os-collect-config/os_collect_config/ec2.py
Steve Baker 76975f04e5 ec2 collector attempt config-drive before metadata server
This change will first attempt to get ec2 metadata from a v2 config
drive before falling back to the nova metadata server if no config
drive is detected.

Config drive is enabled in overcloud nodes, so using this for
os-collect-config will allow the undercloud nova metadata server to be
disabled.

V2 of the config-drive was released in OpenStack Folsom, so a decision
was made to not support V1 discovery at all. This makes the block
device candidate selection much simpler than the cloud-init one[1].

[1] https://git.launchpad.net/cloud-init/tree/cloudinit/sources/DataSourceConfigDrive.py#n219

Change-Id: I2aec0544fe40c2e901aee38c79bb838a627d20da
Closes-Bug: #1619074
2016-10-13 09:38:29 +13:00

81 lines
2.6 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 oslo_config import cfg
from oslo_log import log
from os_collect_config import cache
from os_collect_config import common
from os_collect_config import config_drive
from os_collect_config import exc
EC2_METADATA_URL = 'http://169.254.169.254/latest/meta-data'
CONF = cfg.CONF
opts = [
cfg.StrOpt('metadata-url',
default=EC2_METADATA_URL,
help='URL to query for EC2 Metadata'),
cfg.FloatOpt('timeout', default=10,
help='Seconds to wait for the connection and read request'
' timeout.')
]
name = 'ec2'
class Collector(object):
def __init__(self, requests_impl=common.requests):
self._requests_impl = requests_impl
self.session = requests_impl.Session()
def _fetch_metadata(self, fetch_url, timeout):
try:
r = self.session.get(fetch_url, timeout=timeout)
r.raise_for_status()
except self._requests_impl.exceptions.RequestException as e:
log.getLogger(__name__).warn(e)
raise exc.Ec2MetadataNotAvailable
content = r.text
if fetch_url[-1] == '/':
new_content = {}
for subkey in content.split("\n"):
if '=' in subkey:
subkey = subkey[:subkey.index('=')] + '/'
sub_fetch_url = fetch_url + subkey
if subkey[-1] == '/':
subkey = subkey[:-1]
new_content[subkey] = self._fetch_metadata(
sub_fetch_url, timeout)
content = new_content
return content
def collect(self):
cache_path = cache.get_path('ec2')
if os.path.exists(cache_path):
with open(cache_path) as f:
metadata = json.load(f)
if metadata:
return [('ec2', metadata)]
md = config_drive.get_metadata()
if md:
return [('ec2', md)]
root_url = '%s/' % (CONF.ec2.metadata_url)
return [('ec2', self._fetch_metadata(root_url, CONF.ec2.timeout))]