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# 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 calendar
import json
import time
from oslo_config import cfg
from oslo_log import log
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 metadata'),
cfg.FloatOpt('timeout', default=10,
help='Seconds to wait for the connection and read request'
' timeout.')
]
name = 'request'
class Collector:
def __init__(self, requests_impl=common.requests):
self._requests_impl = requests_impl
self._session = requests_impl.Session()
self.last_modified = None
def check_fetch_content(self, headers):
'''Raises RequestMetadataNotAvailable if metadata should not be
fetched.
'''
# no last-modified header, so fetch
lm = headers.get('last-modified')
if not lm:
return
last_modified = calendar.timegm(
time.strptime(lm, '%a, %d %b %Y %H:%M:%S %Z'))
# first run, so fetch
if not self.last_modified:
return last_modified
if last_modified < self.last_modified:
logger.warn(
'Last-Modified is older than previous collection')
if last_modified <= self.last_modified:
raise exc.RequestMetadataNotAvailable
return last_modified
def collect(self):
if CONF.request.metadata_url is None:
logger.info('No metadata_url configured.')
raise exc.RequestMetadataNotConfigured
url = CONF.request.metadata_url
timeout = CONF.request.timeout
final_content = {}
try:
head = self._session.head(url, timeout=timeout)
last_modified = self.check_fetch_content(head.headers)
content = self._session.get(url, timeout=timeout)
content.raise_for_status()
self.last_modified = last_modified
except self._requests_impl.exceptions.RequestException as e:
logger.warn(e)
raise exc.RequestMetadataNotAvailable
try:
value = json.loads(content.text)
except ValueError as e:
logger.warn(
'Failed to parse as json. (%s)' % e)
raise exc.RequestMetadataNotAvailable
final_content.update(value)
final_list = merger.merged_list_from_content(
final_content, cfg.CONF.deployment_key, name)
return final_list
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