ec2-api/ec2api/metadata/__init__.py
xuanyandong 44f22cf2a5 Remove six
Replace the following items with Python 3 style code.

- six.PY2
- six.text_type
- six.string_type
- six.binary_type
- six.iterkeys
- six.moves
- six.itervalues

Implements: blueprint six-removal

Change-Id: I6195ceeeed2ebe1586973eaeef7fa9f29698fec2
2022-07-05 17:37:44 +08:00

285 lines
11 KiB
Python

# Copyright 2014
# The Cloudscaling Group, Inc.
#
# 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 hashlib
import hmac
import posixpath
import httplib2
from oslo_cache import core as cache_core
from oslo_config import cfg
from oslo_log import log as logging
import urllib.parse as urlparse
import webob
from ec2api import context as ec2_context
from ec2api import exception
from ec2api.i18n import _
from ec2api.metadata import api
from ec2api import utils
from ec2api import wsgi
LOG = logging.getLogger(__name__)
CONF = cfg.CONF
CONF.import_opt('use_forwarded_for', 'ec2api.api.auth')
metadata_opts = [
cfg.StrOpt('nova_metadata_ip',
default='127.0.0.1',
help=_("IP address used by Nova metadata server.")),
cfg.IntOpt('nova_metadata_port',
default=8775,
help=_("TCP Port used by Nova metadata server.")),
cfg.StrOpt('nova_metadata_protocol',
default='http',
choices=['http', 'https'],
help=_("Protocol to access nova metadata, http or https")),
cfg.BoolOpt('nova_metadata_insecure',
default=False,
help=_("Allow to perform insecure SSL (https) requests to "
"nova metadata")),
cfg.StrOpt('auth_ca_cert',
help=_("Certificate Authority public key (CA cert) "
"file for ssl")),
cfg.StrOpt('nova_client_cert',
default='',
help=_("Client certificate for nova metadata api server.")),
cfg.StrOpt('nova_client_priv_key',
default='',
help=_("Private key of client certificate.")),
cfg.StrOpt('metadata_proxy_shared_secret',
default='',
help=_('Shared secret to sign instance-id request'),
secret=True),
cfg.IntOpt("cache_expiration",
default=15,
min=0,
help=_('This option is the time (in seconds) to cache metadata. '
'Increasing this setting should improve response times of the '
'metadata API when under heavy load. Higher values may '
'increase memory usage, and result in longer times for host '
'metadata changes to take effect.'))
]
CONF.register_opts(metadata_opts, group='metadata')
cache_core.configure(CONF)
class MetadataRequestHandler(wsgi.Application):
"""Serve metadata."""
def __init__(self):
if not CONF.cache.enabled:
LOG.warning("Metadata doesn't use cache. "
"Configure cache options to use cache.")
self.cache_region = cache_core.create_region()
cache_core.configure_cache_region(CONF, self.cache_region)
@webob.dec.wsgify(RequestClass=wsgi.Request)
def __call__(self, req):
LOG.debug('Request: %s', req)
path = req.path_info
if path == '' or path[0] != '/':
path = '/' + path
path = posixpath.normpath(path)
path_tokens = path.split('/')[1:]
if path_tokens[0] == 'ec2':
path_tokens = path_tokens[1:]
if path_tokens == ['']:
resp = api.get_version_list()
return self._add_response_data(req.response, resp)
try:
requester = self._get_requester(req)
if path_tokens[0] == 'openstack':
return self._proxy_request(req, requester)
resp = self._get_metadata(path_tokens, requester)
return self._add_response_data(req.response, resp)
except exception.EC2MetadataNotFound:
return webob.exc.HTTPNotFound()
except Exception:
LOG.exception("Unexpected error.")
msg = _('An unknown error has occurred. '
'Please try your request again.')
return webob.exc.HTTPInternalServerError(
explanation=str(msg))
def _proxy_request(self, req, requester):
headers = self._build_proxy_request_headers(requester)
nova_ip_port = '%s:%s' % (CONF.metadata.nova_metadata_ip,
CONF.metadata.nova_metadata_port)
url = urlparse.urlunsplit((
CONF.metadata.nova_metadata_protocol,
nova_ip_port,
req.path_info,
req.query_string,
''))
h = httplib2.Http(
ca_certs=CONF.metadata.auth_ca_cert,
disable_ssl_certificate_validation=(
CONF.metadata.nova_metadata_insecure)
)
if (CONF.metadata.nova_client_cert and
CONF.metadata.nova_client_priv_key):
h.add_certificate(CONF.metadata.nova_client_priv_key,
CONF.metadata.nova_client_cert,
nova_ip_port)
resp, content = h.request(url, method=req.method, headers=headers,
body=req.body)
if resp.status == 200:
LOG.debug(str(resp))
req.response.content_type = resp['content-type']
req.response.body = content
return req.response
elif resp.status == 403:
LOG.warning(
'The remote metadata server responded with Forbidden. This '
'response usually occurs when shared secrets do not match.'
)
return webob.exc.HTTPForbidden()
elif resp.status == 400:
return webob.exc.HTTPBadRequest()
elif resp.status == 404:
return webob.exc.HTTPNotFound()
elif resp.status == 409:
return webob.exc.HTTPConflict()
elif resp.status == 500:
msg = _(
'Remote metadata server experienced an internal server error.'
)
LOG.warning(msg)
return webob.exc.HTTPInternalServerError(
explanation=str(msg))
else:
raise Exception(_('Unexpected response code: %s') % resp.status)
def _build_proxy_request_headers(self, requester):
signature = self._sign_instance_id(requester['os_instance_id'])
return {
'X-Forwarded-For': requester['private_ip'],
'X-Instance-ID': requester['os_instance_id'],
'X-Tenant-ID': requester['project_id'],
'X-Instance-ID-Signature': signature,
}
def _sign_instance_id(self, instance_id):
return hmac.new(
CONF.metadata.metadata_proxy_shared_secret.encode("utf-8"),
instance_id.encode(),
hashlib.sha256).hexdigest()
def _get_requester(self, req):
if req.headers.get('X-Metadata-Provider'):
provider_id, remote_ip = self._unpack_nsx_request(req)
context = ec2_context.get_os_admin_context()
os_instance_id, project_id = (
api.get_os_instance_and_project_id_by_provider_id(
context, provider_id, remote_ip))
else:
os_instance_id, project_id, remote_ip = (
self._unpack_neutron_request(req))
return {'os_instance_id': os_instance_id,
'project_id': project_id,
'private_ip': remote_ip}
def _unpack_neutron_request(self, req):
os_instance_id = req.headers.get('X-Instance-ID')
project_id = req.headers.get('X-Tenant-ID')
signature = req.headers.get('X-Instance-ID-Signature')
remote_ip = req.headers.get('X-Forwarded-For')
if not remote_ip:
raise exception.EC2MetadataInvalidAddress()
if os_instance_id is None:
msg = _('X-Instance-ID header is missing from request.')
elif project_id is None:
msg = _('X-Tenant-ID header is missing from request.')
elif not isinstance(os_instance_id, str):
msg = _('Multiple X-Instance-ID headers found within request.')
elif not isinstance(project_id, str):
msg = _('Multiple X-Tenant-ID headers found within request.')
else:
msg = None
if msg:
raise webob.exc.HTTPBadRequest(explanation=msg)
self._validate_signature(signature, os_instance_id, remote_ip)
return os_instance_id, project_id, remote_ip
def _unpack_nsx_request(self, req):
remote_address = req.headers.get('X-Forwarded-For')
if remote_address is None:
msg = _('X-Forwarded-For is missing from request.')
raise webob.exc.HTTPBadRequest(explanation=msg)
provider_id = req.headers.get('X-Metadata-Provider')
if provider_id is None:
msg = _('X-Metadata-Provider is missing from request.')
raise webob.exc.HTTPBadRequest(explanation=msg)
remote_ip = remote_address.split(',')[0]
if CONF.metadata.metadata_proxy_shared_secret:
signature = req.headers.get('X-Metadata-Provider-Signature')
self._validate_signature(signature, provider_id, remote_ip)
return provider_id, remote_ip
def _validate_signature(self, signature, requester_id, requester_ip):
expected_signature = hmac.new(
CONF.metadata.metadata_proxy_shared_secret.encode("utf-8"),
requester_id.encode(),
hashlib.sha256).hexdigest()
if not (signature and
utils.constant_time_compare(expected_signature, signature)):
LOG.warning('X-Instance-ID-Signature: %(signature)s does '
'not match the expected value: '
'%(expected_signature)s for id: '
'%(requester_id)s. Request From: '
'%(requester_ip)s',
{'signature': signature,
'expected_signature': expected_signature,
'requester_id': requester_id,
'requester_ip': requester_ip})
msg = _('Invalid proxy request signature.')
raise webob.exc.HTTPForbidden(explanation=msg)
def _get_metadata(self, path_tokens, requester):
context = ec2_context.get_os_admin_context()
# NOTE(ft): substitute project_id for context to instance's one.
# It's needed for correct describe and auto update DB operations.
# It doesn't affect operations via OpenStack's clients because
# these clients use auth_token field only
context.project_id = requester['project_id']
return api.get_metadata_item(context, path_tokens,
requester['os_instance_id'],
requester['private_ip'],
self.cache_region)
def _add_response_data(self, response, data):
if isinstance(data, str):
response.text = data
else:
response.body = data
response.content_type = 'text/plain'
return response