oslo.messaging/oslo_messaging/notify/notifier.py
ChangBo Guo(gcb) 6b20fa8597 Improvement of logging acorrding to oslo.i18n guideline
1. Use translation marker functions, their argument must just be a string
2. Any message with more than one variable should use named
   interpolation instead of positional to allow translators
   to move the variables around in the string to account for
   differences in grammar and writing direction.
3. String interpolation should be delayed to be handled by the logging
   code, rather than being done at the point of the logging call.
For more details, please refert to oslo.i18n guideline [1]

Note: this commit doesn't touch test code.

[1] http://docs.openstack.org/developer/oslo.i18n/guidelines.html

Change-Id: I5f013d65b20396bbe0e5a2cceaed2a33fad1af23
2016-01-07 13:26:55 +08:00

366 lines
13 KiB
Python

# Copyright 2011 OpenStack Foundation.
# All Rights Reserved.
# Copyright 2013 Red Hat, Inc.
#
# 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 abc
import logging
import uuid
from oslo_config import cfg
from oslo_utils import timeutils
import six
from stevedore import named
from oslo_messaging._i18n import _LE
from oslo_messaging import serializer as msg_serializer
from oslo_messaging import transport as msg_transport
_notifier_opts = [
cfg.MultiStrOpt('driver',
default=[],
deprecated_name='notification_driver',
deprecated_group='DEFAULT',
help='The Drivers(s) to handle sending notifications. '
'Possible values are messaging, messagingv2, '
'routing, log, test, noop'),
cfg.StrOpt('transport_url',
deprecated_name='notification_transport_url',
deprecated_group='DEFAULT',
help='A URL representing the messaging driver to use for '
'notifications. If not set, we fall back to the same '
'configuration used for RPC.'),
cfg.ListOpt('topics',
default=['notifications', ],
deprecated_opts=[
cfg.DeprecatedOpt('topics',
group='rpc_notifier2'),
cfg.DeprecatedOpt('notification_topics',
group='DEFAULT')
],
help='AMQP topic used for OpenStack notifications.'),
]
_LOG = logging.getLogger(__name__)
@six.add_metaclass(abc.ABCMeta)
class Driver(object):
"""Base driver for Notifications"""
def __init__(self, conf, topics, transport):
"""base driver initialization
:param conf: configuration options
:param topics: list of topics
:param transport: transport driver to use
"""
self.conf = conf
self.topics = topics
self.transport = transport
@abc.abstractmethod
def notify(self, ctxt, msg, priority, retry):
"""send a single notification with a specific priority
:param ctxt: current request context
:param msg: message to be sent
:type msg: str
:param priority: priority of the message
:type priority: str
:param retry: an connection retries configuration
None or -1 means to retry forever
0 means no retry
N means N retries
:type retry: int
"""
pass
def get_notification_transport(conf, url=None,
allowed_remote_exmods=None, aliases=None):
conf.register_opts(_notifier_opts,
group='oslo_messaging_notifications')
if url is None:
url = conf.oslo_messaging_notifications.transport_url
return msg_transport.get_transport(conf, url,
allowed_remote_exmods, aliases)
class Notifier(object):
"""Send notification messages.
The Notifier class is used for sending notification messages over a
messaging transport or other means.
Notification messages follow the following format::
{'message_id': six.text_type(uuid.uuid4()),
'publisher_id': 'compute.host1',
'timestamp': timeutils.utcnow(),
'priority': 'WARN',
'event_type': 'compute.create_instance',
'payload': {'instance_id': 12, ... }}
A Notifier object can be instantiated with a transport object and a
publisher ID:
notifier = messaging.Notifier(get_notification_transport(CONF),
'compute')
and notifications are sent via drivers chosen with the driver
config option and on the topics chosen with the topics config
option in [oslo_messaging_notifications] section.
Alternatively, a Notifier object can be instantiated with a specific
driver or topic::
transport = notifier.get_notification_transport(CONF)
notifier = notifier.Notifier(transport,
'compute.host',
driver='messaging',
topic='notifications')
Notifier objects are relatively expensive to instantiate (mostly the cost
of loading notification drivers), so it is possible to specialize a given
Notifier object with a different publisher id using the prepare() method::
notifier = notifier.prepare(publisher_id='compute')
notifier.info(ctxt, event_type, payload)
"""
def __init__(self, transport, publisher_id=None,
driver=None, topic=None,
serializer=None, retry=None):
"""Construct a Notifier object.
:param transport: the transport to use for sending messages
:type transport: oslo_messaging.Transport
:param publisher_id: field in notifications sent, for example
'compute.host1'
:type publisher_id: str
:param driver: a driver to lookup from oslo_messaging.notify.drivers
:type driver: str
:param topic: the topic which to send messages on
:type topic: str
:param serializer: an optional entity serializer
:type serializer: Serializer
:param retry: an connection retries configuration
None or -1 means to retry forever
0 means no retry
N means N retries
:type retry: int
"""
conf = transport.conf
conf.register_opts(_notifier_opts,
group='oslo_messaging_notifications')
self.transport = transport
self.publisher_id = publisher_id
self.retry = retry
self._driver_names = ([driver] if driver is not None else
conf.oslo_messaging_notifications.driver)
self._topics = ([topic] if topic is not None else
conf.oslo_messaging_notifications.topics)
self._serializer = serializer or msg_serializer.NoOpSerializer()
self._driver_mgr = named.NamedExtensionManager(
'oslo.messaging.notify.drivers',
names=self._driver_names,
invoke_on_load=True,
invoke_args=[conf],
invoke_kwds={
'topics': self._topics,
'transport': self.transport,
}
)
_marker = object()
def prepare(self, publisher_id=_marker, retry=_marker):
"""Return a specialized Notifier instance.
Returns a new Notifier instance with the supplied publisher_id. Allows
sending notifications from multiple publisher_ids without the overhead
of notification driver loading.
:param publisher_id: field in notifications sent, for example
'compute.host1'
:type publisher_id: str
:param retry: an connection retries configuration
None or -1 means to retry forever
0 means no retry
N means N retries
:type retry: int
"""
return _SubNotifier._prepare(self, publisher_id, retry=retry)
def _notify(self, ctxt, event_type, payload, priority, publisher_id=None,
retry=None):
payload = self._serializer.serialize_entity(ctxt, payload)
ctxt = self._serializer.serialize_context(ctxt)
msg = dict(message_id=six.text_type(uuid.uuid4()),
publisher_id=publisher_id or self.publisher_id,
event_type=event_type,
priority=priority,
payload=payload,
timestamp=six.text_type(timeutils.utcnow()))
def do_notify(ext):
try:
ext.obj.notify(ctxt, msg, priority, retry or self.retry)
except Exception as e:
_LOG.exception(_LE("Problem '%(e)s' attempting to send to "
"notification system. Payload=%(payload)s"),
dict(e=e, payload=payload))
if self._driver_mgr.extensions:
self._driver_mgr.map(do_notify)
def audit(self, ctxt, event_type, payload):
"""Send a notification at audit level.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'AUDIT')
def debug(self, ctxt, event_type, payload):
"""Send a notification at debug level.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'DEBUG')
def info(self, ctxt, event_type, payload):
"""Send a notification at info level.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'INFO')
def warn(self, ctxt, event_type, payload):
"""Send a notification at warning level.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'WARN')
warning = warn
def error(self, ctxt, event_type, payload):
"""Send a notification at error level.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'ERROR')
def critical(self, ctxt, event_type, payload):
"""Send a notification at critical level.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'CRITICAL')
def sample(self, ctxt, event_type, payload):
"""Send a notification at sample level.
Sample notifications are for high-frequency events
that typically contain small payloads. eg: "CPU = 70%"
Not all drivers support the sample level
(log, for example) so these could be dropped.
:param ctxt: a request context dict
:type ctxt: dict
:param event_type: describes the event, for example
'compute.create_instance'
:type event_type: str
:param payload: the notification payload
:type payload: dict
:raises: MessageDeliveryFailure
"""
self._notify(ctxt, event_type, payload, 'SAMPLE')
class _SubNotifier(Notifier):
_marker = Notifier._marker
def __init__(self, base, publisher_id, retry):
self._base = base
self.transport = base.transport
self.publisher_id = publisher_id
self.retry = retry
self._serializer = self._base._serializer
self._driver_mgr = self._base._driver_mgr
def _notify(self, ctxt, event_type, payload, priority):
super(_SubNotifier, self)._notify(ctxt, event_type, payload, priority)
@classmethod
def _prepare(cls, base, publisher_id=_marker, retry=_marker):
if publisher_id is cls._marker:
publisher_id = base.publisher_id
if retry is cls._marker:
retry = base.retry
return cls(base, publisher_id, retry=retry)