deb-python-os-collect-config/os_collect_config/cfn.py
Steve Baker e5518c11c7 Set a timeout for all data fetches using requests
A timeout config value is added for each collector which uses requests
to fetch data, and this value is used for any requests calls.

Without a timeout a request may stall indefinitely and
os-collect-config will stop polling.

A timeout default of 10 seconds is chosen as the default. This is used
for both the connection timeout and the read timeout.

Change-Id: I4ad0065b5a85393105c6385a15653d7204b4f880
Closes-Bug: #1600652
2016-07-11 11:14:57 +12:00

144 lines
5.7 KiB
Python

# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
#
# 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
import os
from keystoneclient.contrib.ec2 import utils as ec2_utils
from lxml import etree
from oslo_config import cfg
from oslo_log import log
import six.moves.urllib.parse as urlparse
from os_collect_config import common
from os_collect_config import exc
from os_collect_config import merger
CONF = cfg.CONF
logger = log.getLogger(__name__)
opts = [
cfg.StrOpt('metadata-url',
help='URL to query for CloudFormation Metadata'),
cfg.StrOpt('heat-metadata-hint',
default='/var/lib/heat-cfntools/cfn-metadata-server',
help='Local file to read for metadata url if not explicitly '
' specified'),
cfg.StrOpt('ca_certificate', help='CA Certificate path'),
cfg.StrOpt('stack-name',
help='Stack name to describe'),
cfg.MultiStrOpt('path',
help='Path to Metadata'),
cfg.StrOpt('secret-access-key',
help='Secret Access Key'),
cfg.StrOpt('access-key-id',
help='Access Key ID'),
cfg.MultiStrOpt('deployment-key',
default=['deployments'],
help='DEPRECATED, use global configuration option '
'"deployment-key"'),
cfg.FloatOpt('timeout', default=10,
help='Seconds to wait for the connection and read request'
' timeout.')
]
name = 'cfn'
class Collector(object):
def __init__(self, requests_impl=common.requests):
self._requests_impl = requests_impl
self._session = requests_impl.Session()
def collect(self):
if CONF.cfn.metadata_url is None:
if (CONF.cfn.heat_metadata_hint
and os.path.exists(CONF.cfn.heat_metadata_hint)):
with open(CONF.cfn.heat_metadata_hint) as hint:
CONF.cfn.metadata_url = '%s/v1/' % hint.read().strip()
else:
logger.info('No metadata_url configured.')
raise exc.CfnMetadataNotConfigured
if CONF.cfn.access_key_id is None:
logger.info('No Access Key ID configured.')
raise exc.CfnMetadataNotConfigured
if CONF.cfn.secret_access_key is None:
logger.info('No Secret Access Key configured.')
raise exc.CfnMetadataNotConfigured
url = CONF.cfn.metadata_url
stack_name = CONF.cfn.stack_name
headers = {'Content-Type': 'application/json'}
final_content = {}
if CONF.cfn.path is None:
logger.info('No path configured')
raise exc.CfnMetadataNotConfigured
signer = ec2_utils.Ec2Signer(secret_key=CONF.cfn.secret_access_key)
for path in CONF.cfn.path:
if '.' not in path:
logger.error('Path not in format resource.field[.x.y] (%s)' %
path)
raise exc.CfnMetadataNotConfigured
resource, field = path.split('.', 1)
if '.' in field:
field, sub_path = field.split('.', 1)
else:
sub_path = ''
params = {'Action': 'DescribeStackResource',
'StackName': stack_name,
'LogicalResourceId': resource,
'AWSAccessKeyId': CONF.cfn.access_key_id,
'SignatureVersion': '2'}
parsed_url = urlparse.urlparse(url)
credentials = {'params': params,
'verb': 'GET',
'host': parsed_url.netloc,
'path': parsed_url.path}
params['Signature'] = signer.generate(credentials)
try:
content = self._session.get(
url, params=params, headers=headers,
verify=CONF.cfn.ca_certificate,
timeout=CONF.cfn.timeout)
content.raise_for_status()
except self._requests_impl.exceptions.RequestException as e:
logger.warn(e)
raise exc.CfnMetadataNotAvailable
map_content = etree.fromstring(content.text)
resource_detail = map_content.find(
'DescribeStackResourceResult').find('StackResourceDetail')
sub_element = resource_detail.find(field)
if sub_element is None:
logger.warn('Path %s does not exist.' % (path))
raise exc.CfnMetadataNotAvailable
try:
value = json.loads(sub_element.text)
except ValueError as e:
logger.warn(
'Path %s failed to parse as json. (%s)' % (path, e))
raise exc.CfnMetadataNotAvailable
if sub_path:
for subkey in sub_path.split('.'):
try:
value = value[subkey]
except KeyError:
logger.warn(
'Sub-key %s does not exist. (%s)' % (subkey, path))
raise exc.CfnMetadataNotAvailable
final_content.update(value)
final_list = merger.merged_list_from_content(
final_content, cfg.CONF.cfn.deployment_key, name)
return final_list