/usr/lib/python3/dist-packages/ClusterShell/Gateway.py is in python3-clustershell 1.8-1.
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# Copyright (C) 2010-2016 CEA/DAM
# Copyright (C) 2010-2011 Henri Doreau <henri.doreau@cea.fr>
# Copyright (C) 2015-2017 Stephane Thiell <sthiell@stanford.edu>
#
# This file is part of ClusterShell.
#
# ClusterShell 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.
#
# ClusterShell 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 ClusterShell; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""
ClusterShell agent launched on remote gateway nodes. This script reads messages
on stdin via the SSH connection, interprets them, takes decisions, and prints
out replies on stdout.
"""
import logging
import os
import sys
import traceback
from ClusterShell.Event import EventHandler
from ClusterShell.NodeSet import NodeSet
from ClusterShell.Task import task_self, _getshorthostname
from ClusterShell.Engine.Engine import EngineAbortException
from ClusterShell.Worker.fastsubprocess import set_nonblock_flag
from ClusterShell.Worker.Worker import StreamWorker, FANOUT_UNLIMITED
from ClusterShell.Worker.Tree import TreeWorker
from ClusterShell.Communication import Channel, ConfigurationMessage, \
ControlMessage, ACKMessage, ErrorMessage, StartMessage, EndMessage, \
StdOutMessage, StdErrMessage, RetcodeMessage, TimeoutMessage, \
MessageProcessingError
def _gw_print_debug(task, line):
"""Default gateway task debug printing function"""
logging.getLogger(__name__).debug(line)
def gateway_excepthook(exc_type, exc_value, tb):
"""
Default excepthook for Gateway to redirect any unhandled exception
to logger instead of stderr.
"""
tbexc = traceback.format_exception(exc_type, exc_value, tb)
logging.getLogger(__name__).error(''.join(tbexc))
class TreeWorkerResponder(EventHandler):
"""Gateway TreeWorker handler"""
def __init__(self, task, gwchan, srcwkr):
EventHandler.__init__(self)
self.gwchan = gwchan # gateway channel
self.srcwkr = srcwkr # id of distant parent TreeWorker
self.worker = None # local TreeWorker instance
self.retcodes = {} # self-managed retcodes
self.logger = logging.getLogger(__name__)
# Grooming initialization
self.timer = None
qdelay = task.info("grooming_delay")
if qdelay > 1.0e-3:
# Enable messages and rc grooming - enable msgtree (#181)
task.set_default("stdout_msgtree", True)
task.set_default("stderr_msgtree", True)
# create auto-closing timer object for grooming
self.timer = task.timer(qdelay, self, qdelay, autoclose=True)
self.logger.debug("TreeWorkerResponder initialized grooming=%f", qdelay)
def ev_start(self, worker):
self.logger.debug("TreeWorkerResponder: ev_start")
self.worker = worker
def ev_timer(self, timer):
"""perform gateway traffic grooming"""
if not self.worker:
return
logger = self.logger
# check for grooming opportunities for stdout/stderr
for msg_elem, nodes in self.worker.iter_errors():
logger.debug("iter(stderr): %s: %d bytes", nodes,
len(msg_elem.message()))
self.gwchan.send(StdErrMessage(nodes, msg_elem.message(),
self.srcwkr))
for msg_elem, nodes in self.worker.iter_buffers():
logger.debug("iter(stdout): %s: %d bytes", nodes,
len(msg_elem.message()))
self.gwchan.send(StdOutMessage(nodes, msg_elem.message(),
self.srcwkr))
# empty internal MsgTree buffers
self.worker.flush_buffers()
self.worker.flush_errors()
# specifically manage retcodes to periodically return latest
# retcodes to parent node, instead of doing it at ev_hup (no msg
# aggregation) or at ev_close (no parent node live updates)
for rc, nodes in self.retcodes.items():
self.logger.debug("iter(rc): %s: rc=%d", nodes, rc)
self.gwchan.send(RetcodeMessage(nodes, rc, self.srcwkr))
self.retcodes.clear()
def ev_read(self, worker, node, sname, msg):
"""message received"""
if sname == worker.SNAME_STDOUT:
msg_class = StdOutMessage
elif sname == worker.SNAME_STDERR:
msg_class = StdErrMessage
self.logger.debug("TreeWorkerResponder: ev_error %s %s", node, msg)
if self.timer is None:
self.gwchan.send(msg_class(node, msg, self.srcwkr))
def ev_hup(self, worker, node, rc):
"""Received end of command from one node"""
if self.timer is None:
self.gwchan.send(RetcodeMessage(node, rc, self.srcwkr))
else:
# retcode grooming
if rc in self.retcodes:
self.retcodes[rc].add(node)
else:
self.retcodes[rc] = NodeSet(node)
def ev_close(self, worker, timedout):
"""End of CTL responder"""
self.logger.debug("TreeWorkerResponder: ev_close timedout=%s", timedout)
if timedout:
# some nodes did timeout
msg = TimeoutMessage(NodeSet._fromlist1(worker.iter_keys_timeout()),
self.srcwkr)
self.gwchan.send(msg)
if self.timer is not None:
# finalize grooming
self.ev_timer(None)
self.timer.invalidate()
class GatewayChannel(Channel):
"""high level logic for gateways"""
def __init__(self, task):
Channel.__init__(self, error_response=True)
self.task = task
self.nodename = None
self.topology = None
self.propagation = None
self.logger = logging.getLogger(__name__)
def start(self):
"""initialization"""
# prepare communication
self._init()
self.logger.debug('ready to accept channel communication')
def close(self):
"""close gw channel"""
self.logger.debug('closing gateway channel')
self._close()
def recv(self, msg):
"""handle incoming message"""
try:
self.logger.debug('handling incoming message: %s', str(msg))
if msg.type == EndMessage.ident:
self.logger.debug('recv: got EndMessage')
self._close()
elif self.setup:
self.recv_ctl(msg)
elif self.opened:
self.recv_cfg(msg)
elif msg.type == StartMessage.ident:
self.logger.debug('got start message %s', msg)
self.opened = True
self._open()
self.logger.debug('channel started (version %s on remote end)',
self._xml_reader.version)
else:
self.logger.error('unexpected message: %s', str(msg))
raise MessageProcessingError('unexpected message: %s' % msg)
except MessageProcessingError as ex:
self.logger.error('on recv(): %s', str(ex))
self.send(ErrorMessage(str(ex)))
self._close()
except EngineAbortException:
# gateway task abort: don't handle like other exceptions
raise
except Exception as ex:
self.logger.exception('on recv(): %s', str(ex))
self.send(ErrorMessage(str(ex)))
self._close()
def recv_cfg(self, msg):
"""receive cfg/topology configuration"""
if msg.type != ConfigurationMessage.ident:
raise MessageProcessingError('unexpected message: %s' % msg)
self.logger.debug('got channel configuration')
# gw node name
hostname = _getshorthostname()
if not msg.gateway:
self.nodename = hostname
self.logger.warn('gw name not provided, using system hostname %s',
self.nodename)
else:
self.nodename = msg.gateway
self.logger.debug('using gateway node name %s', self.nodename)
if self.nodename.lower() != hostname.lower():
self.logger.debug('gw name %s does not match system hostname %s',
self.nodename, hostname)
# topology
task_self().topology = self.topology = msg.data_decode()
self.logger.debug('decoded propagation tree')
self.logger.debug('\n%s', self.topology)
self.setup = True
self._ack(msg)
def recv_ctl(self, msg):
"""receive control message with actions to perform"""
if msg.type == ControlMessage.ident:
self.logger.debug('GatewayChannel._state_ctl')
if msg.action == 'shell':
data = msg.data_decode()
cmd = data['cmd']
stderr = data['stderr']
timeout = data['timeout']
remote = data['remote']
#self.propagation.invoke_gateway = data['invoke_gateway']
self.logger.debug('decoded gw invoke (%s)',
data['invoke_gateway'])
taskinfo = data['taskinfo']
self.logger.debug('assigning task infos (%s)', data['taskinfo'])
task = task_self()
task._info.update(taskinfo)
task.set_info('print_debug', _gw_print_debug)
if task.info('debug'):
self.logger.setLevel(logging.DEBUG)
self.logger.debug('inherited fanout value=%d',
task.info("fanout"))
self.logger.debug('launching execution/enter gathering state')
responder = TreeWorkerResponder(task, self, msg.srcid)
self.propagation = TreeWorker(msg.target, responder, timeout,
command=cmd,
topology=self.topology,
newroot=self.nodename,
stderr=stderr,
remote=remote)
# FIXME ev_start-not-called workaround
responder.worker = self.propagation
self.propagation.upchannel = self
task.schedule(self.propagation)
self.logger.debug("TreeWorker scheduled")
self._ack(msg)
elif msg.action == 'write':
data = msg.data_decode()
self.logger.debug('GatewayChannel write: %d bytes',
len(data['buf']))
self.propagation.write(data['buf'])
self._ack(msg)
elif msg.action == 'eof':
self.logger.debug('GatewayChannel eof')
self.propagation.set_write_eof()
self._ack(msg)
else:
self.logger.error('unexpected CTL action: %s', msg.action)
else:
self.logger.error('unexpected message: %s', str(msg))
def _ack(self, msg):
"""acknowledge a received message"""
self.send(ACKMessage(msg.msgid))
def ev_close(self, worker, timedout):
"""Gateway (parent) channel is closing.
We abort the whole gateway task to stop other running workers.
This avoids any unwanted remaining processes on gateways.
"""
self.logger.debug('GatewayChannel: ev_close')
self.worker.task.abort()
def gateway_main():
"""ClusterShell gateway entry point"""
host = _getshorthostname()
# configure root logger
logdir = os.path.expanduser(os.environ.get('CLUSTERSHELL_GW_LOG_DIR',
'/tmp'))
loglevel = os.environ.get('CLUSTERSHELL_GW_LOG_LEVEL', 'INFO')
try:
log_level = getattr(logging, loglevel.upper(), logging.INFO)
log_fmt = '%(asctime)s %(name)s %(levelname)s %(message)s'
logging.basicConfig(level=log_level, format=log_fmt,
filename=os.path.join(logdir, "%s.gw.log" % host))
except (IOError, OSError):
pass # logging failure is not fatal
logger = logging.getLogger(__name__)
sys.excepthook = gateway_excepthook
logger.debug('Starting gateway on %s', host)
logger.debug("environ=%s", os.environ)
set_nonblock_flag(sys.stdin.fileno())
set_nonblock_flag(sys.stdout.fileno())
set_nonblock_flag(sys.stderr.fileno())
task = task_self()
# Disable MsgTree buffering, it is enabled later when needed
task.set_default("stdout_msgtree", False)
task.set_default("stderr_msgtree", False)
if sys.stdin.isatty():
logger.critical('Gateway failure: sys.stdin.isatty() is True')
sys.exit(1)
gateway = GatewayChannel(task)
worker = StreamWorker(handler=gateway)
# Define worker._fanout to not rely on the engine's fanout, and use
# the special value FANOUT_UNLIMITED to always allow registration
worker._fanout = FANOUT_UNLIMITED
worker.set_reader(gateway.SNAME_READER, sys.stdin)
worker.set_writer(gateway.SNAME_WRITER, sys.stdout, retain=False)
# must stay disabled for now (see #274)
#worker.set_writer(gateway.SNAME_ERROR, sys.stderr, retain=False)
task.schedule(worker)
logger.debug('Starting task')
try:
task.resume()
logger.debug('Task performed')
except EngineAbortException as exc:
logger.debug('EngineAbortException')
except IOError as exc:
logger.debug('Broken pipe (%s)', exc)
raise
except Exception as exc:
logger.exception('Gateway failure: %s', exc)
logger.debug('-------- The End --------')
if __name__ == '__main__':
__name__ = 'ClusterShell.Gateway'
# To enable gateway profiling:
#import cProfile
#cProfile.run('gateway_main()', '/tmp/gwprof')
gateway_main()
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