deb-ceilometer/ceilometer/hardware/plugin.py
Nejc Saje b6e1c7e5dc Migrate the rest of the central agent pollsters to use discoveries
Currently, not all the central agent pollsters use discoveries.
In order to enable horizontal scaling, all pollsters must use
discoveries so the resources can be partitioned across the pool
of running central agents.

For pollsters that don't poll specific resources, but only poll
general info from services, we treat the service endpoints as
resources. So in the case of Glance, there will be only one
resource available for all the pollsters (a Glance endpoint).
If there are multiple agents running, only one will be assigned
that endpoint and only one will poll Glance API.

DocImpact
Co-Authored-By: Dina Belova <dbelova@mirantis.com>
Closes-Bug: #1364352
Change-Id: I8f3b228db9aacf3a7cc4b719c50013cc30d5aa79
2014-09-08 13:38:10 -04:00

113 lines
4.1 KiB
Python

#
# Copyright 2013 ZHAW SoE
# Copyright 2014 Intel Corp.
#
# Authors: Lucas Graf <graflu0@students.zhaw.ch>
# Toni Zehnder <zehndton@students.zhaw.ch>
# Lianhao Lu <lianhao.lu@intel.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.
"""Base class for plugins used by the hardware agent."""
import abc
import itertools
from oslo.utils import netutils
import six
from ceilometer.central import plugin
from ceilometer.hardware import inspector as insloader
from ceilometer.openstack.common.gettextutils import _
from ceilometer.openstack.common import log
LOG = log.getLogger(__name__)
@six.add_metaclass(abc.ABCMeta)
class HardwarePollster(plugin.CentralPollster):
"""Base class for plugins that support the polling API."""
CACHE_KEY = None
IDENTIFIER = None
def __init__(self):
super(HardwarePollster, self).__init__()
self.inspectors = {}
@property
def default_discovery(self):
return 'tripleo_overcloud_nodes'
def get_samples(self, manager, cache, resources):
"""Return an iterable of Sample instances from polling the resources.
:param manager: The service manager invoking the plugin
:param cache: A dictionary for passing data between plugins
:param resources: end point to poll data from
"""
resources = resources or []
h_cache = cache.setdefault(self.CACHE_KEY, {})
sample_iters = []
for res in resources:
parsed_url = netutils.urlsplit(res)
ins = self._get_inspector(parsed_url)
try:
# Call hardware inspector to poll for the data
i_cache = h_cache.setdefault(res, {})
if self.IDENTIFIER not in i_cache:
i_cache[self.IDENTIFIER] = list(ins.inspect_generic(
parsed_url,
self.IDENTIFIER,
i_cache))
# Generate samples
if i_cache[self.IDENTIFIER]:
sample_iters.append(self.generate_samples(
parsed_url,
i_cache[self.IDENTIFIER]))
except Exception as err:
LOG.exception(_('inspector call failed for %(ident)s '
'host %(host)s: %(err)s'),
dict(ident=self.IDENTIFIER,
host=parsed_url.hostname,
err=err))
return itertools.chain(*sample_iters)
def generate_samples(self, host_url, data):
"""Generate an iterable Sample from the data returned by inspector
:param host_url: host url of the endpoint
:param data: list of data returned by the corresponding inspector
"""
return (self.generate_one_sample(host_url, datum) for datum in data)
@abc.abstractmethod
def generate_one_sample(self, host_url, c_data):
"""Return one Sample.
:param host_url: host url of the endpoint
:param c_data: data returned by the inspector.inspect_generic,
tuple of (value, metadata, extra)
"""
def _get_inspector(self, parsed_url):
if parsed_url.scheme not in self.inspectors:
try:
driver = insloader.get_inspector(parsed_url)
self.inspectors[parsed_url.scheme] = driver
except Exception as err:
LOG.exception(_("Can NOT load inspector %(name)s: %(err)s"),
dict(name=parsed_url.scheme,
err=err))
raise err
return self.inspectors[parsed_url.scheme]