openstack/neutron
Code Issues Proposed changes

Merge "[eventlet-deprecation] Implement a metadata proxy without eventlet"

Browse Source
This commit is contained in:
Zuul 2025-01-20 13:29:16 +00:00 committed by Gerrit Code Review
commit fff7e0b2f7
11 changed files with 290 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
doc/source/eventlet_deprecation/index.rst
View File

@ -26,3 +26,39 @@ Eventlet Deprecation Reference
This document contains the information related to the ``eventlet`` library
deprecation. Each section describes how each module has been migrated, the
caveats, the pending technical debt and the missing parts.
OVN Agent
---------
Launch process
~~~~~~~~~~~~~~
The execution of the OVN agent has been replaced. Instead of using
``oslo_services.launch``, that is still using eventlet, the agent creates
a ``threading.Event`` instance and holds the main thread execution by waiting
for this event.
.. note::
Once the ``oslo_services`` library removes the usage of
eventlet, the previous implementation will be restored. The
``oslo_services.service.ProcessLauncher`` service launcher implements a
signal handler.
Metadata proxy
~~~~~~~~~~~~~~
The ``UnixDomainWSGIServer`` class has been replaced with a new implementation.
This implementation does not rely on ``neutron.api.wsgi.Server`` nor
``eventlet.wsgi.server``. It inherits from the built-in library class
``socketserver.StreamRequestHandler``.
.. note::
This implementation doesn't use ``oslo_services`` to spawn the
processes or the local threads depending on the ``metadata_workers``
configuration variable. Right now only the embedded form (local thread)
is implemented (``metadata_workers=0``, the default value). Future
implementations will enable again this configuration variable.

4
neutron/agent/metadata/proxy_base.py
View File

@ -17,7 +17,6 @@ import abc
import urllib
import netaddr
from neutron_lib import constants
from oslo_log import log as logging
from oslo_utils import netutils
@ -43,9 +42,10 @@ class MetadataProxyHandlerBase(metaclass=abc.ABCMeta):
NETWORK_ID_HEADER: str
ROUTER_ID_HEADER: str
def __init__(self, conf, has_cache=False):
def __init__(self, conf, has_cache=False, **kwargs):
self.conf = conf
self._has_cache = has_cache
super().__init__(**kwargs)
@abc.abstractmethod
def get_port(self, remote_address, network_id=None, remote_mac=None,

8
neutron/agent/ovn/agent/ovn_neutron_agent.py
View File

@ -13,6 +13,7 @@
# License for the specific language governing permissions and limitations
# under the License.
import threading
import uuid
from oslo_log import log as logging
@ -159,6 +160,13 @@ class OVNNeutronAgent(service.Service):
self.ext_manager_api.nb_idl = self._load_nb_idl()
self.ext_manager.start()
LOG.info('OVN Neutron Agent started')
self.wait()
def wait(self):
# TODO(ralonsoh): remove this forced wait when the oslo_service.service
# implementation is restored in the OVN agent main method.
event = threading.Event()
event.wait()
def stop(self, graceful=True):
LOG.info('Stopping OVN Neutron Agent')

6
neutron/agent/ovn/extensions/metadata.py
View File

@ -24,7 +24,7 @@ from ovsdbapp.backend.ovs_idl import vlog
from neutron.agent.linux import external_process
from neutron.agent.ovn.extensions import extension_manager
from neutron.agent.ovn.metadata import agent as metadata_agent
from neutron.agent.ovn.metadata import server as metadata_server
from neutron.agent.ovn.metadata import server_socket as metadata_server
from neutron.common.ovn import constants as ovn_const
from neutron.conf.agent.database import agents_db
from neutron.conf.agent.metadata import config as meta_conf
@ -178,5 +178,9 @@ class MetadataExtension(extension_manager.OVNAgentExtension,
# Register the agent with its corresponding Chassis
self.register_metadata_agent()
# Start the metadata server.
proxy_thread = threading.Thread(target=self._proxy.wait)
proxy_thread.start()
# Raise the "is_started" flag.
self._is_started = True

9
neutron/agent/ovn/metadata/server.py
View File

@ -14,16 +14,17 @@
import threading
from neutron.agent.linux import utils as agent_utils
from neutron.agent.metadata import proxy_base
from neutron.agent.ovn.metadata import ovsdb
from neutron.common.ovn import constants as ovn_const
from neutron_lib.callbacks import events
from neutron_lib.callbacks import registry
from neutron_lib.callbacks import resources
from oslo_config import cfg
from oslo_log import log as logging
from neutron.agent.linux import utils as agent_utils
from neutron.agent.metadata import proxy_base
from neutron.agent.ovn.metadata import ovsdb
from neutron.common.ovn import constants as ovn_const
LOG = logging.getLogger(__name__)

218
neutron/agent/ovn/metadata/server_socket.py Normal file
View File

@ -0,0 +1,218 @@
# Copyright 2025 Red Hat, 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 io
import socketserver
import urllib
import jinja2
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import encodeutils
import requests
import webob
from webob import exc as webob_exc
from neutron._i18n import _
from neutron.agent.linux import utils as agent_utils
from neutron.agent.metadata import proxy_base
from neutron.common import ipv6_utils
from neutron.common.ovn import constants as ovn_const
from neutron.common import utils as common_utils
LOG = logging.getLogger(__name__)
RESPONSE = jinja2.Template("""HTTP/1.1 {{ http_code }}
Content-Type: text/plain; charset=UTF-8
Connection: close
Content-Length: {{ len }}
<html>
<head>
<title>{{ title }}</title>
</head>
<body>
<h1>{{ body_title }}</h1>
{{ body }}<br /><br />
</body>
</html>""")
RESPONSE_LENGHT = 40
class MetadataProxyHandlerBaseSocketServer(
proxy_base.MetadataProxyHandlerBase):
@staticmethod
def _http_response(http_response, request):
_res = webob.Response(
body=http_response.content,
headerlist=list(http_response.headers.items()),
status=http_response.status_code,
content_type=http_response.headers['content-type'],
charset=http_response.encoding)
# NOTE(ralonsoh): there should be a better way to format the HTTP
# response, adding the HTTP version to the ``webob.Response``
# output string.
out = request.http_version + ' ' + str(_res)
return out.encode(http_response.encoding)
def _proxy_request(self, instance_id, project_id, req):
headers = {
'X-Forwarded-For': req.headers.get('X-Forwarded-For'),
'X-Instance-ID': instance_id,
'X-Tenant-ID': project_id,
'X-Instance-ID-Signature': common_utils.sign_instance_id(
self.conf, instance_id)
}
nova_host_port = ipv6_utils.valid_ipv6_url(
self.conf.nova_metadata_host,
self.conf.nova_metadata_port)
url = urllib.parse.urlunsplit((
self.conf.nova_metadata_protocol,
nova_host_port,
req.path_info,
req.query_string,
''))
disable_ssl_certificate_validation = self.conf.nova_metadata_insecure
if self.conf.auth_ca_cert and not disable_ssl_certificate_validation:
verify_cert = self.conf.auth_ca_cert
else:
verify_cert = not disable_ssl_certificate_validation
client_cert = None
if self.conf.nova_client_cert and self.conf.nova_client_priv_key:
client_cert = (self.conf.nova_client_cert,
self.conf.nova_client_priv_key)
try:
resp = requests.request(method=req.method, url=url,
headers=headers,
data=req.body,
cert=client_cert,
verify=verify_cert,
timeout=60)
except requests.ConnectionError:
msg = _('The remote metadata server is temporarily unavailable. '
'Please try again later.')
LOG.warning(msg)
title = '503 Service Unavailable'
length = RESPONSE_LENGHT + len(title) * 2 + len(msg)
reponse = RESPONSE.render(http_code=title, title=title,
body_title=title, body=title, len=length)
return encodeutils.to_utf8(reponse)
if resp.status_code == 200:
return self._http_response(resp, req)
if resp.status_code == 403:
LOG.warning(
'The remote metadata server responded with Forbidden. This '
'response usually occurs when shared secrets do not match.'
)
# TODO(ralonsoh): add info in the returned HTTP message to the VM.
return self._http_response(resp, req)
if resp.status_code == 500:
msg = _(
'Remote metadata server experienced an internal server error.'
)
LOG.warning(msg)
# TODO(ralonsoh): add info in the returned HTTP message to the VM.
return self._http_response(resp, req)
if resp.status_code in (400, 404, 409, 502, 503, 504):
# TODO(ralonsoh): add info in the returned HTTP message to the VM.
return self._http_response(resp, req)
raise Exception(_('Unexpected response code: %s') % resp.status_code)
class MetadataProxyHandler(MetadataProxyHandlerBaseSocketServer,
socketserver.StreamRequestHandler):
NETWORK_ID_HEADER = 'X-OVN-Network-ID'
ROUTER_ID_HEADER = ''
_conf = None
_chassis = None
_sb_idl = None
def __init__(self, request, client_address, server):
super().__init__(self._conf, has_cache=False, request=request,
client_address=client_address, server=server)
def handle(self):
try:
request = self.request.recv(4096)
LOG.debug('Request: %s', request.decode('utf-8'))
f_request = io.BytesIO(request)
req = webob.Request.from_file(f_request)
instance_id, project_id = self._get_instance_and_project_id(req)
if instance_id:
res = self._proxy_request(instance_id, project_id, req)
self.wfile.write(res)
return
# TODO(ralonsoh): change this return to be a formatted Request
# and added to self.wfile
return webob_exc.HTTPNotFound()
except Exception as exc:
LOG.exception('Error while receiving data.')
raise exc
@property
def sb_idl(self):
return self._sb_idl
def get_port(self, remote_address, network_id=None, remote_mac=None,
router_id=None, skip_cache=False):
ports = self.sb_idl.get_network_port_bindings_by_ip(network_id,
remote_address,
mac=remote_mac)
num_ports = len(ports)
if num_ports == 1:
external_ids = ports[0].external_ids
return (external_ids[ovn_const.OVN_DEVID_EXT_ID_KEY],
external_ids[ovn_const.OVN_PROJID_EXT_ID_KEY])
if num_ports == 0:
LOG.error("No port found in network %s with IP address %s",
network_id, remote_address)
elif num_ports > 1:
port_uuids = ', '.join([str(port.uuid) for port in ports])
LOG.error("More than one port found in network %s with IP address "
"%s. Please run the neutron-ovn-db-sync-util script as "
"there seems to be inconsistent data between Neutron "
"and OVN databases. OVN Port uuids: %s", network_id,
remote_address, port_uuids)
return None, None
class UnixDomainMetadataProxy(proxy_base.UnixDomainMetadataProxyBase):
def __init__(self, conf, chassis, sb_idl=None):
super().__init__(conf)
self.chassis = chassis
self.sb_idl = sb_idl
agent_utils.ensure_directory_exists_without_file(
cfg.CONF.metadata_proxy_socket)
self._server = None
def run(self):
file_socket = cfg.CONF.metadata_proxy_socket
self._server = socketserver.ThreadingUnixStreamServer(
file_socket, MetadataProxyHandler)
MetadataProxyHandler._conf = self.conf
MetadataProxyHandler._chassis = self.chassis
MetadataProxyHandler._sb_idl = self.sb_idl
def wait(self):
self._server.serve_forever()

9
neutron/agent/ovn/ovn_neutron_agent.py
View File

@ -20,7 +20,6 @@ from neutron.common import utils
from neutron.conf import common as common_config
from oslo_config import cfg
from oslo_log import log as logging
from oslo_service import service
from neutron.agent.ovn.agent import ovn_neutron_agent
from neutron.conf.agent.ovn.ovn_neutron_agent import config as config_ovn_agent
@ -44,5 +43,9 @@ def main():
ovn_agent = ovn_neutron_agent.OVNNeutronAgent(cfg.CONF)
LOG.info('OVN Neutron Agent initialized successfully, now running... ')
launcher = service.launch(cfg.CONF, ovn_agent, restart_method='mutate')
launcher.wait()
# NOTE(ralonsoh): restore the oslo_service.service implementation once
# the eventlet removal is done; it handles the system signals properly
# (TERM, HUP, INT).
# launcher = service.launch(cfg.CONF, ovn_agent, restart_method='mutate')
# launcher.wait()
ovn_agent.start()

0
neutron/cmd/agents/__init__.py Normal file
View File

0
neutron/cmd/eventlet/agents/ovn_neutron_agent.py → neutron/cmd/agents/ovn_neutron_agent.py
View File

11
neutron/tests/functional/agent/ovn/agent/test_ovn_neutron_agent.py
View File

@ -22,6 +22,7 @@ from oslo_utils import uuidutils
from neutron.agent.ovn.agent import ovn_neutron_agent
from neutron.agent.ovn.agent import ovsdb as agent_ovsdb
from neutron.agent.ovn.metadata import agent as metadata_agent
from neutron.agent.ovn.metadata import server_socket
from neutron.common.ovn import constants as ovn_const
from neutron.common import utils as n_utils
from neutron.tests.common import net_helpers
@ -69,7 +70,13 @@ class TestOVNNeutronAgentBase(base.TestOVNFunctionalBase):
agt.test_ovs_idl = []
agt.test_ovn_sb_idl = []
agt.test_ovn_nb_idl = []
agt.start()
# NOTE(ralonsoh): it is needed to ``UnixDomainMetadataProxy.wait``
# method in eventlet environments in order not to block the execution.
# Once eventlet is completely removed, this mock can be deleted.
with mock.patch.object(ovn_neutron_agent.OVNNeutronAgent, 'wait'), \
mock.patch.object(server_socket.UnixDomainMetadataProxy,
'wait'):
agt.start()
self._check_loaded_and_started_extensions(agt)
self.addCleanup(agt.ext_manager_api.ovs_idl.ovsdb_connection.stop)
@ -127,4 +134,4 @@ class TestOVNNeutronAgentMetadataExtension(TestOVNNeutronAgentBase):
# Check Unix proxy is running.
metadata_extension = self.ovn_agent[METADATA_EXTENSION]
self.assertIsNotNone(metadata_extension._proxy.server)
self.assertIsNotNone(metadata_extension._proxy._server)

2
setup.cfg
View File

@ -56,7 +56,7 @@ console_scripts =
neutron-sanity-check = neutron.cmd.sanity_check:main
neutron-periodic-workers = neutron.cmd.eventlet.server:main_periodic_eventlet
neutron-status = neutron.cmd.status:main
neutron-ovn-agent = neutron.cmd.eventlet.agents.ovn_neutron_agent:main
neutron-ovn-agent = neutron.cmd.agents.ovn_neutron_agent:main
neutron-ovn-maintenance-worker = neutron.cmd.eventlet.server:main_ovn_maintenance_eventlet
neutron-ovn-metadata-agent = neutron.cmd.eventlet.agents.ovn_metadata:main
neutron-ovn-migration-mtu = neutron.cmd.ovn.migration_mtu:main