Add openstack-common's local and notifier modules

Change-Id: I90e063934d64598b440676b63b4be55262f923f1

glance/openstack/common/local.py

@@ -0,0 +1,37 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+"""Greenthread local storage of variables using weak references"""
+
+import weakref
+
+from eventlet import corolocal
+
+
+class WeakLocal(corolocal.local):
+    def __getattribute__(self, attr):
+        rval = corolocal.local.__getattribute__(self, attr)
+        if rval:
+            rval = rval()
+        return rval
+
+    def __setattr__(self, attr, value):
+        value = weakref.ref(value)
+        return corolocal.local.__setattr__(self, attr, value)
+
+
+store = WeakLocal()

glance/openstack/common/notifier/__init__.py

@@ -0,0 +1,14 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.

glance/openstack/common/notifier/api.py

@@ -0,0 +1,141 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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 inspect
+import uuid
+
+from glance.openstack.common import cfg
+from glance.openstack.common import context
+from glance.openstack.common import importutils
+from glance.openstack.common import jsonutils
+from glance.openstack.common import log as logging
+from glance.openstack.common import timeutils
+
+
+LOG = logging.getLogger(__name__)
+
+notifier_opts = [
+    cfg.StrOpt('notification_driver',
+               default='glance.openstack.common.notifier.no_op_notifier',
+               help='Default driver for sending notifications'),
+    cfg.StrOpt('default_notification_level',
+               default='INFO',
+               help='Default notification level for outgoing notifications'),
+    cfg.StrOpt('default_publisher_id',
+               default='$host',
+               help='Default publisher_id for outgoing notifications'),
+    ]
+
+CONF = cfg.CONF
+CONF.register_opts(notifier_opts)
+
+WARN = 'WARN'
+INFO = 'INFO'
+ERROR = 'ERROR'
+CRITICAL = 'CRITICAL'
+DEBUG = 'DEBUG'
+
+log_levels = (DEBUG, WARN, INFO, ERROR, CRITICAL)
+
+
+class BadPriorityException(Exception):
+    pass
+
+
+def notify_decorator(name, fn):
+    """ decorator for notify which is used from utils.monkey_patch()
+
+        :param name: name of the function
+        :param function: - object of the function
+        :returns: function -- decorated function
+
+    """
+    def wrapped_func(*args, **kwarg):
+        body = {}
+        body['args'] = []
+        body['kwarg'] = {}
+        for arg in args:
+            body['args'].append(arg)
+        for key in kwarg:
+            body['kwarg'][key] = kwarg[key]
+
+        ctxt = context.get_context_from_function_and_args(fn, args, kwarg)
+        notify(ctxt,
+               CONF.default_publisher_id,
+               name,
+               CONF.default_notification_level,
+               body)
+        return fn(*args, **kwarg)
+    return wrapped_func
+
+
+def publisher_id(service, host=None):
+    if not host:
+        host = CONF.host
+    return "%s.%s" % (service, host)
+
+
+def notify(context, publisher_id, event_type, priority, payload):
+    """Sends a notification using the specified driver
+
+    :param publisher_id: the source worker_type.host of the message
+    :param event_type:   the literal type of event (ex. Instance Creation)
+    :param priority:     patterned after the enumeration of Python logging
+                         levels in the set (DEBUG, WARN, INFO, ERROR, CRITICAL)
+    :param payload:       A python dictionary of attributes
+
+    Outgoing message format includes the above parameters, and appends the
+    following:
+
+    message_id
+      a UUID representing the id for this notification
+
+    timestamp
+      the GMT timestamp the notification was sent at
+
+    The composite message will be constructed as a dictionary of the above
+    attributes, which will then be sent via the transport mechanism defined
+    by the driver.
+
+    Message example::
+
+        {'message_id': str(uuid.uuid4()),
+         'publisher_id': 'compute.host1',
+         'timestamp': timeutils.utcnow(),
+         'priority': 'WARN',
+         'event_type': 'compute.create_instance',
+         'payload': {'instance_id': 12, ... }}
+
+    """
+    if priority not in log_levels:
+        raise BadPriorityException(
+                 _('%s not in valid priorities') % priority)
+
+    # Ensure everything is JSON serializable.
+    payload = jsonutils.to_primitive(payload, convert_instances=True)
+
+    driver = importutils.import_module(CONF.notification_driver)
+    msg = dict(message_id=str(uuid.uuid4()),
+                   publisher_id=publisher_id,
+                   event_type=event_type,
+                   priority=priority,
+                   payload=payload,
+                   timestamp=str(timeutils.utcnow()))
+    try:
+        driver.notify(context, msg)
+    except Exception, e:
+        LOG.exception(_("Problem '%(e)s' attempting to "
+                        "send to notification system. Payload=%(payload)s") %
+                        locals())

glance/openstack/common/notifier/list_notifier.py

@@ -0,0 +1,116 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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 glance.openstack.common import cfg
+from glance.openstack.common import importutils
+from glance.openstack.common import log as logging
+
+
+list_notifier_drivers_opt = cfg.MultiStrOpt('list_notifier_drivers',
+        default=['glance.openstack.common.notifier.no_op_notifier'],
+        help='List of drivers to send notifications')
+
+CONF = cfg.CONF
+CONF.register_opt(list_notifier_drivers_opt)
+
+LOG = logging.getLogger(__name__)
+
+drivers = None
+
+
+class ImportFailureNotifier(object):
+    """Noisily re-raises some exception over-and-over when notify is called."""
+
+    def __init__(self, exception):
+        self.exception = exception
+
+    def notify(self, context, message):
+        raise self.exception
+
+
+def _get_drivers():
+    """Instantiates and returns drivers based on the flag values."""
+    global drivers
+    if drivers is None:
+        drivers = []
+        for notification_driver in CONF.list_notifier_drivers:
+            try:
+                drivers.append(importutils.import_module(notification_driver))
+            except ImportError as e:
+                drivers.append(ImportFailureNotifier(e))
+    return drivers
+
+
+def add_driver(notification_driver):
+    """Add a notification driver at runtime."""
+    # Make sure the driver list is initialized.
+    _get_drivers()
+    if isinstance(notification_driver, basestring):
+        # Load and add
+        try:
+            drivers.append(importutils.import_module(notification_driver))
+        except ImportError as e:
+            drivers.append(ImportFailureNotifier(e))
+    else:
+        # Driver is already loaded; just add the object.
+        drivers.append(notification_driver)
+
+
+def _object_name(obj):
+    name = []
+    if hasattr(obj, '__module__'):
+        name.append(obj.__module__)
+    if hasattr(obj, '__name__'):
+        name.append(obj.__name__)
+    else:
+        name.append(obj.__class__.__name__)
+    return '.'.join(name)
+
+
+def remove_driver(notification_driver):
+    """Remove a notification driver at runtime."""
+    # Make sure the driver list is initialized.
+    _get_drivers()
+    removed = False
+    if notification_driver in drivers:
+        # We're removing an object.  Easy.
+        drivers.remove(notification_driver)
+        removed = True
+    else:
+        # We're removing a driver by name.  Search for it.
+        for driver in drivers:
+            if _object_name(driver) == notification_driver:
+                drivers.remove(driver)
+                removed = True
+
+    if not removed:
+        raise ValueError("Cannot remove; %s is not in list" %
+                         notification_driver)
+
+
+def notify(context, message):
+    """Passes notification to multiple notifiers in a list."""
+    for driver in _get_drivers():
+        try:
+            driver.notify(context, message)
+        except Exception as e:
+            LOG.exception(_("Problem '%(e)s' attempting to send to "
+                            "notification driver %(driver)s."), locals())
+
+
+def _reset_drivers():
+    """Used by unit tests to reset the drivers."""
+    global drivers
+    drivers = None

glance/openstack/common/notifier/log_notifier.py

@@ -0,0 +1,34 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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 glance.openstack.common import cfg
+from glance.openstack.common import jsonutils
+from glance.openstack.common import log as logging
+
+
+CONF = cfg.CONF
+
+
+def notify(_context, message):
+    """Notifies the recipient of the desired event given the model.
+    Log notifications using openstack's default logging system"""
+
+    priority = message.get('priority',
+                           CONF.default_notification_level)
+    priority = priority.lower()
+    logger = logging.getLogger(
+            'glance.openstack.common.notification.%s' % message['event_type'])
+    getattr(logger, priority)(jsonutils.dumps(message))

glance/openstack/common/notifier/no_op_notifier.py

@@ -0,0 +1,19 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+
+def notify(_context, message):
+    """Notifies the recipient of the desired event given the model"""
+    pass

glance/openstack/common/notifier/rabbit_notifier.py

@@ -0,0 +1,45 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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 glance.openstack.common import cfg
+from glance.openstack.common import context as req_context
+from glance.openstack.common import log as logging
+from glance.openstack.common import rpc
+
+LOG = logging.getLogger(__name__)
+
+notification_topic_opt = cfg.ListOpt('notification_topics',
+        default=['notifications', ],
+        help='AMQP topic used for openstack notifications')
+
+CONF = cfg.CONF
+CONF.register_opt(notification_topic_opt)
+
+
+def notify(context, message):
+    """Sends a notification to the RabbitMQ"""
+    if not context:
+        context = req_context.get_admin_context()
+    priority = message.get('priority',
+                           CONF.default_notification_level)
+    priority = priority.lower()
+    for topic in CONF.notification_topics:
+        topic = '%s.%s' % (topic, priority)
+        try:
+            rpc.notify(context, topic, message)
+        except Exception, e:
+            LOG.exception(_("Could not send notification to %(topic)s. "
+                            "Payload=%(message)s"), locals())

glance/openstack/common/notifier/test_notifier.py

@@ -0,0 +1,22 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+
+
+NOTIFICATIONS = []
+
+
+def notify(_context, message):
+    """Test notifier, stores notifications in memory for unittests."""
+    NOTIFICATIONS.append(message)