WBE notification message validation

Add send and receive validation of the notify
message that is sent between executors and workers
to be more robust around invalid message formats
being sent and received.

Part of blueprint wbe-message-validation

Change-Id: I7300d6f2d00e48c4f989c7f958a028bdff4afdd4

requirements.txt

@@ -10,3 +10,4 @@ Babel>=1.3
 stevedore>=0.14
 # Backport for concurrent.futures which exists in 3.2+
 futures>=2.1.3
+jsonschema>=2.0.0,<3.0.0

taskflow/engines/worker_based/executor.py

@@ -14,6 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import functools
 import logging
 
 from taskflow.engines.action_engine import executor
@@ -74,7 +75,10 @@ class WorkerTaskExecutor(executor.TaskExecutorBase):
         self._requests_cache = cache.RequestsCache()
         self._workers_cache = cache.WorkersCache()
         handlers = {
-            pr.NOTIFY: self._process_notify,
+            pr.NOTIFY: [
+                self._process_notify,
+                functools.partial(pr.Notify.validate, response=True),
+            ],
             pr.RESPONSE: self._process_response,
         }
         self._proxy = proxy.Proxy(uuid, exchange, handlers,

taskflow/engines/worker_based/protocol.py

@@ -17,9 +17,12 @@
 import abc
 
 from concurrent import futures
+import jsonschema
+from jsonschema import exceptions as schema_exc
 import six
 
 from taskflow.engines.action_engine import executor
+from taskflow import exceptions as excp
 from taskflow.types import time
 from taskflow.utils import misc
 from taskflow.utils import reflection
@@ -78,12 +81,54 @@ class Notify(Message):
     """Represents notify message type."""
     TYPE = NOTIFY
 
+    # NOTE(harlowja): the executor (the entity who initially requests a worker
+    # to send back a notification response) schema is different than the
+    # worker response schema (that's why there are two schemas here).
+    _RESPONSE_SCHEMA = {
+        "type": "object",
+        'properties': {
+            'topic': {
+                "type": "string",
+            },
+            'tasks': {
+                "type": "array",
+                "items": {
+                    "type": "string",
+                },
+            }
+        },
+        "required": ["topic", 'tasks'],
+        "additionalProperties": False,
+    }
+    _SENDER_SCHEMA = {
+        "type": "object",
+        "additionalProperties": False,
+    }
+
     def __init__(self, **data):
         self._data = data
 
     def to_dict(self):
         return self._data
 
+    @classmethod
+    def validate(cls, data, response):
+        if response:
+            schema = cls._RESPONSE_SCHEMA
+        else:
+            schema = cls._SENDER_SCHEMA
+        try:
+            jsonschema.validate(data, schema)
+        except schema_exc.ValidationError as e:
+            if response:
+                raise excp.InvalidFormat("%s message response data not of the"
+                                         " expected format: %s"
+                                         % (cls.TYPE, e.message), e)
+            else:
+                raise excp.InvalidFormat("%s message sender data not of the"
+                                         " expected format: %s"
+                                         % (cls.TYPE, e.message), e)
+
 
 class Request(Message):
     """Represents request with execution results.

taskflow/engines/worker_based/server.py

@@ -45,7 +45,10 @@ class Server(object):
 
     def __init__(self, topic, exchange, executor, endpoints, **kwargs):
         handlers = {
-            pr.NOTIFY: delayed(executor)(self._process_notify),
+            pr.NOTIFY: [
+                delayed(executor)(self._process_notify),
+                functools.partial(pr.Notify.validate, response=False),
+            ],
             pr.REQUEST: delayed(executor)(self._process_request),
         }
         self._proxy = proxy.Proxy(topic, exchange, handlers,