kwapi/kwapi/plugins/__init__.py

61 lines
2.1 KiB
Python

# Author: François Rossigneux <francois.rossigneux@inria.fr>
#
# 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 json
from oslo.config import cfg
import zmq
from kwapi import security
from kwapi.openstack.common import log
LOG = log.getLogger(__name__)
def listen(function):
"""Subscribes to ZeroMQ messages, and adds received measurements to the
database. Messages are dictionaries dumped in JSON format.
"""
LOG.info('Listening to %s' % cfg.CONF.probes_endpoint)
context = zmq.Context.instance()
subscriber = context.socket(zmq.SUB)
if not cfg.CONF.watch_probe:
subscriber.setsockopt(zmq.SUBSCRIBE, '')
else:
for probe in cfg.CONF.watch_probe:
subscriber.setsockopt(zmq.SUBSCRIBE, probe + '.')
for endpoint in cfg.CONF.probes_endpoint:
subscriber.connect(endpoint)
while True:
[probe, message] = subscriber.recv_multipart()
measurements = json.loads(message)
if not isinstance(measurements, dict):
LOG.error('Bad message type (not a dict)')
elif cfg.CONF.signature_checking and \
not security.verify_signature(measurements,
cfg.CONF.driver_metering_secret):
LOG.error('Bad message signature')
else:
try:
probe = measurements['probe_id'].encode('utf-8')
function(probe, float(measurements['w']))
except (TypeError, ValueError):
LOG.error('Malformed power consumption data: %s'
% measurements['w'])
except KeyError:
LOG.error('Malformed message (missing required key)')