Synnefo » snf-ganeti

#!/usr/bin/python -u

#

# Copyright (C) 2006, 2007 Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program 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

# General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Master daemon program.

Some classes deviates from the standard style guide since the

inheritance from parent classes requires it.

"""

import sys

import SocketServer

import threading

import time

import collections

import Queue

import random

import signal

import simplejson

from cStringIO import StringIO

from optparse import OptionParser

from ganeti import config

from ganeti import constants

from ganeti import mcpu

from ganeti import opcodes

from ganeti import jqueue

from ganeti import locking

from ganeti import luxi

from ganeti import utils

from ganeti import errors

from ganeti import ssconf

EXIT_NOTMASTER = constants.EXIT_NOTMASTER

EXIT_NODESETUP_ERROR = constants.EXIT_NODESETUP_ERROR

class IOServer(SocketServer.UnixStreamServer):

  """IO thread class.

  This class takes care of initializing the other threads, setting

  signal handlers (which are processed only in this thread), and doing

  cleanup at shutdown.

  """

  QUEUE_PROCESSOR_SIZE = 5

  def __init__(self, address, rqhandler, context):

    """IOServer constructor

    Args:

      address: the address to bind this IOServer to

      rqhandler: RequestHandler type object

      context: Context Object common to all worker threads

    """

    SocketServer.UnixStreamServer.__init__(self, address, rqhandler)

    self.do_quit = False

    self.queue = jqueue.QueueManager()

    self.context = context

    self.processors = []

    signal.signal(signal.SIGINT, self.handle_quit_signals)

    signal.signal(signal.SIGTERM, self.handle_quit_signals)

  def setup_processors(self):

    """Spawn the processors threads.

    This initializes the queue and the thread processors. It is done

    separately from the constructor because we want the clone()

    syscalls to happen after the daemonize part.

    """

    for i in range(self.QUEUE_PROCESSOR_SIZE):

      self.processors.append(threading.Thread(target=PoolWorker,

                                              args=(i, self.queue.new_queue,

                                                    self.context)))

    for t in self.processors:

      t.start()

  def process_request_thread(self, request, client_address):

    """Process the request.

    This is copied from the code in ThreadingMixIn.

    """

    try:

      self.finish_request(request, client_address)

      self.close_request(request)

    except:

      self.handle_error(request, client_address)

      self.close_request(request)

  def process_request(self, request, client_address):

    """Start a new thread to process the request.

    This is copied from the coode in ThreadingMixIn.

    """

    t = threading.Thread(target=self.process_request_thread,

                         args=(request, client_address))

    t.start()

  def handle_quit_signals(self, signum, frame):

    print "received %s in %s" % (signum, frame)

    self.do_quit = True

  def serve_forever(self):

    """Handle one request at a time until told to quit."""

    while not self.do_quit:

      self.handle_request()

      print "served request, quit=%s" % (self.do_quit)

  def server_cleanup(self):

    """Cleanup the server.

    This involves shutting down the processor threads and the master

    socket.

    """

    self.server_close()

    utils.RemoveFile(constants.MASTER_SOCKET)

    for i in range(self.QUEUE_PROCESSOR_SIZE):

      self.queue.new_queue.put(None)

    for idx, t in enumerate(self.processors):

      print "waiting for processor thread %s..." % idx

      t.join()

    print "done threads"

class ClientRqHandler(SocketServer.BaseRequestHandler):

  """Client handler"""

  EOM = '\3'

  READ_SIZE = 4096

  def setup(self):

    self._buffer = ""

    self._msgs = collections.deque()

    self._ops = ClientOps(self.server)

  def handle(self):

    while True:

      msg = self.read_message()

      if msg is None:

        print "client closed connection"

        break

      request = simplejson.loads(msg)

      if not isinstance(request, dict):

        print "wrong request received: %s" % msg

        break

      method = request.get('request', None)

      data = request.get('data', None)

      if method is None or data is None:

        print "no method or data in request"

        break

      print "request:", method, data

      result = self._ops.handle_request(method, data)

      print "result:", result

      self.send_message(simplejson.dumps({'success': True, 'result': result}))

  def read_message(self):

    while not self._msgs:

      data = self.request.recv(self.READ_SIZE)

      if not data:

        return None

      new_msgs = (self._buffer + data).split(self.EOM)

      self._buffer = new_msgs.pop()

      self._msgs.extend(new_msgs)

    return self._msgs.popleft()

  def send_message(self, msg):

    #print "sending", msg

    self.request.sendall(msg + self.EOM)

class ClientOps:

  """Class holding high-level client operations."""

  def __init__(self, server):

    self.server = server

    self._cpu = None

  def _getcpu(self):

    if self._cpu is None:

      self._cpu = mcpu.Processor(lambda x: None)

    return self._cpu

  def handle_request(self, operation, args):

    print operation, args

    if operation == "submit":

      return self.put(args)

    elif operation == "query":

      return self.query(args)

    else:

      raise ValueError("Invalid operation")

  def put(self, args):

    job = luxi.UnserializeJob(args)

    rid = self.server.queue.put(job)

    return rid

  def query(self, args):

    path = args["object"]

    fields = args["fields"]

    names = args["names"]

    if path == "instances":

      opclass = opcodes.OpQueryInstances

    elif path == "jobs":

      # early exit because job query-ing is special (not via opcodes)

      return self.query_jobs(fields, names)

    else:

      raise ValueError("Invalid object %s" % path)

    op = opclass(output_fields = fields, names=names)

    cpu = self._getcpu()

    result = cpu.ExecOpCode(op)

    return result

  def query_jobs(self, fields, names):

    return self.server.queue.query_jobs(fields, names)

def JobRunner(proc, job, context):

  """Job executor.

  This functions processes a single job in the context of given

  processor instance.

  Args:

    proc: Ganeti Processor to run the job on

    job: The job to run (unserialized format)

    context: Ganeti shared context

  """

  job.SetStatus(opcodes.Job.STATUS_RUNNING)

  fail = False

  for idx, op in enumerate(job.data.op_list):

    job.data.op_status[idx] = opcodes.Job.STATUS_RUNNING

    try:

      job.data.op_result[idx] = proc.ExecOpCode(op)

      job.data.op_status[idx] = opcodes.Job.STATUS_SUCCESS

    except (errors.OpPrereqError, errors.OpExecError), err:

      fail = True

      job.data.op_result[idx] = str(err)

      job.data.op_status[idx] = opcodes.Job.STATUS_FAIL

  if fail:

    job.SetStatus(opcodes.Job.STATUS_FAIL)

  else:

    job.SetStatus(opcodes.Job.STATUS_SUCCESS)

def PoolWorker(worker_id, incoming_queue, context):

  """A worker thread function.

  This is the actual processor of a single thread of Job execution.

  Args:

    worker_id: the unique id for this worker

    incoming_queue: a queue to get jobs from

    context: the common server context, containing all shared data and

             synchronization structures.

  """

  while True:

    print "worker %s sleeping" % worker_id

    item = incoming_queue.get(True)

    if item is None:

      break

    print "worker %s processing job %s" % (worker_id, item.data.job_id)

    #utils.Lock('cmd')

    try:

      proc = mcpu.Processor(context, feedback=lambda x: None)

      try:

        JobRunner(proc, item, context)

      except errors.GenericError, err:

        msg = "ganeti exception %s" % err

        item.SetStatus(opcodes.Job.STATUS_FAIL, result=[msg])

        print msg

      except Exception, err:

        msg = "unhandled exception %s" % err

        item.SetStatus(opcodes.Job.STATUS_FAIL, result=[msg])

        print msg

      except:

        msg = "unhandled unknown exception"

        item.SetStatus(opcodes.Job.STATUS_FAIL, result=[msg])

        print msg

    finally:

      #utils.Unlock('cmd')

      #utils.LockCleanup()

      pass

    print "worker %s finish job %s" % (worker_id, item.data.job_id)

  print "worker %s exiting" % worker_id

class GanetiContext(object):

  """Context common to all ganeti threads.

  This class creates and holds common objects shared by all threads.

  """

  _instance = None

  def __init__(self):

    """Constructs a new GanetiContext object.

    There should be only a GanetiContext object at any time, so this

    function raises an error if this is not the case.

    """

    assert self.__class__._instance is None, "double GanetiContext instance"

    # Create a ConfigWriter...

    self.cfg = config.ConfigWriter()

    # And a GanetiLockingManager...

    self.GLM = locking.GanetiLockManager(

                self.cfg.GetNodeList(),

                self.cfg.GetInstanceList())

    # setting this also locks the class against attribute modifications

    self.__class__._instance = self

  def __setattr__(self, name, value):

    """Setting GanetiContext attributes is forbidden after initialization.

    """

    assert self.__class__._instance is None, "Attempt to modify Ganeti Context"

    object.__setattr__(self, name, value)

def CheckMaster(debug):

  """Checks the node setup.

  If this is the master, the function will return. Otherwise it will

  exit with an exit code based on the node status.

  """

  try:

    ss = ssconf.SimpleStore()

    master_name = ss.GetMasterNode()

  except errors.ConfigurationError, err:

    print "Cluster configuration incomplete: '%s'" % str(err)

    sys.exit(EXIT_NODESETUP_ERROR)

  try:

    myself = utils.HostInfo()

  except errors.ResolverError, err:

    sys.stderr.write("Cannot resolve my own name (%s)\n" % err.args[0])

    sys.exit(EXIT_NODESETUP_ERROR)

  if myself.name != master_name:

    if debug:

      sys.stderr.write("Not master, exiting.\n")

    sys.exit(EXIT_NOTMASTER)

def ParseOptions():

  """Parse the command line options.

  Returns:

    (options, args) as from OptionParser.parse_args()

  """

  parser = OptionParser(description="Ganeti master daemon",

                        usage="%prog [-f] [-d]",

                        version="%%prog (ganeti) %s" %

                        constants.RELEASE_VERSION)

  parser.add_option("-f", "--foreground", dest="fork",

                    help="Don't detach from the current terminal",

                    default=True, action="store_false")

  parser.add_option("-d", "--debug", dest="debug",

                    help="Enable some debug messages",

                    default=False, action="store_true")

  options, args = parser.parse_args()

  return options, args

def main():

  """Main function"""

  options, args = ParseOptions()

  utils.debug = options.debug

  utils.no_fork = True

  CheckMaster(options.debug)

  master = IOServer(constants.MASTER_SOCKET, ClientRqHandler, GanetiContext())

  # become a daemon

  if options.fork:

    utils.Daemonize(logfile=constants.LOG_MASTERDAEMON,

                    noclose_fds=[master.fileno()])

  try:

    utils.Lock('cmd', debug=options.debug)

  except errors.LockError, err:

    print >> sys.stderr, str(err)

    master.server_cleanup()

    return

  try:

    master.setup_processors()

    try:

      master.serve_forever()

    finally:

      master.server_cleanup()

  finally:

    utils.Unlock('cmd')

    utils.LockCleanup()

if __name__ == "__main__":

  main()