text: #
  # Copyright 2013-2014 eNovance
  #
  # Author: Mehdi Abaakouk <mehdi.abaakouk@enovance.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.
  """Rest alarm notifier."""
  
  import eventlet
  from oslo.config import cfg
  from oslo.serialization import jsonutils
  import requests
  import six.moves.urllib.parse as urlparse
  
  from ceilometer.alarm import notifier
  from ceilometer.openstack.common import context
  from ceilometer.openstack.common.gettextutils import _
  from ceilometer.openstack.common import log
  
  LOG = log.getLogger(__name__)
  
  REST_NOTIFIER_OPTS = [
      cfg.StrOpt('rest_notifier_certificate_file',
                 default='',
                 help='SSL Client certificate for REST notifier.'
                 ),
      cfg.StrOpt('rest_notifier_certificate_key',
                 default='',
                 help='SSL Client private key for REST notifier.'
                 ),
      cfg.BoolOpt('rest_notifier_ssl_verify',
                  default=True,
                  help='Whether to verify the SSL Server certificate when '
                  'calling alarm action.'
                  ),
      cfg.IntOpt('rest_notifier_max_retries',
                 default=0,
                 help='Number of retries for REST notifier',
                 ),
  
  ]
  
  cfg.CONF.register_opts(REST_NOTIFIER_OPTS, group="alarm")
  
  
  class RestAlarmNotifier(notifier.AlarmNotifier):
      """Rest alarm notifier."""
  
      @staticmethod
      def notify(action, alarm_id, previous, current, reason, reason_data,
                 headers=None):
          headers = headers or {}
          if not headers.get('x-openstack-request-id'):
              headers['x-openstack-request-id'] = context.generate_request_id()
  
          LOG.info(_(
              "Notifying alarm %(alarm_id)s from %(previous)s "
              "to %(current)s with action %(action)s because "
              "%(reason)s. request-id: %(request_id)s") %
              ({'alarm_id': alarm_id, 'previous': previous,
                'current': current, 'action': action,
                'reason': reason,
                'request_id': headers['x-openstack-request-id']}))
          body = {'alarm_id': alarm_id, 'previous': previous,
                  'current': current, 'reason': reason,
                  'reason_data': reason_data}
          headers['content-type'] = 'application/json'
          kwargs = {'data': jsonutils.dumps(body),
                    'headers': headers}
  
          if action.scheme == 'https':
              default_verify = int(cfg.CONF.alarm.rest_notifier_ssl_verify)
              options = urlparse.parse_qs(action.query)
              verify = bool(int(options.get('ceilometer-alarm-ssl-verify',
                                            [default_verify])[-1]))
              kwargs['verify'] = verify
  
              cert = cfg.CONF.alarm.rest_notifier_certificate_file
              key = cfg.CONF.alarm.rest_notifier_certificate_key
              if cert:
                  kwargs['cert'] = (cert, key) if key else cert
  
          # FIXME(rhonjo): Retries are automatically done by urllib3 in requests
          # library. However, there's no interval between retries in urllib3
          # implementation. It will be better to put some interval between
          # retries (future work).
          max_retries = cfg.CONF.alarm.rest_notifier_max_retries
          session = requests.Session()
          session.mount(action.geturl(),
                        requests.adapters.HTTPAdapter(max_retries=max_retries))
          eventlet.spawn_n(session.post, action.geturl(), **kwargs)
  