList(CollectionInstrumentation):
         list_.append([])
 
         list_[0].append('inner_item')
-        assert isinstance(actor.list_[0], Attribute)
+        assert isinstance(actor.list_[0], models.Attribute)
         assert len(list_) == 1
         assert list_[0][0] == 'inner_item'
 
         list_[0].append('new_item')
-        assert isinstance(actor.list_[0], Attribute)
+        assert isinstance(actor.list_[0], models.Attribute)
         assert len(list_) == 1
         assert list_[0][1] == 'new_item'
 
@@ -231,23 +241,85 @@ class TestDictList(CollectionInstrumentation):
     def test_dict_in_list(self, actor, list_):
         list_.append({})
         assert len(list_) == 1
-        assert isinstance(actor.list_[0], Attribute)
+        assert isinstance(actor.list_[0], models.Attribute)
         assert actor.list_[0].value == {}
 
         list_[0]['key'] = 'value'
         assert list_[0]['key'] == 'value'
         assert len(actor.list_) == 1
-        assert isinstance(actor.list_[0], Attribute)
+        assert isinstance(actor.list_[0], models.Attribute)
         assert actor.list_[0].value['key'] == 'value'
 
     def test_list_in_dict(self, actor, dict_):
         dict_['key'] = []
         assert len(dict_) == 1
-        assert isinstance(actor.dict_['key'], Attribute)
+        assert isinstance(actor.dict_['key'], models.Attribute)
         assert actor.dict_['key'].value == []
 
         dict_['key'].append('value')
         assert dict_['key'][0] == 'value'
         assert len(actor.dict_) == 1
-        assert isinstance(actor.dict_['key'], Attribute)
+        assert isinstance(actor.dict_['key'], models.Attribute)
         assert actor.dict_['key'].value[0] == 'value'
+
+
+class TestModelInstrumentation(object):
+
+    @pytest.fixture
+    def workflow_ctx(self, tmpdir):
+        context = mock.context.simple(str(tmpdir), inmemory=True)
+        yield context
+        storage.release_sqlite_storage(context.model)
+
+    def test_attributes_access(self, workflow_ctx):
+        node = workflow_ctx.model.node.list()[0]
+        task = models.Task(node=node)
+        workflow_ctx.model.task.put(task)
+
+        ctx = operation.NodeOperationContext(
+            task.id, node.id, name='', service_id=workflow_ctx.model.service.list()[0].id,
+            model_storage=workflow_ctx.model, resource_storage=workflow_ctx.resource,
+            execution_id=1)
+
+        def _run_assertions(is_under_ctx):
+            def ctx_assert(expr):
+                if is_under_ctx:
+                    assert expr
+                else:
+                    assert not expr
+
+            ctx_assert(isinstance(ctx.node.attributes,
+                                  collection_instrumentation._InstrumentedDict))
+            assert not isinstance(ctx.node.properties,
+                                  collection_instrumentation._InstrumentedCollection)
+
+            for rel in ctx.node.inbound_relationships:
+                ctx_assert(isinstance(rel, collection_instrumentation._WrappedModel))
+                ctx_assert(isinstance(rel.source_node.attributes,
+                                      collection_instrumentation._InstrumentedDict))
+                ctx_assert(isinstance(rel.target_node.attributes,
+                                      collection_instrumentation._InstrumentedDict))
+
+            for node in ctx.model.node:
+                ctx_assert(isinstance(node.attributes,
+                                      collection_instrumentation._InstrumentedDict))
+                assert not isinstance(node.properties,
+                                      collection_instrumentation._InstrumentedCollection)
+
+            for rel in ctx.model.relationship:
+                ctx_assert(isinstance(rel, collection_instrumentation._WrappedModel))
+
+                ctx_assert(isinstance(rel.source_node.attributes,
+                                      collection_instrumentation._InstrumentedDict))
+                ctx_assert(isinstance(rel.target_node.attributes,
+                                      collection_instrumentation._InstrumentedDict))
+
+                assert not isinstance(rel.source_node.properties,
+                                      collection_instrumentation._InstrumentedCollection)
+                assert not isinstance(rel.target_node.properties,
+                                      collection_instrumentation._InstrumentedCollection)
+
+        with ctx.model.instrument(models.Node.attributes):
+            _run_assertions(True)
+
+        _run_assertions(False)

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/tests/orchestrator/execution_plugin/test_ctx_proxy_server.py
----------------------------------------------------------------------
diff --git a/tests/orchestrator/execution_plugin/test_ctx_proxy_server.py b/tests/orchestrator/execution_plugin/test_ctx_proxy_server.py
index 1b19fd9..7ab1bdb 100644
--- a/tests/orchestrator/execution_plugin/test_ctx_proxy_server.py
+++ b/tests/orchestrator/execution_plugin/test_ctx_proxy_server.py
@@ -138,7 +138,7 @@ class TestCtxProxy(object):
     @pytest.fixture
     def ctx(self, mocker):
         class MockCtx(object):
-            pass
+            INSTRUMENTATION_FIELDS = ()
         ctx = MockCtx()
         properties = {
             'prop1': 'value1',

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/tests/orchestrator/execution_plugin/test_ssh.py
----------------------------------------------------------------------
diff --git a/tests/orchestrator/execution_plugin/test_ssh.py b/tests/orchestrator/execution_plugin/test_ssh.py
index 899a007..8b326e7 100644
--- a/tests/orchestrator/execution_plugin/test_ssh.py
+++ b/tests/orchestrator/execution_plugin/test_ssh.py
@@ -422,15 +422,24 @@ class TestFabricEnvHideGroupsAndRunCommands(object):
             raise RuntimeError
 
     class _Ctx(object):
+        INSTRUMENTATION_FIELDS = ()
+
         class Task(object):
             @staticmethod
             def abort(message=None):
                 models.Task.abort(message)
             actor = None
+
         class Actor(object):
             host = None
+
+        class Model(object):
+            @contextlib.contextmanager
+            def instrument(self, *args, **kwargs):
+                yield
         task = Task
         task.actor = Actor
+        model = Model()
         logger = logging.getLogger()
 
     @staticmethod
@@ -439,7 +448,6 @@ class TestFabricEnvHideGroupsAndRunCommands(object):
         yield
     _Ctx.logging_handlers = _mock_self_logging
 
-
     @pytest.fixture(autouse=True)
     def _setup(self, mocker):
         self.default_fabric_env = {

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/tests/orchestrator/workflows/core/test_task.py
----------------------------------------------------------------------
diff --git a/tests/orchestrator/workflows/core/test_task.py b/tests/orchestrator/workflows/core/test_task.py
index a717e19..c0d3616 100644
--- a/tests/orchestrator/workflows/core/test_task.py
+++ b/tests/orchestrator/workflows/core/test_task.py
@@ -100,7 +100,7 @@ class TestOperationTask(object):
         storage_task = ctx.model.task.get_by_name(core_task.name)
         assert storage_task.plugin is storage_plugin
         assert storage_task.execution_name == ctx.execution.name
-        assert storage_task.actor == core_task.context.node._original_model
+        assert storage_task.actor == core_task.context.node
         assert core_task.model_task == storage_task
         assert core_task.name == api_task.name
         assert core_task.function == api_task.function

http://git-wip-us.apache.org/repos/asf/incubator-ariatosca/blob/180e0a1c/tests/orchestrator/workflows/executor/test_process_executor_extension.py
----------------------------------------------------------------------
diff --git a/tests/orchestrator/workflows/executor/test_process_executor_extension.py b/tests/orchestrator/workflows/executor/test_process_executor_extension.py
index e4944df..7969457 100644
--- a/tests/orchestrator/workflows/executor/test_process_executor_extension.py
+++ b/tests/orchestrator/workflows/executor/test_process_executor_extension.py
@@ -66,7 +66,8 @@ class MockProcessExecutorExtension(object):
     def decorate(self):
         def decorator(function):
             def wrapper(ctx, **operation_arguments):
-                ctx.node.attributes['out'] = {'wrapper_arguments': operation_arguments}
+                with ctx.model.instrument(ctx.model.node.model_cls.attributes):
+                    ctx.node.attributes['out'] = {'wrapper_arguments': operation_arguments}
                 function(ctx=ctx, **operation_arguments)
             return wrapper
         return decorator