Boden R fea8bb64ba Expose/Improve callback notification interface
This patch builds a small hierarchy of event objects that
represent the payload for callback notification events. The
overall goal of this work is to begin moving away from the
existing unstructured  **kwargs passed today and standardize
on a common set of event payload objects; the beginning of such
contained herein.

A PoC/dummy patch for neutron is provided in [1] that exemplifies
consumption of the new API by:
- Removes neutron.callbacks and moves all uses to
neutron_lib.callbacks.
- Neutron uses of callbacks for BEFORE_RESPONSE events
now use neutron-lib.
- Neutron uses of callbacks for ROUTER and PROCESS
resource events now use neutron-lib.
- Neutron UTs updated to pass with this patch.

For existing discussion on this approach please see [2][3].

Co-Authored-By: Armando Migliaccio <armamig@gmail.com>

[1] https://review.openstack.org/400404/
[2] https://review.openstack.org/#/c/345718
[3] https://review.openstack.org/#/c/342304

Change-Id: If76457b1f0d5d3479e394d0dba3b22a90928f0f2
2017-01-11 13:47:12 -07:00

59 lines
1.9 KiB
Python

# 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.
from neutron_lib._i18n import _
from neutron_lib import exceptions
class Invalid(exceptions.NeutronException):
message = _("The value '%(value)s' for %(element)s is not valid.")
class CallbackFailure(exceptions.MultipleExceptions):
def __init__(self, errors):
self.errors = errors
def __str__(self):
if isinstance(self.errors, list):
return ','.join(str(error) for error in self.errors)
else:
return str(self.errors)
@property
def inner_exceptions(self):
"""The list of unpacked errors for this exception.
:return: A list of unpacked errors for this exception. An unpacked
error is the Exception's 'error' attribute if it inherits from
NotificationError, otherwise it's the exception itself.
"""
if isinstance(self.errors, list):
return [self._unpack_if_notification_error(e) for e in self.errors]
return [self._unpack_if_notification_error(self.errors)]
@staticmethod
def _unpack_if_notification_error(exc):
if isinstance(exc, NotificationError):
return exc.error
return exc
class NotificationError(object):
def __init__(self, callback_id, error):
self.callback_id = callback_id
self.error = error
def __str__(self):
return 'Callback %s failed with "%s"' % (self.callback_id, self.error)