307 lines
12 KiB
Python
307 lines
12 KiB
Python
# Copyright 2010 United States Government as represented by the
|
|
# Administrator of the National Aeronautics and Space Administration.
|
|
# All Rights Reserved.
|
|
#
|
|
# 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.
|
|
|
|
"""Metadata request handler."""
|
|
import hashlib
|
|
import hmac
|
|
import os
|
|
|
|
from oslo_log import log as logging
|
|
from oslo_utils import encodeutils
|
|
from oslo_utils import secretutils as secutils
|
|
import six
|
|
import webob.dec
|
|
import webob.exc
|
|
|
|
from nova.api.metadata import base
|
|
from nova.api import wsgi
|
|
from nova import cache_utils
|
|
import nova.conf
|
|
from nova import context as nova_context
|
|
from nova import exception
|
|
from nova.i18n import _
|
|
from nova.network.neutronv2 import api as neutronapi
|
|
|
|
CONF = nova.conf.CONF
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
class MetadataRequestHandler(wsgi.Application):
|
|
"""Serve metadata."""
|
|
|
|
def __init__(self):
|
|
self._cache = cache_utils.get_client(
|
|
expiration_time=CONF.api.metadata_cache_expiration)
|
|
if (CONF.neutron.service_metadata_proxy and
|
|
not CONF.neutron.metadata_proxy_shared_secret):
|
|
LOG.warning("metadata_proxy_shared_secret is not configured, "
|
|
"the metadata information returned by the proxy "
|
|
"cannot be trusted")
|
|
|
|
def get_metadata_by_remote_address(self, address):
|
|
if not address:
|
|
raise exception.FixedIpNotFoundForAddress(address=address)
|
|
|
|
cache_key = 'metadata-%s' % address
|
|
data = self._cache.get(cache_key)
|
|
if data:
|
|
LOG.debug("Using cached metadata for %s", address)
|
|
return data
|
|
|
|
try:
|
|
data = base.get_metadata_by_address(address)
|
|
except exception.NotFound:
|
|
return None
|
|
|
|
if CONF.api.metadata_cache_expiration > 0:
|
|
self._cache.set(cache_key, data)
|
|
|
|
return data
|
|
|
|
def get_metadata_by_instance_id(self, instance_id, address):
|
|
cache_key = 'metadata-%s' % instance_id
|
|
data = self._cache.get(cache_key)
|
|
if data:
|
|
LOG.debug("Using cached metadata for instance %s", instance_id)
|
|
return data
|
|
|
|
try:
|
|
data = base.get_metadata_by_instance_id(instance_id, address)
|
|
except exception.NotFound:
|
|
return None
|
|
|
|
if CONF.api.metadata_cache_expiration > 0:
|
|
self._cache.set(cache_key, data)
|
|
|
|
return data
|
|
|
|
@webob.dec.wsgify(RequestClass=wsgi.Request)
|
|
def __call__(self, req):
|
|
if os.path.normpath(req.path_info) == "/":
|
|
resp = base.ec2_md_print(base.VERSIONS + ["latest"])
|
|
req.response.body = encodeutils.to_utf8(resp)
|
|
req.response.content_type = base.MIME_TYPE_TEXT_PLAIN
|
|
return req.response
|
|
|
|
LOG.debug('Metadata request headers: %s', req.headers)
|
|
if CONF.neutron.service_metadata_proxy:
|
|
if req.headers.get('X-Metadata-Provider'):
|
|
meta_data = self._handle_instance_id_request_from_lb(req)
|
|
else:
|
|
meta_data = self._handle_instance_id_request(req)
|
|
else:
|
|
if req.headers.get('X-Instance-ID'):
|
|
LOG.warning(
|
|
"X-Instance-ID present in request headers. The "
|
|
"'service_metadata_proxy' option must be "
|
|
"enabled to process this header.")
|
|
meta_data = self._handle_remote_ip_request(req)
|
|
|
|
if meta_data is None:
|
|
raise webob.exc.HTTPNotFound()
|
|
|
|
try:
|
|
data = meta_data.lookup(req.path_info)
|
|
except base.InvalidMetadataPath:
|
|
raise webob.exc.HTTPNotFound()
|
|
|
|
if callable(data):
|
|
return data(req, meta_data)
|
|
|
|
resp = base.ec2_md_print(data)
|
|
req.response.body = encodeutils.to_utf8(resp)
|
|
|
|
req.response.content_type = meta_data.get_mimetype()
|
|
return req.response
|
|
|
|
def _handle_remote_ip_request(self, req):
|
|
remote_address = req.remote_addr
|
|
if CONF.api.use_forwarded_for:
|
|
remote_address = req.headers.get('X-Forwarded-For', remote_address)
|
|
|
|
try:
|
|
meta_data = self.get_metadata_by_remote_address(remote_address)
|
|
except Exception:
|
|
LOG.exception('Failed to get metadata for IP %s',
|
|
remote_address)
|
|
msg = _('An unknown error has occurred. '
|
|
'Please try your request again.')
|
|
raise webob.exc.HTTPInternalServerError(
|
|
explanation=six.text_type(msg))
|
|
|
|
if meta_data is None:
|
|
LOG.error('Failed to get metadata for IP %s: no metadata',
|
|
remote_address)
|
|
|
|
return meta_data
|
|
|
|
def _handle_instance_id_request(self, req):
|
|
instance_id = req.headers.get('X-Instance-ID')
|
|
tenant_id = req.headers.get('X-Tenant-ID')
|
|
signature = req.headers.get('X-Instance-ID-Signature')
|
|
remote_address = req.headers.get('X-Forwarded-For')
|
|
|
|
# Ensure that only one header was passed
|
|
|
|
if instance_id is None:
|
|
msg = _('X-Instance-ID header is missing from request.')
|
|
elif signature is None:
|
|
msg = _('X-Instance-ID-Signature header is missing from request.')
|
|
elif tenant_id is None:
|
|
msg = _('X-Tenant-ID header is missing from request.')
|
|
elif not isinstance(instance_id, six.string_types):
|
|
msg = _('Multiple X-Instance-ID headers found within request.')
|
|
elif not isinstance(tenant_id, six.string_types):
|
|
msg = _('Multiple X-Tenant-ID headers found within request.')
|
|
else:
|
|
msg = None
|
|
|
|
if msg:
|
|
raise webob.exc.HTTPBadRequest(explanation=msg)
|
|
|
|
self._validate_shared_secret(instance_id, signature,
|
|
remote_address)
|
|
|
|
return self._get_meta_by_instance_id(instance_id, tenant_id,
|
|
remote_address)
|
|
|
|
def _get_instance_id_from_lb(self, provider_id, instance_address):
|
|
# We use admin context, admin=True to lookup the
|
|
# inter-Edge network port
|
|
context = nova_context.get_admin_context()
|
|
neutron = neutronapi.get_client(context, admin=True)
|
|
|
|
# Tenant, instance ids are found in the following method:
|
|
# X-Metadata-Provider contains id of the metadata provider, and since
|
|
# overlapping networks cannot be connected to the same metadata
|
|
# provider, the combo of tenant's instance IP and the metadata
|
|
# provider has to be unique.
|
|
#
|
|
# The networks which are connected to the metadata provider are
|
|
# retrieved in the 1st call to neutron.list_subnets()
|
|
# In the 2nd call we read the ports which belong to any of the
|
|
# networks retrieved above, and have the X-Forwarded-For IP address.
|
|
# This combination has to be unique as explained above, and we can
|
|
# read the instance_id, tenant_id from that port entry.
|
|
|
|
# Retrieve networks which are connected to metadata provider
|
|
md_subnets = neutron.list_subnets(
|
|
context,
|
|
advanced_service_providers=[provider_id],
|
|
fields=['network_id'])
|
|
|
|
md_networks = [subnet['network_id']
|
|
for subnet in md_subnets['subnets']]
|
|
|
|
try:
|
|
# Retrieve the instance data from the instance's port
|
|
instance_data = neutron.list_ports(
|
|
context,
|
|
fixed_ips='ip_address=' + instance_address,
|
|
network_id=md_networks,
|
|
fields=['device_id', 'tenant_id'])['ports'][0]
|
|
except Exception as e:
|
|
LOG.error('Failed to get instance id for metadata '
|
|
'request, provider %(provider)s '
|
|
'networks %(networks)s '
|
|
'requester %(requester)s. Error: %(error)s',
|
|
{'provider': provider_id,
|
|
'networks': md_networks,
|
|
'requester': instance_address,
|
|
'error': e})
|
|
msg = _('An unknown error has occurred. '
|
|
'Please try your request again.')
|
|
raise webob.exc.HTTPBadRequest(explanation=msg)
|
|
|
|
instance_id = instance_data['device_id']
|
|
tenant_id = instance_data['tenant_id']
|
|
|
|
# instance_data is unicode-encoded, while cache_utils doesn't like
|
|
# that. Therefore we convert to str
|
|
if isinstance(instance_id, six.text_type):
|
|
instance_id = instance_id.encode('utf-8')
|
|
return instance_id, tenant_id
|
|
|
|
def _handle_instance_id_request_from_lb(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)
|
|
instance_address = remote_address.split(',')[0]
|
|
|
|
# If authentication token is set, authenticate
|
|
if CONF.neutron.metadata_proxy_shared_secret:
|
|
signature = req.headers.get('X-Metadata-Provider-Signature')
|
|
self._validate_shared_secret(provider_id, signature,
|
|
instance_address)
|
|
|
|
instance_id, tenant_id = self._get_instance_id_from_lb(
|
|
provider_id, instance_address)
|
|
LOG.debug('Instance %s with address %s matches provider %s',
|
|
instance_id, remote_address, provider_id)
|
|
return self._get_meta_by_instance_id(instance_id, tenant_id,
|
|
instance_address)
|
|
|
|
def _validate_shared_secret(self, requestor_id, signature,
|
|
requestor_address):
|
|
expected_signature = hmac.new(
|
|
encodeutils.to_utf8(CONF.neutron.metadata_proxy_shared_secret),
|
|
encodeutils.to_utf8(requestor_id),
|
|
hashlib.sha256).hexdigest()
|
|
|
|
if not secutils.constant_time_compare(expected_signature, signature):
|
|
if requestor_id:
|
|
LOG.warning('X-Instance-ID-Signature: %(signature)s does '
|
|
'not match the expected value: '
|
|
'%(expected_signature)s for id: '
|
|
'%(requestor_id)s. Request From: '
|
|
'%(requestor_address)s',
|
|
{'signature': signature,
|
|
'expected_signature': expected_signature,
|
|
'requestor_id': requestor_id,
|
|
'requestor_address': requestor_address})
|
|
|
|
msg = _('Invalid proxy request signature.')
|
|
raise webob.exc.HTTPForbidden(explanation=msg)
|
|
|
|
def _get_meta_by_instance_id(self, instance_id, tenant_id, remote_address):
|
|
try:
|
|
meta_data = self.get_metadata_by_instance_id(instance_id,
|
|
remote_address)
|
|
except Exception:
|
|
LOG.exception('Failed to get metadata for instance id: %s',
|
|
instance_id)
|
|
msg = _('An unknown error has occurred. '
|
|
'Please try your request again.')
|
|
raise webob.exc.HTTPInternalServerError(
|
|
explanation=six.text_type(msg))
|
|
|
|
if meta_data is None:
|
|
LOG.error('Failed to get metadata for instance id: %s',
|
|
instance_id)
|
|
elif meta_data.instance.project_id != tenant_id:
|
|
LOG.warning("Tenant_id %(tenant_id)s does not match tenant_id "
|
|
"of instance %(instance_id)s.",
|
|
{'tenant_id': tenant_id, 'instance_id': instance_id})
|
|
# causes a 404 to be raised
|
|
meta_data = None
|
|
|
|
return meta_data
|