Source code for ceilometer.api.hooks

#
# Copyright 2012 New Dream Network, LLC (DreamHost)
#
# 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 threading

from oslo_config import cfg

from pecan import hooks

from ceilometer.i18n import _LE
from ceilometer.openstack.common import log
from ceilometer import pipeline
from ceilometer import storage

LOG = log.getLogger(__name__)


[docs]class ConfigHook(hooks.PecanHook): """Attach the configuration object to the request. That allows controllers to get it. """ @staticmethod
[docs] def before(state): state.request.cfg = cfg.CONF
[docs]class DBHook(hooks.PecanHook): def __init__(self): self.storage_connection = DBHook.get_connection('metering') self.event_storage_connection = DBHook.get_connection('event') self.alarm_storage_connection = DBHook.get_connection('alarm') if (not self.storage_connection and not self.event_storage_connection and not self.alarm_storage_connection): raise Exception("Api failed to start. Failed to connect to " "databases, purpose: %s" % ', '.join(['metering', 'event', 'alarm']))
[docs] def before(self, state): state.request.storage_conn = self.storage_connection state.request.event_storage_conn = self.event_storage_connection state.request.alarm_storage_conn = self.alarm_storage_connection
@staticmethod
[docs] def get_connection(purpose): try: return storage.get_connection_from_config(cfg.CONF, purpose) except Exception as err: params = {"purpose": purpose, "err": err} LOG.exception(_LE("Failed to connect to db, purpose %(purpose)s " "retry later: %(err)s") % params)
[docs]class PipelineHook(hooks.PecanHook): """Create and attach a pipeline to the request. That allows new samples to be posted via the /v2/meters/ API. """ def __init__(self): # this is done here as the cfg options are not available # when the file is imported. self.pipeline_manager = pipeline.setup_pipeline()
[docs] def before(self, state): state.request.pipeline_manager = self.pipeline_manager
[docs]class TranslationHook(hooks.PecanHook): def __init__(self): # Use thread local storage to make this thread safe in situations # where one pecan instance is being used to serve multiple request # threads. self.local_error = threading.local() self.local_error.translatable_error = None
[docs] def before(self, state): self.local_error.translatable_error = None
[docs] def after(self, state): if hasattr(state.response, 'translatable_error'): self.local_error.translatable_error = ( state.response.translatable_error)