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 time

import collections

import Queue

import random

import signal

import simplejson

import logging

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

from ganeti import logger

from ganeti import workerpool

CLIENT_REQUEST_WORKERS = 16

EXIT_NOTMASTER = constants.EXIT_NOTMASTER

EXIT_NODESETUP_ERROR = constants.EXIT_NODESETUP_ERROR

class ClientRequestWorker(workerpool.BaseWorker):

  def RunTask(self, server, request, client_address):

    """Process the request.

    This is copied from the code in ThreadingMixIn.

    """

    try:

      server.finish_request(request, client_address)

      server.close_request(request)

    except:

      server.handle_error(request, client_address)

      server.close_request(request)

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.

  """

  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.context = context

    # We'll only start threads once we've forked.

    self.jobqueue = None

    self.request_workers = None

  def setup_queue(self):

    self.jobqueue = jqueue.JobQueue(self.context)

    self.request_workers = workerpool.WorkerPool(CLIENT_REQUEST_WORKERS,

                                                 ClientRequestWorker)

  def process_request(self, request, client_address):

    """Add task to workerpool to process request.

    """

    self.request_workers.AddTask(self, request, client_address)

  def serve_forever(self):

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

    sighandler = utils.SignalHandler([signal.SIGINT, signal.SIGTERM])

    try:

      while not sighandler.called:

        self.handle_request()

    finally:

      sighandler.Reset()

  def server_cleanup(self):

    """Cleanup the server.

    This involves shutting down the processor threads and the master

    socket.

    """

    try:

      self.server_close()

      utils.RemoveFile(constants.MASTER_SOCKET)

    finally:

      if self.request_workers:

        self.request_workers.TerminateWorkers()

      if self.jobqueue:

        self.jobqueue.Shutdown()

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:

        logging.info("client closed connection")

        break

      request = simplejson.loads(msg)

      logging.debug("request: %s", request)

      if not isinstance(request, dict):

        logging.error("wrong request received: %s", msg)

        break

      method = request.get(luxi.KEY_METHOD, None)

      args = request.get(luxi.KEY_ARGS, None)

      if method is None or args is None:

        logging.error("no method or args in request")

        break

      success = False

      try:

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

        success = True

      except:

        logging.error("Unexpected exception", exc_info=True)

        err = sys.exc_info()

        result = "Caught exception: %s" % str(err[1])

      response = {

        luxi.KEY_SUCCESS: success,

        luxi.KEY_RESULT: result,

        }

      logging.debug("response: %s", response)

      self.send_message(simplejson.dumps(response))

  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

  def handle_request(self, method, args):

    queue = self.server.jobqueue

    # TODO: Parameter validation

    if method == luxi.REQ_SUBMIT_JOB:

      ops = [opcodes.OpCode.LoadOpCode(state) for state in args]

      # we need to compute the node list here, since from now on all

      # operations require locks on the queue or the storage, and we

      # shouldn't get another lock

      node_list = self.server.context.cfg.GetNodeList()

      return queue.SubmitJob(ops, node_list)

    elif method == luxi.REQ_CANCEL_JOB:

      job_id = args

      return queue.CancelJob(job_id)

    elif method == luxi.REQ_ARCHIVE_JOB:

      job_id = args

      return queue.ArchiveJob(job_id)

    elif method == luxi.REQ_QUERY_JOBS:

      (job_ids, fields) = args

      return queue.QueryJobs(job_ids, fields)

    else:

      raise ValueError("Invalid operation")

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()])

  utils.WritePidFile(constants.MASTERD_PID)

  logger.SetupDaemon(constants.LOG_MASTERDAEMON, debug=options.debug,

                     stderr_logging=not options.fork)

  logging.info("ganeti master daemon startup")

  master.setup_queue()

  try:

    master.serve_forever()

  finally:

    master.server_cleanup()

    utils.RemovePidFile(constants.MASTERD_PID)

if __name__ == "__main__":

  main()