Source code for fedmsg.commands.hub
# This file is part of fedmsg.
# Copyright (C) 2012 Red Hat, Inc.
#
# fedmsg is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# fedmsg is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with fedmsg; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#
# Authors: Ralph Bean <rbean@redhat.com>
#
from gettext import gettext as _
import resource
from fedmsg.utils import load_class
from fedmsg.commands import BaseCommand
# Since many services use fedmsg-hubs, processes can exceed their resource
# limits on the number of open file descriptors. In the long term, apps should
# stop listening to every service, but as a short term fix an attempt is made
# to raise the resource limit here.
MAX_NOFILE = 4096
class HubCommand(BaseCommand):
""" Run the fedmsg hub.
``fedmsg-hub`` is the all-purpose daemon. This should be run on every host
that has services which declare their own consumers. ``fedmsg-hub`` will
listen to every endpoint discovered by :mod:`fedmsg.config` and forward
messages in-process to the locally-declared consumers. It is a thin
wrapper over a moksha-hub.
Other commands like ``fedmsg-irc`` are just specialized, restricted
versions of ``fedmsg-hub``. ``fedmsg-hub`` is the most general/abstract.
``fedmsg-hub`` also houses the functions to run a websocket server.
"""
name = 'fedmsg-hub'
extra_args = [
(['--with-consumers'], {
'dest': 'explicit_hub_consumers',
'type': str,
'help': 'A comma-delimited list of conumers to run.',
'default': None,
}),
(['--websocket-server-port'], {
'dest': 'moksha.livesocket.websocket.port',
'type': int,
'help': 'Port on which to host the websocket server.',
'default': None,
}),
]
def run(self):
# Check if the user wants the websocket server to run
if self.config['moksha.livesocket.websocket.port']:
self.config['moksha.livesocket.backend'] = 'websocket'
# If the user wants to override any consumers installed on the system
# and *only* run the ones they want to, they can do that.
consumers = None
if self.config['explicit_hub_consumers']:
locations = self.config['explicit_hub_consumers'].split(',')
locations = [load_class(location) for location in locations]
# Rephrase the fedmsg-config.py config as moksha *.ini format for
# zeromq. If we're not using zeromq (say, we're using STOMP), then just
# assume that the moksha configuration is specified correctly already
# in /etc/fedmsg.d/
if self.config.get('zmq_enabled', True):
moksha_options = dict(
zmq_subscribe_endpoints=','.join(
','.join(bunch) for bunch in self.config['endpoints'].values()
),
)
self.config.update(moksha_options)
self.set_rlimit_nofiles()
# Note that the hub we kick off here cannot send any message. You
# should use fedmsg.publish(...) still for that.
from moksha.hub import main
main(
# Pass in our config dict
options=self.config,
# Only run the specified consumers if any are so specified.
consumers=consumers,
# Tell moksha to quiet its logging.
framework=False,
)
def set_rlimit_nofiles(self, limit=MAX_NOFILE):
try:
msg = _(u'Setting RLIMIT_NOFILE to '
u'{max_files}').format(max_files=limit)
self.log.info(msg)
resource.setrlimit(
resource.RLIMIT_NOFILE, (limit, limit))
except (resource.error, ValueError) as e:
msg = _(u'Failed to raise the limit on the maximum number of open '
u'file descriptors to {max_files}: {err}')
self.log.warning(msg.format(max_files=limit, err=str(e)))
finally:
nofile = resource.getrlimit(resource.RLIMIT_NOFILE)
self.log.info(
_(u'RLIMIT_NOFILE is set to {nofile}').format(nofile=nofile))
[docs]def hub():
command = HubCommand()
command.execute()