Synnefo » snf-ganeti

#!/usr/bin/python

#

# 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 SocketServer

import threading

import time

import collections

import Queue

import random

import signal

import simplejson

from cStringIO import StringIO

from ganeti import constants

from ganeti import mcpu

from ganeti import opcodes

from ganeti import jqueue

from ganeti import luxi

from ganeti import utils

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 = 1

  def __init__(self, address, rqhandler):

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

    self.do_quit = False

    self.queue = jqueue.QueueManager()

    self.processors = []

    for i in range(self.QUEUE_PROCESSOR_SIZE):

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

                                              args=(i, self.queue.new_queue)))

    for t in self.processors:

      t.start()

    signal.signal(signal.SIGINT, self.handle_sigint)

  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_sigint(self, signum, frame):

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

    self.do_quit = True

    self.server_close()

    for i in range(self.QUEUE_PROCESSOR_SIZE):

      self.queue.new_queue.put(None)

  def serve_forever(self):

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

    while not self.do_quit:

      self.handle_request()

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):

  """Job executor.

  This functions processes a single job in the context of given

  processor instance.

  """

  job.SetStatus(opcodes.Job.STATUS_RUNNING)

  for op in job.data.op_list:

    proc.ExecOpCode(op)

  job.SetStatus(opcodes.Job.STATUS_FINISHED, result=opcodes.Job.RESULT_OK)

def PoolWorker(worker_id, incoming_queue):

  """A worker thread function.

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

  """

  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(feedback=lambda x: None)

      try:

        JobRunner(proc, item)

      except errors.GenericError, err:

        print "ganeti exception %s" % err

    finally:

      utils.Unlock('cmd')

      utils.LockCleanup()

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

  print "worker %s exiting" % worker_id

def main():

  """Main function"""

  master = IOServer(constants.MASTER_SOCKET, ClientRqHandler)

  master.serve_forever()

if __name__ == "__main__":

  main()