vmware-nsx/neutron/agent/linux/ovsdb_monitor.py
Salvatore Orlando 6a9f0ab42f Avoid processing ports which are not yet ready
This patch changes get_vif_port_set in order to not return
OVS ports for which the ofport is not yet assigned, thus avoiding
a regex match failure in get_vif_port_by_id.
Because of this failure, treat_vif_port is unable to wire
the port.
As get_vif_port_by_id is also used elsewhere in the agent, it has
been enhanced in order to tolerate situations in which ofport might
have not yet been assigned.

The ofport field is added to the list of those monitored by the
SimpleInterfaceMonitor. This will guarantee an event is generated
when the ofport is assigned to a port. Otherwise there is a risk
a port would be never processed if it was not yet ready the first
time is was detected. This change won't trigger any extra processing
on the agent side.

Finally, this patch avoids fetching device details from the plugin
for ports which have disappeared from the OVS bridge. This is a
little optimization which might be beneficial for short lived ports.

Change-Id: Icf7f0c7d6fe5239a358567cc9dc9db8ec11c15be
Partial-Bug: #1253896
2014-02-13 15:38:05 -08:00

115 lines
4.0 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2013 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 eventlet
from neutron.agent.linux import async_process
from neutron.openstack.common import log as logging
LOG = logging.getLogger(__name__)
class OvsdbMonitor(async_process.AsyncProcess):
"""Manages an invocation of 'ovsdb-client monitor'."""
def __init__(self, table_name, columns=None, format=None,
root_helper=None, respawn_interval=None):
cmd = ['ovsdb-client', 'monitor', table_name]
if columns:
cmd.append(','.join(columns))
if format:
cmd.append('--format=%s' % format)
super(OvsdbMonitor, self).__init__(cmd,
root_helper=root_helper,
respawn_interval=respawn_interval)
def _read_stdout(self):
data = self._process.stdout.readline()
if not data:
return
#TODO(marun) The default root helper outputs exit errors to
# stdout due to bug #1219530. This check can be moved to
# _read_stderr once the error is correctly output to stderr.
if self.root_helper and self.root_helper in data:
self._stderr_lines.put(data)
LOG.error(_('Error received from ovsdb monitor: %s') % data)
else:
self._stdout_lines.put(data)
LOG.debug(_('Output received from ovsdb monitor: %s') % data)
return data
def _read_stderr(self):
data = super(OvsdbMonitor, self)._read_stderr()
if data:
LOG.error(_('Error received from ovsdb monitor: %s') % data)
# Do not return value to ensure that stderr output will
# stop the monitor.
class SimpleInterfaceMonitor(OvsdbMonitor):
"""Monitors the Interface table of the local host's ovsdb for changes.
The has_updates() method indicates whether changes to the ovsdb
Interface table have been detected since the monitor started or
since the previous access.
"""
def __init__(self, root_helper=None, respawn_interval=None):
super(SimpleInterfaceMonitor, self).__init__(
'Interface',
columns=['name', 'ofport'],
format='json',
root_helper=root_helper,
respawn_interval=respawn_interval,
)
self.data_received = False
@property
def is_active(self):
return (self.data_received and
self._kill_event and
not self._kill_event.ready())
@property
def has_updates(self):
"""Indicate whether the ovsdb Interface table has been updated.
True will be returned if the monitor process is not active.
This 'failing open' minimizes the risk of falsely indicating
the absence of updates at the expense of potential false
positives.
"""
return bool(list(self.iter_stdout())) or not self.is_active
def start(self, block=False, timeout=5):
super(SimpleInterfaceMonitor, self).start()
if block:
eventlet.timeout.Timeout(timeout)
while not self.is_active:
eventlet.sleep()
def _kill(self, *args, **kwargs):
self.data_received = False
super(SimpleInterfaceMonitor, self)._kill(*args, **kwargs)
def _read_stdout(self):
data = super(SimpleInterfaceMonitor, self)._read_stdout()
if data and not self.data_received:
self.data_received = True
return data