aodh/ceilometer/collector/meter.py
Julien Danjou 51c8a8e55c Update pep8 to 1.3.3
This is needed to update openstack.common

Change-Id: I8410f978f38b3893b71239f97f785086ca5faffe
Signed-off-by: Julien Danjou <julien@danjou.info>
2013-01-15 14:39:29 +01:00

102 lines
3.2 KiB
Python

# -*- encoding: utf-8 -*-
#
# Copyright © 2012 New Dream Network, LLC (DreamHost)
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
#
# 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.
"""Compute the signature of a metering message.
"""
import hashlib
import hmac
import uuid
from ceilometer.openstack.common import cfg
METER_OPTS = [
cfg.StrOpt('metering_secret',
default='change this or be hacked',
help='Secret value for signing metering messages',
),
cfg.StrOpt('counter_source',
default='openstack',
help='Source for counters emited on this instance',
),
]
def register_opts(config):
"""Register the options for signing metering messages.
"""
config.register_opts(METER_OPTS)
register_opts(cfg.CONF)
def recursive_keypairs(d):
"""Generator that produces sequence of keypairs for nested dictionaries.
"""
for name, value in sorted(d.iteritems()):
if isinstance(value, dict):
for subname, subvalue in recursive_keypairs(value):
yield ('%s:%s' % (name, subname), subvalue)
else:
yield name, value
def compute_signature(message, secret):
"""Return the signature for a message dictionary.
"""
digest_maker = hmac.new(secret, '', hashlib.sha256)
for name, value in recursive_keypairs(message):
if name == 'message_signature':
# Skip any existing signature value, which would not have
# been part of the original message.
continue
digest_maker.update(name)
digest_maker.update(unicode(value).encode('utf-8'))
return digest_maker.hexdigest()
def verify_signature(message, secret):
"""Check the signature in the message against the value computed
from the rest of the contents.
"""
old_sig = message.get('message_signature')
new_sig = compute_signature(message, secret)
return new_sig == old_sig
def meter_message_from_counter(counter, secret, source):
"""Make a metering message ready to be published or stored.
Returns a dictionary containing a metering message
for a notification message and a Counter instance.
"""
msg = {'source': source,
'counter_name': counter.name,
'counter_type': counter.type,
'counter_unit': counter.unit,
'counter_volume': counter.volume,
'user_id': counter.user_id,
'project_id': counter.project_id,
'resource_id': counter.resource_id,
'timestamp': counter.timestamp,
'resource_metadata': counter.resource_metadata,
'message_id': str(uuid.uuid1()),
}
msg['message_signature'] = compute_signature(msg, secret)
return msg