Transform wrap_exception notification to versioned format

A new versioned notification is emitted from the wrap_exception
decorator.

Change-Id: I8fcbce111537dae6ad3ba0961fb761540ae800ed
Partially-Implements: bp versioned-notification-transformation-newton

nova/exception_wrapper.py

@@ -0,0 +1,94 @@
+#    Licensed 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.
+
+import functools
+import inspect
+
+from oslo_utils import excutils
+import six
+
+import nova.conf
+from nova.notifications.objects import base
+from nova.notifications.objects import exception
+from nova.objects import fields
+from nova import safe_utils
+
+CONF = nova.conf.CONF
+
+
+def _emit_exception_notification(notifier, context, ex, function_name, args,
+                                 binary):
+    _emit_legacy_exception_notification(notifier, context, ex, function_name,
+                                        args)
+    _emit_versioned_exception_notification(context, ex, binary)
+
+
+def _emit_versioned_exception_notification(context, ex, binary):
+    versioned_exception_payload = exception.ExceptionPayload.from_exception(ex)
+    publisher = base.NotificationPublisher(context=context, host=CONF.host,
+                                           binary=binary)
+    event_type = base.EventType(
+            object='compute',
+            action=fields.NotificationAction.EXCEPTION)
+    notification = exception.ExceptionNotification(
+        publisher=publisher,
+        event_type=event_type,
+        priority=fields.NotificationPriority.ERROR,
+        payload=versioned_exception_payload)
+    notification.emit(context)
+
+
+def _emit_legacy_exception_notification(notifier, context, ex, function_name,
+                                       args):
+    payload = dict(exception=ex, args=args)
+    notifier.error(context, function_name, payload)
+
+
+def wrap_exception(notifier=None, get_notifier=None, binary=None):
+    """This decorator wraps a method to catch any exceptions that may
+    get thrown. It also optionally sends the exception to the notification
+    system.
+    """
+    def inner(f):
+        def wrapped(self, context, *args, **kw):
+            # Don't store self or context in the payload, it now seems to
+            # contain confidential information.
+            try:
+                return f(self, context, *args, **kw)
+            except Exception as e:
+                with excutils.save_and_reraise_exception():
+                    if notifier or get_notifier:
+                        call_dict = _get_call_dict(
+                            f, self, context, *args, **kw)
+                        function_name = f.__name__
+                        _emit_exception_notification(
+                            notifier or get_notifier(), context, e,
+                            function_name, call_dict, binary)
+
+        return functools.wraps(f)(wrapped)
+    return inner
+
+
+def _get_call_dict(function, self, context, *args, **kw):
+    wrapped_func = safe_utils.get_wrapped_function(function)
+
+    call_dict = inspect.getcallargs(wrapped_func, self,
+                                    context, *args, **kw)
+    # self can't be serialized and shouldn't be in the
+    # payload
+    call_dict.pop('self', None)
+    return _cleanse_dict(call_dict)
+
+
+def _cleanse_dict(original):
+    """Strip all admin_password, new_pass, rescue_pass keys from a dict."""
+    return {k: v for k, v in six.iteritems(original) if "_pass" not in k}