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+      #
+      #
       # 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.
       """Functions used by the node daemon"""
       import os
       import os.path
       import shutil
       import time
       import stat
       import errno
       import re
       import subprocess
       import random
       import logging
       import tempfile
       from ganeti import errors
       from ganeti import utils
       from ganeti import ssh
       from ganeti import hypervisor
       from ganeti import constants
       from ganeti import bdev
       from ganeti import objects
       from ganeti import ssconf
       def _GetConfig():
         return ssconf.SimpleConfigReader()
       def _GetSshRunner():
         return ssh.SshRunner(_GetConfig())
       def _CleanDirectory(path, exclude=[]):
         """Removes all regular files in a directory.
         @param exclude: List of files to be excluded.
         @type exclude: list
         """
         if not os.path.isdir(path):
           return
         # Normalize excluded paths
         exclude = [os.path.normpath(i) for i in exclude]
         for rel_name in utils.ListVisibleFiles(path):
           full_name = os.path.normpath(os.path.join(path, rel_name))
           if full_name in exclude:
             continue
           if os.path.isfile(full_name) and not os.path.islink(full_name):
             utils.RemoveFile(full_name)
       def JobQueuePurge():
         """Removes job queue files and archived jobs
         """
         _CleanDirectory(constants.QUEUE_DIR, exclude=[constants.JOB_QUEUE_LOCK_FILE])
         _CleanDirectory(constants.JOB_QUEUE_ARCHIVE_DIR)
       def GetMasterInfo():
         """Returns master information.
         This is an utility function to compute master information, either
         for consumption here or from the node daemon.
         @rtype: tuple
         @return: (master_netdev, master_ip, master_name)
         """
         try:
           cfg = _GetConfig()
           master_netdev = cfg.GetMasterNetdev()
           master_ip = cfg.GetMasterIP()
           master_node = cfg.GetMasterNode()
         except errors.ConfigurationError, err:
           logging.exception("Cluster configuration incomplete")
           return (None, None)
         return (master_netdev, master_ip, master_node)
       def StartMaster(start_daemons):
         """Activate local node as master node.
         The function will always try activate the IP address of the master
         (if someone else has it, then it won't). Then, if the start_daemons
         parameter is True, it will also start the master daemons
         (ganet-masterd and ganeti-rapi).
         """
         ok = True
         master_netdev, master_ip, _ = GetMasterInfo()
         if not master_netdev:
           return False
         if utils.TcpPing(master_ip, constants.DEFAULT_NODED_PORT):
           if utils.TcpPing(master_ip, constants.DEFAULT_NODED_PORT,
                            source=constants.LOCALHOST_IP_ADDRESS):
             # we already have the ip:
             logging.debug("Already started")
           else:
             logging.error("Someone else has the master ip, not activating")
             ok = False
         else:
           result = utils.RunCmd(["ip", "address", "add", "%s/32" % master_ip,
                                  "dev", master_netdev, "label",
                                  "%s:0" % master_netdev])
           if result.failed:
             logging.error("Can't activate master IP: %s", result.output)
             ok = False
           result = utils.RunCmd(["arping", "-q", "-U", "-c 3", "-I", master_netdev,
                                  "-s", master_ip, master_ip])
           # we'll ignore the exit code of arping
         # and now start the master and rapi daemons
         if start_daemons:
           for daemon in 'ganeti-masterd', 'ganeti-rapi':
             result = utils.RunCmd([daemon])
             if result.failed:
               logging.error("Can't start daemon %s: %s", daemon, result.output)
               ok = False
         return ok
       def StopMaster(stop_daemons):
         """Deactivate this node as master.
         The function will always try to deactivate the IP address of the
         master. Then, if the stop_daemons parameter is True, it will also
         stop the master daemons (ganet-masterd and ganeti-rapi).
         """
         master_netdev, master_ip, _ = GetMasterInfo()
         if not master_netdev:
           return False
         result = utils.RunCmd(["ip", "address", "del", "%s/32" % master_ip,
                                "dev", master_netdev])
         if result.failed:
           logging.error("Can't remove the master IP, error: %s", result.output)
           # but otherwise ignore the failure
         if stop_daemons:
           # stop/kill the rapi and the master daemon
           for daemon in constants.RAPI_PID, constants.MASTERD_PID:
             utils.KillProcess(utils.ReadPidFile(utils.DaemonPidFileName(daemon)))
         return True
       def AddNode(dsa, dsapub, rsa, rsapub, sshkey, sshpub):
         """Joins this node to the cluster.
         This does the following:
             - updates the hostkeys of the machine (rsa and dsa)
             - adds the ssh private key to the user
             - adds the ssh public key to the users' authorized_keys file
         """
         sshd_keys =  [(constants.SSH_HOST_RSA_PRIV, rsa, 0600),
                       (constants.SSH_HOST_RSA_PUB, rsapub, 0644),
                       (constants.SSH_HOST_DSA_PRIV, dsa, 0600),
                       (constants.SSH_HOST_DSA_PUB, dsapub, 0644)]
         for name, content, mode in sshd_keys:
           utils.WriteFile(name, data=content, mode=mode)
         try:
           priv_key, pub_key, auth_keys = ssh.GetUserFiles(constants.GANETI_RUNAS,
                                                           mkdir=True)
         except errors.OpExecError, err:
           logging.exception("Error while processing user ssh files")
           return False
         for name, content in [(priv_key, sshkey), (pub_key, sshpub)]:
           utils.WriteFile(name, data=content, mode=0600)
         utils.AddAuthorizedKey(auth_keys, sshpub)
         utils.RunCmd([constants.SSH_INITD_SCRIPT, "restart"])
         return True
       def LeaveCluster():
         """Cleans up the current node and prepares it to be removed from the cluster.
         """
         _CleanDirectory(constants.DATA_DIR)
         JobQueuePurge()
         try:
           priv_key, pub_key, auth_keys = ssh.GetUserFiles(constants.GANETI_RUNAS)
         except errors.OpExecError:
           logging.exception("Error while processing ssh files")
           return
         f = open(pub_key, 'r')
         try:
           utils.RemoveAuthorizedKey(auth_keys, f.read(8192))
         finally:
           f.close()
         utils.RemoveFile(priv_key)
         utils.RemoveFile(pub_key)
         # Return a reassuring string to the caller, and quit
         raise errors.QuitGanetiException(False, 'Shutdown scheduled')
       def GetNodeInfo(vgname):
         """Gives back a hash with different informations about the node.
         Returns:
           { 'vg_size' : xxx,  'vg_free' : xxx, 'memory_domain0': xxx,
             'memory_free' : xxx, 'memory_total' : xxx }
           where
           vg_size is the size of the configured volume group in MiB
           vg_free is the free size of the volume group in MiB
           memory_dom0 is the memory allocated for domain0 in MiB
           memory_free is the currently available (free) ram in MiB
           memory_total is the total number of ram in MiB
         """
         outputarray = {}
         vginfo = _GetVGInfo(vgname)
         outputarray['vg_size'] = vginfo['vg_size']
         outputarray['vg_free'] = vginfo['vg_free']
         hyper = hypervisor.GetHypervisor(_GetConfig())
         hyp_info = hyper.GetNodeInfo()
         if hyp_info is not None:
           outputarray.update(hyp_info)
         f = open("/proc/sys/kernel/random/boot_id", 'r')
         try:
           outputarray["bootid"] = f.read(128).rstrip("\n")
         finally:
           f.close()
         return outputarray
       def VerifyNode(what):
         """Verify the status of the local node.
         Args:
           what - a dictionary of things to check:
             'filelist' : list of files for which to compute checksums
             'nodelist' : list of nodes we should check communication with
             'hypervisor': run the hypervisor-specific verify
         Requested files on local node are checksummed and the result returned.
         The nodelist is traversed, with the following checks being made
         for each node:
         - known_hosts key correct
         - correct resolving of node name (target node returns its own hostname
           by ssh-execution of 'hostname', result compared against name in list.
         """
         result = {}
         if 'hypervisor' in what:
           result['hypervisor'] = hypervisor.GetHypervisor(_GetConfig()).Verify()
         if 'filelist' in what:
           result['filelist'] = utils.FingerprintFiles(what['filelist'])
         if 'nodelist' in what:
           result['nodelist'] = {}
           random.shuffle(what['nodelist'])
           for node in what['nodelist']:
             success, message = _GetSshRunner().VerifyNodeHostname(node)
             if not success:
               result['nodelist'][node] = message
         if 'node-net-test' in what:
           result['node-net-test'] = {}
           my_name = utils.HostInfo().name
           my_pip = my_sip = None
           for name, pip, sip in what['node-net-test']:
             if name == my_name:
               my_pip = pip
               my_sip = sip
               break
           if not my_pip:
             result['node-net-test'][my_name] = ("Can't find my own"
                                                 " primary/secondary IP"
                                                 " in the node list")
           else:
             port = utils.GetNodeDaemonPort()
             for name, pip, sip in what['node-net-test']:
               fail = []
               if not utils.TcpPing(pip, port, source=my_pip):
                 fail.append("primary")
               if sip != pip:
                 if not utils.TcpPing(sip, port, source=my_sip):
                   fail.append("secondary")
               if fail:
                 result['node-net-test'][name] = ("failure using the %s"
                                                  " interface(s)" %
                                                  " and ".join(fail))
         return result
       def GetVolumeList(vg_name):
         """Compute list of logical volumes and their size.
         Returns:
           dictionary of all partions (key) with their size (in MiB), inactive
           and online status:
           {'test1': ('20.06', True, True)}
         """
         lvs = {}
         sep = '|'
         result = utils.RunCmd(["lvs", "--noheadings", "--units=m", "--nosuffix",
                                "--separator=%s" % sep,
                                "-olv_name,lv_size,lv_attr", vg_name])
         if result.failed:
           logging.error("Failed to list logical volumes, lvs output: %s",
                         result.output)
           return result.output
         valid_line_re = re.compile("^ *([^|]+)\|([0-9.]+)\|([^|]{6})\|?$")
         for line in result.stdout.splitlines():
           line = line.strip()
           match = valid_line_re.match(line)
           if not match:
             logging.error("Invalid line returned from lvs output: '%s'", line)
             continue
           name, size, attr = match.groups()
           inactive = attr[4] == '-'
           online = attr[5] == 'o'
           lvs[name] = (size, inactive, online)
         return lvs
       def ListVolumeGroups():
         """List the volume groups and their size.
         Returns:
           Dictionary with keys volume name and values the size of the volume
         """
         return utils.ListVolumeGroups()
       def NodeVolumes():
         """List all volumes on this node.
         """
         result = utils.RunCmd(["lvs", "--noheadings", "--units=m", "--nosuffix",
                                "--separator=|",
                                "--options=lv_name,lv_size,devices,vg_name"])
         if result.failed:
           logging.error("Failed to list logical volumes, lvs output: %s",
                         result.output)
           return {}
         def parse_dev(dev):
           if '(' in dev:
             return dev.split('(')[0]
           else:
             return dev
         def map_line(line):
           return {
             'name': line[0].strip(),
             'size': line[1].strip(),
             'dev': parse_dev(line[2].strip()),
             'vg': line[3].strip(),
+          }
         return [map_line(line.split('|')) for line in result.stdout.splitlines()
                 if line.count('|') >= 3]
       def BridgesExist(bridges_list):
         """Check if a list of bridges exist on the current node.
         Returns:
           True if all of them exist, false otherwise
         """
         for bridge in bridges_list:
           if not utils.BridgeExists(bridge):
             return False
         return True
       def GetInstanceList():
         """Provides a list of instances.
         Returns:
           A list of all running instances on the current node
           - instance1.example.com
           - instance2.example.com
         """
         try:
           names = hypervisor.GetHypervisor(_GetConfig()).ListInstances()
         except errors.HypervisorError, err:
           logging.exception("Error enumerating instances")
           raise
         return names
       def GetInstanceInfo(instance):
         """Gives back the informations about an instance as a dictionary.
         Args:
           instance: name of the instance (ex. instance1.example.com)
         Returns:
           { 'memory' : 511, 'state' : '-b---', 'time' : 3188.8, }
           where
           memory: memory size of instance (int)
           state: xen state of instance (string)
           time: cpu time of instance (float)
         """
         output = {}
         iinfo = hypervisor.GetHypervisor(_GetConfig()).GetInstanceInfo(instance)
         if iinfo is not None:
           output['memory'] = iinfo[2]
           output['state'] = iinfo[4]
           output['time'] = iinfo[5]
         return output
       def GetAllInstancesInfo():
         """Gather data about all instances.
         This is the equivalent of `GetInstanceInfo()`, except that it
         computes data for all instances at once, thus being faster if one
         needs data about more than one instance.
         Returns: a dictionary of dictionaries, keys being the instance name,
           and with values:
           { 'memory' : 511, 'state' : '-b---', 'time' : 3188.8, }
           where
           memory: memory size of instance (int)
           state: xen state of instance (string)
           time: cpu time of instance (float)
           vcpus: the number of cpus
         """
         output = {}
         iinfo = hypervisor.GetHypervisor(_GetConfig()).GetAllInstancesInfo()
         if iinfo:
           for name, inst_id, memory, vcpus, state, times in iinfo:
             output[name] = {
               'memory': memory,
               'vcpus': vcpus,
               'state': state,
               'time': times,
+              }
         return output
       def AddOSToInstance(instance, os_disk, swap_disk):
         """Add an OS to an instance.
         Args:
           instance: the instance object
           os_disk: the instance-visible name of the os device
           swap_disk: the instance-visible name of the swap device
         """
         cfg = _GetConfig()
         inst_os = OSFromDisk(instance.os)
         create_script = inst_os.create_script
         os_device = instance.FindDisk(os_disk)
         if os_device is None:
           logging.error("Can't find this device-visible name '%s'", os_disk)
           return False
         swap_device = instance.FindDisk(swap_disk)
         if swap_device is None:
           logging.error("Can't find this device-visible name '%s'", swap_disk)
           return False
         real_os_dev = _RecursiveFindBD(os_device)
         if real_os_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(os_device))
         real_os_dev.Open()
         real_swap_dev = _RecursiveFindBD(swap_device)
         if real_swap_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(swap_device))
         real_swap_dev.Open()
         logfile = "%s/add-%s-%s-%d.log" % (constants.LOG_OS_DIR, instance.os,
                                            instance.name, int(time.time()))
         if not os.path.exists(constants.LOG_OS_DIR):
           os.mkdir(constants.LOG_OS_DIR, 0750)
         command = utils.BuildShellCmd("cd %s && %s -i %s -b %s -s %s &>%s",
                                       inst_os.path, create_script, instance.name,
                                       real_os_dev.dev_path, real_swap_dev.dev_path,
                                       logfile)
         env = {'HYPERVISOR': cfg.GetHypervisorType()}
         result = utils.RunCmd(command, env=env)
         if result.failed:
           logging.error("os create command '%s' returned error: %s, logfile: %s,"
                         " output: %s", command, result.fail_reason, logfile,
                         result.output)
           return False
         return True
       def RunRenameInstance(instance, old_name, os_disk, swap_disk):
         """Run the OS rename script for an instance.
         Args:
           instance: the instance object
           old_name: the old name of the instance
           os_disk: the instance-visible name of the os device
           swap_disk: the instance-visible name of the swap device
         """
         inst_os = OSFromDisk(instance.os)
         script = inst_os.rename_script
         os_device = instance.FindDisk(os_disk)
         if os_device is None:
           logging.error("Can't find this device-visible name '%s'", os_disk)
           return False
         swap_device = instance.FindDisk(swap_disk)
         if swap_device is None:
           logging.error("Can't find this device-visible name '%s'", swap_disk)
           return False
         real_os_dev = _RecursiveFindBD(os_device)
         if real_os_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(os_device))
         real_os_dev.Open()
         real_swap_dev = _RecursiveFindBD(swap_device)
         if real_swap_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(swap_device))
         real_swap_dev.Open()
         logfile = "%s/rename-%s-%s-%s-%d.log" % (constants.LOG_OS_DIR, instance.os,
                                                  old_name,
                                                  instance.name, int(time.time()))
         if not os.path.exists(constants.LOG_OS_DIR):
           os.mkdir(constants.LOG_OS_DIR, 0750)
         command = utils.BuildShellCmd("cd %s && %s -o %s -n %s -b %s -s %s &>%s",
                                       inst_os.path, script, old_name, instance.name,
                                       real_os_dev.dev_path, real_swap_dev.dev_path,
                                       logfile)
         result = utils.RunCmd(command)
         if result.failed:
           logging.error("os create command '%s' returned error: %s output: %s",
                         command, result.fail_reason, result.output)
           return False
         return True
       def _GetVGInfo(vg_name):
         """Get informations about the volume group.
         Args:
           vg_name: the volume group
         Returns:
           { 'vg_size' : xxx, 'vg_free' : xxx, 'pv_count' : xxx }
           where
           vg_size is the total size of the volume group in MiB
           vg_free is the free size of the volume group in MiB
           pv_count are the number of physical disks in that vg
         If an error occurs during gathering of data, we return the same dict
         with keys all set to None.
         """
         retdic = dict.fromkeys(["vg_size", "vg_free", "pv_count"])
         retval = utils.RunCmd(["vgs", "-ovg_size,vg_free,pv_count", "--noheadings",
                                "--nosuffix", "--units=m", "--separator=:", vg_name])
         if retval.failed:
           logging.error("volume group %s not present", vg_name)
           return retdic
         valarr = retval.stdout.strip().rstrip(':').split(':')
         if len(valarr) == 3:
           try:
             retdic = {
               "vg_size": int(round(float(valarr[0]), 0)),
               "vg_free": int(round(float(valarr[1]), 0)),
               "pv_count": int(valarr[2]),
+              }
           except ValueError, err:
             logging.exception("Fail to parse vgs output")
         else:
           logging.error("vgs output has the wrong number of fields (expected"
                         " three): %s", str(valarr))
         return retdic
       def _GatherBlockDevs(instance):
         """Set up an instance's block device(s).
         This is run on the primary node at instance startup. The block
         devices must be already assembled.
         """
         block_devices = []
         for disk in instance.disks:
           device = _RecursiveFindBD(disk)
           if device is None:
             raise errors.BlockDeviceError("Block device '%s' is not set up." %
                                           str(disk))
           device.Open()
           block_devices.append((disk, device))
         return block_devices
       def StartInstance(instance, extra_args):
         """Start an instance.
         Args:
           instance - name of instance to start.
         """
         running_instances = GetInstanceList()
         if instance.name in running_instances:
           return True
         block_devices = _GatherBlockDevs(instance)
         hyper = hypervisor.GetHypervisor(_GetConfig())
         try:
           hyper.StartInstance(instance, block_devices, extra_args)
         except errors.HypervisorError, err:
           logging.exception("Failed to start instance")
           return False
         return True
       def ShutdownInstance(instance):
         """Shut an instance down.
         Args:
           instance - name of instance to shutdown.
         """
         running_instances = GetInstanceList()
         if instance.name not in running_instances:
           return True
         hyper = hypervisor.GetHypervisor(_GetConfig())
         try:
           hyper.StopInstance(instance)
         except errors.HypervisorError, err:
           logging.error("Failed to stop instance")
           return False
         # test every 10secs for 2min
         shutdown_ok = False
         time.sleep(1)
         for dummy in range(11):
           if instance.name not in GetInstanceList():
             break
           time.sleep(10)
         else:
           # the shutdown did not succeed
           logging.error("shutdown of '%s' unsuccessful, using destroy", instance)
           try:
             hyper.StopInstance(instance, force=True)
           except errors.HypervisorError, err:
             logging.exception("Failed to stop instance")
             return False
           time.sleep(1)
           if instance.name in GetInstanceList():
             logging.error("could not shutdown instance '%s' even by destroy",
                           instance.name)
             return False
         return True
       def RebootInstance(instance, reboot_type, extra_args):
         """Reboot an instance.
         Args:
           instance    - name of instance to reboot
           reboot_type - how to reboot [soft,hard,full]
         """
         running_instances = GetInstanceList()
         if instance.name not in running_instances:
           logging.error("Cannot reboot instance that is not running")
           return False
         hyper = hypervisor.GetHypervisor(_GetConfig())
         if reboot_type == constants.INSTANCE_REBOOT_SOFT:
           try:
             hyper.RebootInstance(instance)
           except errors.HypervisorError, err:
             logging.exception("Failed to soft reboot instance")
             return False
         elif reboot_type == constants.INSTANCE_REBOOT_HARD:
           try:
             ShutdownInstance(instance)
             StartInstance(instance, extra_args)
           except errors.HypervisorError, err:
             logging.exception("Failed to hard reboot instance")
             return False
         else:
           raise errors.ParameterError("reboot_type invalid")
         return True
       def MigrateInstance(instance, target, live):
         """Migrates an instance to another node.
         """
         hyper = hypervisor.GetHypervisor(_GetConfig())
         try:
           hyper.MigrateInstance(instance, target, live)
         except errors.HypervisorError, err:
           msg = "Failed to migrate instance: %s" % str(err)
           logging.error(msg)
           return (False, msg)
         return (True, "Migration successfull")
       def CreateBlockDevice(disk, size, owner, on_primary, info):
         """Creates a block device for an instance.
         Args:
          disk: a ganeti.objects.Disk object
          size: the size of the physical underlying device
          owner: a string with the name of the instance
          on_primary: a boolean indicating if it is the primary node or not
          info: string that will be sent to the physical device creation
         Returns:
           the new unique_id of the device (this can sometime be
           computed only after creation), or None. On secondary nodes,
           it's not required to return anything.
         """
         clist = []
         if disk.children:
           for child in disk.children:
             crdev = _RecursiveAssembleBD(child, owner, on_primary)
             if on_primary or disk.AssembleOnSecondary():
               # we need the children open in case the device itself has to
               # be assembled
               crdev.Open()
             clist.append(crdev)
         try:
           device = bdev.FindDevice(disk.dev_type, disk.physical_id, clist)
           if device is not None:
             logging.info("removing existing device %s", disk)
             device.Remove()
         except errors.BlockDeviceError, err:
           pass
         device = bdev.Create(disk.dev_type, disk.physical_id,
                              clist, size)
         if device is None:
           raise ValueError("Can't create child device for %s, %s" %
                            (disk, size))
         if on_primary or disk.AssembleOnSecondary():
           if not device.Assemble():
             errorstring = "Can't assemble device after creation"
             logging.error(errorstring)
             raise errors.BlockDeviceError("%s, very unusual event - check the node"
                                           " daemon logs" % errorstring)
           device.SetSyncSpeed(constants.SYNC_SPEED)
           if on_primary or disk.OpenOnSecondary():
             device.Open(force=True)
           DevCacheManager.UpdateCache(device.dev_path, owner,
                                       on_primary, disk.iv_name)
         device.SetInfo(info)
         physical_id = device.unique_id
         return physical_id
       def RemoveBlockDevice(disk):
         """Remove a block device.
         This is intended to be called recursively.
         """
         try:
           # since we are removing the device, allow a partial match
           # this allows removal of broken mirrors
           rdev = _RecursiveFindBD(disk, allow_partial=True)
         except errors.BlockDeviceError, err:
           # probably can't attach
           logging.info("Can't attach to device %s in remove", disk)
           rdev = None
         if rdev is not None:
           r_path = rdev.dev_path
           result = rdev.Remove()
           if result:
             DevCacheManager.RemoveCache(r_path)
         else:
           result = True
         if disk.children:
           for child in disk.children:
             result = result and RemoveBlockDevice(child)
         return result
       def _RecursiveAssembleBD(disk, owner, as_primary):
         """Activate a block device for an instance.
         This is run on the primary and secondary nodes for an instance.
         This function is called recursively.
         Args:
           disk: a objects.Disk object
           as_primary: if we should make the block device read/write
         Returns:
           the assembled device or None (in case no device was assembled)
         If the assembly is not successful, an exception is raised.
         """
         children = []
         if disk.children:
           mcn = disk.ChildrenNeeded()
           if mcn == -1:
             mcn = 0 # max number of Nones allowed
           else:
             mcn = len(disk.children) - mcn # max number of Nones
           for chld_disk in disk.children:
             try:
               cdev = _RecursiveAssembleBD(chld_disk, owner, as_primary)
             except errors.BlockDeviceError, err:
               if children.count(None) >= mcn:
                 raise
               cdev = None
               logging.debug("Error in child activation: %s", str(err))
             children.append(cdev)
         if as_primary or disk.AssembleOnSecondary():
           r_dev = bdev.AttachOrAssemble(disk.dev_type, disk.physical_id, children)
           r_dev.SetSyncSpeed(constants.SYNC_SPEED)
           result = r_dev
           if as_primary or disk.OpenOnSecondary():
             r_dev.Open()
           DevCacheManager.UpdateCache(r_dev.dev_path, owner,
                                       as_primary, disk.iv_name)
         else:
           result = True
         return result
       def AssembleBlockDevice(disk, owner, as_primary):
         """Activate a block device for an instance.
         This is a wrapper over _RecursiveAssembleBD.
         Returns:
           a /dev path for primary nodes
           True for secondary nodes
         """
         result = _RecursiveAssembleBD(disk, owner, as_primary)
         if isinstance(result, bdev.BlockDev):
           result = result.dev_path
         return result
       def ShutdownBlockDevice(disk):
         """Shut down a block device.
         First, if the device is assembled (can `Attach()`), then the device
         is shutdown. Then the children of the device are shutdown.
         This function is called recursively. Note that we don't cache the
         children or such, as oppossed to assemble, shutdown of different
         devices doesn't require that the upper device was active.
         """
         r_dev = _RecursiveFindBD(disk)
         if r_dev is not None:
           r_path = r_dev.dev_path
           result = r_dev.Shutdown()
           if result:
             DevCacheManager.RemoveCache(r_path)
         else:
           result = True
         if disk.children:
           for child in disk.children:
             result = result and ShutdownBlockDevice(child)
         return result
       def MirrorAddChildren(parent_cdev, new_cdevs):
         """Extend a mirrored block device.
         """
         parent_bdev = _RecursiveFindBD(parent_cdev, allow_partial=True)
         if parent_bdev is None:
           logging.error("Can't find parent device")
           return False
         new_bdevs = [_RecursiveFindBD(disk) for disk in new_cdevs]
         if new_bdevs.count(None) > 0:
           logging.error("Can't find new device(s) to add: %s:%s",
                         new_bdevs, new_cdevs)
           return False
         parent_bdev.AddChildren(new_bdevs)
         return True
       def MirrorRemoveChildren(parent_cdev, new_cdevs):
         """Shrink a mirrored block device.
         """
         parent_bdev = _RecursiveFindBD(parent_cdev)
         if parent_bdev is None:
           logging.error("Can't find parent in remove children: %s", parent_cdev)
           return False
         devs = []
         for disk in new_cdevs:
           rpath = disk.StaticDevPath()
           if rpath is None:
             bd = _RecursiveFindBD(disk)
             if bd is None:
               logging.error("Can't find dynamic device %s while removing children",
                             disk)
               return False
             else:
               devs.append(bd.dev_path)
           else:
             devs.append(rpath)
         parent_bdev.RemoveChildren(devs)
         return True
       def GetMirrorStatus(disks):
         """Get the mirroring status of a list of devices.
         Args:
           disks: list of `objects.Disk`
         Returns:
           list of (mirror_done, estimated_time) tuples, which
           are the result of bdev.BlockDevice.CombinedSyncStatus()
         """
         stats = []
         for dsk in disks:
           rbd = _RecursiveFindBD(dsk)
           if rbd is None:
             raise errors.BlockDeviceError("Can't find device %s" % str(dsk))
           stats.append(rbd.CombinedSyncStatus())
         return stats
       def _RecursiveFindBD(disk, allow_partial=False):
         """Check if a device is activated.
         If so, return informations about the real device.
         Args:
           disk: the objects.Disk instance
           allow_partial: don't abort the find if a child of the
                          device can't be found; this is intended to be
                          used when repairing mirrors
         Returns:
           None if the device can't be found
           otherwise the device instance
         """
         children = []
         if disk.children:
           for chdisk in disk.children:
             children.append(_RecursiveFindBD(chdisk))
         return bdev.FindDevice(disk.dev_type, disk.physical_id, children)
       def FindBlockDevice(disk):
         """Check if a device is activated.
         If so, return informations about the real device.
         Args:
           disk: the objects.Disk instance
         Returns:
           None if the device can't be found
           (device_path, major, minor, sync_percent, estimated_time, is_degraded)
         """
         rbd = _RecursiveFindBD(disk)
         if rbd is None:
           return rbd
         return (rbd.dev_path, rbd.major, rbd.minor) + rbd.GetSyncStatus()
       def UploadFile(file_name, data, mode, uid, gid, atime, mtime):
         """Write a file to the filesystem.
         This allows the master to overwrite(!) a file. It will only perform
         the operation if the file belongs to a list of configuration files.
         """
         if not os.path.isabs(file_name):
           logging.error("Filename passed to UploadFile is not absolute: '%s'",
                         file_name)
           return False
         allowed_files = [
           constants.CLUSTER_CONF_FILE,
           constants.ETC_HOSTS,
           constants.SSH_KNOWN_HOSTS_FILE,
           constants.VNC_PASSWORD_FILE,
+          ]
         if file_name not in allowed_files:
           logging.error("Filename passed to UploadFile not in allowed"
                        " upload targets: '%s'", file_name)
           return False
         utils.WriteFile(file_name, data=data, mode=mode, uid=uid, gid=gid,
                         atime=atime, mtime=mtime)
         return True
       def _ErrnoOrStr(err):
         """Format an EnvironmentError exception.
         If the `err` argument has an errno attribute, it will be looked up
         and converted into a textual EXXXX description. Otherwise the string
         representation of the error will be returned.
         """
         if hasattr(err, 'errno'):
           detail = errno.errorcode[err.errno]
         else:
           detail = str(err)
         return detail
       def _OSOndiskVersion(name, os_dir):
         """Compute and return the API version of a given OS.
         This function will try to read the API version of the os given by
         the 'name' parameter and residing in the 'os_dir' directory.
         Return value will be either an integer denoting the version or None in the
         case when this is not a valid OS name.
         """
         api_file = os.path.sep.join([os_dir, "ganeti_api_version"])
         try:
           st = os.stat(api_file)
         except EnvironmentError, err:
           raise errors.InvalidOS(name, os_dir, "'ganeti_api_version' file not"
                                  " found (%s)" % _ErrnoOrStr(err))
         if not stat.S_ISREG(stat.S_IFMT(st.st_mode)):
           raise errors.InvalidOS(name, os_dir, "'ganeti_api_version' file is not"
                                  " a regular file")
         try:
           f = open(api_file)
           try:
             api_version = f.read(256)
           finally:
             f.close()
         except EnvironmentError, err:
           raise errors.InvalidOS(name, os_dir, "error while reading the"
                                  " API version (%s)" % _ErrnoOrStr(err))
         api_version = api_version.strip()
         try:
           api_version = int(api_version)
         except (TypeError, ValueError), err:
           raise errors.InvalidOS(name, os_dir,
                                  "API version is not integer (%s)" % str(err))
         return api_version
       def DiagnoseOS(top_dirs=None):
         """Compute the validity for all OSes.
         Returns an OS object for each name in all the given top directories
         (if not given defaults to constants.OS_SEARCH_PATH)
         Returns:
           list of OS objects
         """
         if top_dirs is None:
           top_dirs = constants.OS_SEARCH_PATH
         result = []
         for dir_name in top_dirs:
           if os.path.isdir(dir_name):
             try:
               f_names = utils.ListVisibleFiles(dir_name)
             except EnvironmentError, err:
               logging.exception("Can't list the OS directory %s", dir_name)
               break
             for name in f_names:
               try:
                 os_inst = OSFromDisk(name, base_dir=dir_name)
                 result.append(os_inst)
               except errors.InvalidOS, err:
                 result.append(objects.OS.FromInvalidOS(err))
         return result
       def OSFromDisk(name, base_dir=None):
         """Create an OS instance from disk.
         This function will return an OS instance if the given name is a
         valid OS name. Otherwise, it will raise an appropriate
         `errors.InvalidOS` exception, detailing why this is not a valid
         OS.
         Args:
           os_dir: Directory containing the OS scripts. Defaults to a search
                   in all the OS_SEARCH_PATH directories.
         """
         if base_dir is None:
           os_dir = utils.FindFile(name, constants.OS_SEARCH_PATH, os.path.isdir)
           if os_dir is None:
             raise errors.InvalidOS(name, None, "OS dir not found in search path")
         else:
           os_dir = os.path.sep.join([base_dir, name])
         api_version = _OSOndiskVersion(name, os_dir)
         if api_version != constants.OS_API_VERSION:
           raise errors.InvalidOS(name, os_dir, "API version mismatch"
                                  " (found %s want %s)"
                                  % (api_version, constants.OS_API_VERSION))
         # OS Scripts dictionary, we will populate it with the actual script names
         os_scripts = {'create': '', 'export': '', 'import': '', 'rename': ''}
         for script in os_scripts:
           os_scripts[script] = os.path.sep.join([os_dir, script])
           try:
             st = os.stat(os_scripts[script])
           except EnvironmentError, err:
             raise errors.InvalidOS(name, os_dir, "'%s' script missing (%s)" %
                                    (script, _ErrnoOrStr(err)))
           if stat.S_IMODE(st.st_mode) & stat.S_IXUSR != stat.S_IXUSR:
             raise errors.InvalidOS(name, os_dir, "'%s' script not executable" %
                                    script)
           if not stat.S_ISREG(stat.S_IFMT(st.st_mode)):
             raise errors.InvalidOS(name, os_dir, "'%s' is not a regular file" %
                                    script)
         return objects.OS(name=name, path=os_dir, status=constants.OS_VALID_STATUS,
                           create_script=os_scripts['create'],
                           export_script=os_scripts['export'],
                           import_script=os_scripts['import'],
                           rename_script=os_scripts['rename'],
                           api_version=api_version)
       def GrowBlockDevice(disk, amount):
         """Grow a stack of block devices.
         This function is called recursively, with the childrens being the
         first one resize.
         Args:
           disk: the disk to be grown
         Returns: a tuple of (status, result), with:
           status: the result (true/false) of the operation
           result: the error message if the operation failed, otherwise not used
         """
         r_dev = _RecursiveFindBD(disk)
         if r_dev is None:
           return False, "Cannot find block device %s" % (disk,)
         try:
           r_dev.Grow(amount)
         except errors.BlockDeviceError, err:
           return False, str(err)
         return True, None
       def SnapshotBlockDevice(disk):
         """Create a snapshot copy of a block device.
         This function is called recursively, and the snapshot is actually created
         just for the leaf lvm backend device.
         Args:
           disk: the disk to be snapshotted
         Returns:
           a config entry for the actual lvm device snapshotted.
         """
         if disk.children:
           if len(disk.children) == 1:
             # only one child, let's recurse on it
             return SnapshotBlockDevice(disk.children[0])
           else:
             # more than one child, choose one that matches
             for child in disk.children:
               if child.size == disk.size:
                 # return implies breaking the loop
                 return SnapshotBlockDevice(child)
         elif disk.dev_type == constants.LD_LV:
           r_dev = _RecursiveFindBD(disk)
           if r_dev is not None:
             # let's stay on the safe side and ask for the full size, for now
             return r_dev.Snapshot(disk.size)
           else:
             return None
         else:
           raise errors.ProgrammerError("Cannot snapshot non-lvm block device"
                                        " '%s' of type '%s'" %
                                        (disk.unique_id, disk.dev_type))
       def ExportSnapshot(disk, dest_node, instance):
         """Export a block device snapshot to a remote node.
         Args:
           disk: the snapshot block device
           dest_node: the node to send the image to
           instance: instance being exported
         Returns:
           True if successful, False otherwise.
         """
         inst_os = OSFromDisk(instance.os)
         export_script = inst_os.export_script
         logfile = "%s/exp-%s-%s-%s.log" % (constants.LOG_OS_DIR, inst_os.name,
                                            instance.name, int(time.time()))
         if not os.path.exists(constants.LOG_OS_DIR):
           os.mkdir(constants.LOG_OS_DIR, 0750)
         real_os_dev = _RecursiveFindBD(disk)
         if real_os_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(disk))
         real_os_dev.Open()
         destdir = os.path.join(constants.EXPORT_DIR, instance.name + ".new")
         destfile = disk.physical_id[1]
         # the target command is built out of three individual commands,
         # which are joined by pipes; we check each individual command for
         # valid parameters
         expcmd = utils.BuildShellCmd("cd %s; %s -i %s -b %s 2>%s", inst_os.path,
                                      export_script, instance.name,
                                      real_os_dev.dev_path, logfile)
         comprcmd = "gzip"
         destcmd = utils.BuildShellCmd("mkdir -p %s && cat > %s/%s",
                                       destdir, destdir, destfile)
         remotecmd = _GetSshRunner().BuildCmd(dest_node, constants.GANETI_RUNAS,
                                              destcmd)
         # all commands have been checked, so we're safe to combine them
         command = '|'.join([expcmd, comprcmd, utils.ShellQuoteArgs(remotecmd)])
         result = utils.RunCmd(command)
         if result.failed:
           logging.error("os snapshot export command '%s' returned error: %s"
                         " output: %s", command, result.fail_reason, result.output)
           return False
         return True
       def FinalizeExport(instance, snap_disks):
         """Write out the export configuration information.
         Args:
           instance: instance configuration
           snap_disks: snapshot block devices
         Returns:
           False in case of error, True otherwise.
         """
         destdir = os.path.join(constants.EXPORT_DIR, instance.name + ".new")
         finaldestdir = os.path.join(constants.EXPORT_DIR, instance.name)
         config = objects.SerializableConfigParser()
         config.add_section(constants.INISECT_EXP)
         config.set(constants.INISECT_EXP, 'version', '0')
         config.set(constants.INISECT_EXP, 'timestamp', '%d' % int(time.time()))
         config.set(constants.INISECT_EXP, 'source', instance.primary_node)
         config.set(constants.INISECT_EXP, 'os', instance.os)
         config.set(constants.INISECT_EXP, 'compression', 'gzip')
         config.add_section(constants.INISECT_INS)
         config.set(constants.INISECT_INS, 'name', instance.name)
         config.set(constants.INISECT_INS, 'memory', '%d' % instance.memory)
         config.set(constants.INISECT_INS, 'vcpus', '%d' % instance.vcpus)
         config.set(constants.INISECT_INS, 'disk_template', instance.disk_template)
         nic_count = 0
         for nic_count, nic in enumerate(instance.nics):
           config.set(constants.INISECT_INS, 'nic%d_mac' %
                      nic_count, '%s' % nic.mac)
           config.set(constants.INISECT_INS, 'nic%d_ip' % nic_count, '%s' % nic.ip)
           config.set(constants.INISECT_INS, 'nic%d_bridge' % nic_count,
                      '%s' % nic.bridge)
         # TODO: redundant: on load can read nics until it doesn't exist
         config.set(constants.INISECT_INS, 'nic_count' , '%d' % nic_count)
         disk_count = 0
         for disk_count, disk in enumerate(snap_disks):
           config.set(constants.INISECT_INS, 'disk%d_ivname' % disk_count,
                      ('%s' % disk.iv_name))
           config.set(constants.INISECT_INS, 'disk%d_dump' % disk_count,
                      ('%s' % disk.physical_id[1]))
           config.set(constants.INISECT_INS, 'disk%d_size' % disk_count,
                      ('%d' % disk.size))
         config.set(constants.INISECT_INS, 'disk_count' , '%d' % disk_count)
         cff = os.path.join(destdir, constants.EXPORT_CONF_FILE)
         cfo = open(cff, 'w')
         try:
           config.write(cfo)
         finally:
           cfo.close()
         shutil.rmtree(finaldestdir, True)
         shutil.move(destdir, finaldestdir)
         return True
       def ExportInfo(dest):
         """Get export configuration information.
         Args:
           dest: directory containing the export
         Returns:
           A serializable config file containing the export info.
         """
         cff = os.path.join(dest, constants.EXPORT_CONF_FILE)
         config = objects.SerializableConfigParser()
         config.read(cff)
         if (not config.has_section(constants.INISECT_EXP) or
             not config.has_section(constants.INISECT_INS)):
           return None
         return config
       def ImportOSIntoInstance(instance, os_disk, swap_disk, src_node, src_image):
         """Import an os image into an instance.
         Args:
           instance: the instance object
           os_disk: the instance-visible name of the os device
           swap_disk: the instance-visible name of the swap device
           src_node: node holding the source image
           src_image: path to the source image on src_node
         Returns:
           False in case of error, True otherwise.
         """
         cfg = _GetConfig()
         inst_os = OSFromDisk(instance.os)
         import_script = inst_os.import_script
         os_device = instance.FindDisk(os_disk)
         if os_device is None:
           logging.error("Can't find this device-visible name '%s'", os_disk)
           return False
         swap_device = instance.FindDisk(swap_disk)
         if swap_device is None:
           logging.error("Can't find this device-visible name '%s'", swap_disk)
           return False
         real_os_dev = _RecursiveFindBD(os_device)
         if real_os_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(os_device))
         real_os_dev.Open()
         real_swap_dev = _RecursiveFindBD(swap_device)
         if real_swap_dev is None:
           raise errors.BlockDeviceError("Block device '%s' is not set up" %
                                         str(swap_device))
         real_swap_dev.Open()
         logfile = "%s/import-%s-%s-%s.log" % (constants.LOG_OS_DIR, instance.os,
                                               instance.name, int(time.time()))
         if not os.path.exists(constants.LOG_OS_DIR):
           os.mkdir(constants.LOG_OS_DIR, 0750)
         destcmd = utils.BuildShellCmd('cat %s', src_image)
         remotecmd = _GetSshRunner().BuildCmd(src_node, constants.GANETI_RUNAS,
                                              destcmd)
         comprcmd = "gunzip"
         impcmd = utils.BuildShellCmd("(cd %s; %s -i %s -b %s -s %s &>%s)",
                                      inst_os.path, import_script, instance.name,
                                      real_os_dev.dev_path, real_swap_dev.dev_path,
                                      logfile)
         command = '|'.join([utils.ShellQuoteArgs(remotecmd), comprcmd, impcmd])
         env = {'HYPERVISOR': cfg.GetHypervisorType()}
         result = utils.RunCmd(command, env=env)
         if result.failed:
           logging.error("os import command '%s' returned error: %s"
                         " output: %s", command, result.fail_reason, result.output)
           return False
         return True
       def ListExports():
         """Return a list of exports currently available on this machine.
         """
         if os.path.isdir(constants.EXPORT_DIR):
           return utils.ListVisibleFiles(constants.EXPORT_DIR)
         else:
           return []
       def RemoveExport(export):
         """Remove an existing export from the node.
         Args:
           export: the name of the export to remove
         Returns:
           False in case of error, True otherwise.
         """
         target = os.path.join(constants.EXPORT_DIR, export)
         shutil.rmtree(target)
         # TODO: catch some of the relevant exceptions and provide a pretty
         # error message if rmtree fails.
         return True
       def RenameBlockDevices(devlist):
         """Rename a list of block devices.
         The devlist argument is a list of tuples (disk, new_logical,
         new_physical). The return value will be a combined boolean result
         (True only if all renames succeeded).
         """
         result = True
         for disk, unique_id in devlist:
           dev = _RecursiveFindBD(disk)
           if dev is None:
             result = False
             continue
           try:
             old_rpath = dev.dev_path
             dev.Rename(unique_id)
             new_rpath = dev.dev_path
             if old_rpath != new_rpath:
               DevCacheManager.RemoveCache(old_rpath)
               # FIXME: we should add the new cache information here, like:
               # DevCacheManager.UpdateCache(new_rpath, owner, ...)
               # but we don't have the owner here - maybe parse from existing
               # cache? for now, we only lose lvm data when we rename, which
               # is less critical than DRBD or MD
           except errors.BlockDeviceError, err:
             logging.exception("Can't rename device '%s' to '%s'", dev, unique_id)
             result = False
         return result
       def _TransformFileStorageDir(file_storage_dir):
         """Checks whether given file_storage_dir is valid.
         Checks wheter the given file_storage_dir is within the cluster-wide
         default file_storage_dir stored in SimpleStore. Only paths under that
         directory are allowed.
         Args:
           file_storage_dir: string with path
         Returns:
           normalized file_storage_dir (string) if valid, None otherwise
         """
         cfg = _GetConfig()
         file_storage_dir = os.path.normpath(file_storage_dir)
         base_file_storage_dir = cfg.GetFileStorageDir()
         if (not os.path.commonprefix([file_storage_dir, base_file_storage_dir]) ==
             base_file_storage_dir):
           logging.error("file storage directory '%s' is not under base file"
                         " storage directory '%s'",
                         file_storage_dir, base_file_storage_dir)
           return None
         return file_storage_dir
       def CreateFileStorageDir(file_storage_dir):
         """Create file storage directory.
         Args:
           file_storage_dir: string containing the path
         Returns:
           tuple with first element a boolean indicating wheter dir
           creation was successful or not
         """
         file_storage_dir = _TransformFileStorageDir(file_storage_dir)
         result = True,
         if not file_storage_dir:
           result = False,
         else:
           if os.path.exists(file_storage_dir):
             if not os.path.isdir(file_storage_dir):
               logging.error("'%s' is not a directory", file_storage_dir)
               result = False,
           else:
             try:
               os.makedirs(file_storage_dir, 0750)
             except OSError, err:
               logging.error("Cannot create file storage directory '%s': %s",
                             file_storage_dir, err)
               result = False,
         return result
       def RemoveFileStorageDir(file_storage_dir):
         """Remove file storage directory.
         Remove it only if it's empty. If not log an error and return.
         Args:
           file_storage_dir: string containing the path
         Returns:
           tuple with first element a boolean indicating wheter dir
           removal was successful or not
         """
         file_storage_dir = _TransformFileStorageDir(file_storage_dir)
         result = True,
         if not file_storage_dir:
           result = False,
         else:
           if os.path.exists(file_storage_dir):
             if not os.path.isdir(file_storage_dir):
               logging.error("'%s' is not a directory", file_storage_dir)
               result = False,
             # deletes dir only if empty, otherwise we want to return False
             try:
               os.rmdir(file_storage_dir)
             except OSError, err:
               logging.exception("Cannot remove file storage directory '%s'",
                                 file_storage_dir)
               result = False,
         return result
       def RenameFileStorageDir(old_file_storage_dir, new_file_storage_dir):
         """Rename the file storage directory.
         Args:
           old_file_storage_dir: string containing the old path
           new_file_storage_dir: string containing the new path
         Returns:
           tuple with first element a boolean indicating wheter dir
           rename was successful or not
         """
         old_file_storage_dir = _TransformFileStorageDir(old_file_storage_dir)
         new_file_storage_dir = _TransformFileStorageDir(new_file_storage_dir)
         result = True,
         if not old_file_storage_dir or not new_file_storage_dir:
           result = False,
         else:
           if not os.path.exists(new_file_storage_dir):
             if os.path.isdir(old_file_storage_dir):
               try:
                 os.rename(old_file_storage_dir, new_file_storage_dir)
               except OSError, err:
                 logging.exception("Cannot rename '%s' to '%s'",
                                   old_file_storage_dir, new_file_storage_dir)
                 result =  False,
             else:
               logging.error("'%s' is not a directory", old_file_storage_dir)
               result = False,
           else:
             if os.path.exists(old_file_storage_dir):
               logging.error("Cannot rename '%s' to '%s'. Both locations exist.",
                             old_file_storage_dir, new_file_storage_dir)
               result = False,
         return result
       def _IsJobQueueFile(file_name):
         """Checks whether the given filename is in the queue directory.
         """
         queue_dir = os.path.normpath(constants.QUEUE_DIR)
         result = (os.path.commonprefix([queue_dir, file_name]) == queue_dir)
         if not result:
           logging.error("'%s' is not a file in the queue directory",
                         file_name)
         return result
       def JobQueueUpdate(file_name, content):
         """Updates a file in the queue directory.
         """
         if not _IsJobQueueFile(file_name):
           return False
         # Write and replace the file atomically
         utils.WriteFile(file_name, data=content)
         return True
       def JobQueueRename(old, new):
         """Renames a job queue file.
         """
         if not (_IsJobQueueFile(old) and _IsJobQueueFile(new)):
           return False
         os.rename(old, new)
         return True
       def CloseBlockDevices(disks):
         """Closes the given block devices.
         This means they will be switched to secondary mode (in case of DRBD).
         """
         bdevs = []
         for cf in disks:
           rd = _RecursiveFindBD(cf)
           if rd is None:
             return (False, "Can't find device %s" % cf)
           bdevs.append(rd)
         msg = []
         for rd in bdevs:
           try:
             rd.Close()
           except errors.BlockDeviceError, err:
             msg.append(str(err))
         if msg:
           return (False, "Can't make devices secondary: %s" % ",".join(msg))
         else:
           return (True, "All devices secondary")
       class HooksRunner(object):
         """Hook runner.
         This class is instantiated on the node side (ganeti-noded) and not on
         the master side.
         """
         RE_MASK = re.compile("^[a-zA-Z0-9_-]+$")
         def __init__(self, hooks_base_dir=None):
           """Constructor for hooks runner.
           Args:
             - hooks_base_dir: if not None, this overrides the
               constants.HOOKS_BASE_DIR (useful for unittests)
           """
           if hooks_base_dir is None:
             hooks_base_dir = constants.HOOKS_BASE_DIR
           self._BASE_DIR = hooks_base_dir
         @staticmethod
         def ExecHook(script, env):
           """Exec one hook script.
           Args:
            - script: the full path to the script
            - env: the environment with which to exec the script
           """
           # exec the process using subprocess and log the output
           fdstdin = None
           try:
             fdstdin = open("/dev/null", "r")
             child = subprocess.Popen([script], stdin=fdstdin, stdout=subprocess.PIPE,
                                      stderr=subprocess.STDOUT, close_fds=True,
                                      shell=False, cwd="/", env=env)
             output = ""
             try:
               output = child.stdout.read(4096)
               child.stdout.close()
             except EnvironmentError, err:
               output += "Hook script error: %s" % str(err)
             while True:
               try:
                 result = child.wait()
                 break
               except EnvironmentError, err:
                 if err.errno == errno.EINTR:
                   continue
                 raise
           finally:
             # try not to leak fds
             for fd in (fdstdin, ):
               if fd is not None:
                 try:
                   fd.close()
                 except EnvironmentError, err:
                   # just log the error
                   #logging.exception("Error while closing fd %s", fd)
                   pass
           return result == 0, output
         def RunHooks(self, hpath, phase, env):
           """Run the scripts in the hooks directory.
           This method will not be usually overriden by child opcodes.
           """
           if phase == constants.HOOKS_PHASE_PRE:
             suffix = "pre"
           elif phase == constants.HOOKS_PHASE_POST:
             suffix = "post"
           else:
             raise errors.ProgrammerError("Unknown hooks phase: '%s'" % phase)
           rr = []
           subdir = "%s-%s.d" % (hpath, suffix)
           dir_name = "%s/%s" % (self._BASE_DIR, subdir)
           try:
             dir_contents = utils.ListVisibleFiles(dir_name)
           except OSError, err:
             # must log
             return rr
           # we use the standard python sort order,
           # so 00name is the recommended naming scheme
           dir_contents.sort()
           for relname in dir_contents:
             fname = os.path.join(dir_name, relname)
             if not (os.path.isfile(fname) and os.access(fname, os.X_OK) and
                 self.RE_MASK.match(relname) is not None):
               rrval = constants.HKR_SKIP
               output = ""
             else:
               result, output = self.ExecHook(fname, env)
               if not result:
                 rrval = constants.HKR_FAIL
               else:
                 rrval = constants.HKR_SUCCESS
             rr.append(("%s/%s" % (subdir, relname), rrval, output))
           return rr
       class IAllocatorRunner(object):
         """IAllocator runner.
         This class is instantiated on the node side (ganeti-noded) and not on
         the master side.
         """
         def Run(self, name, idata):
           """Run an iallocator script.
           Return value: tuple of:
              - run status (one of the IARUN_ constants)
              - stdout
              - stderr
              - fail reason (as from utils.RunResult)
           """
           alloc_script = utils.FindFile(name, constants.IALLOCATOR_SEARCH_PATH,
                                         os.path.isfile)
           if alloc_script is None:
             return (constants.IARUN_NOTFOUND, None, None, None)
           fd, fin_name = tempfile.mkstemp(prefix="ganeti-iallocator.")
           try:
             os.write(fd, idata)
             os.close(fd)
             result = utils.RunCmd([alloc_script, fin_name])
             if result.failed:
               return (constants.IARUN_FAILURE, result.stdout, result.stderr,
                       result.fail_reason)
           finally:
             os.unlink(fin_name)
           return (constants.IARUN_SUCCESS, result.stdout, result.stderr, None)
       class DevCacheManager(object):
         """Simple class for managing a cache of block device information.
         """
         _DEV_PREFIX = "/dev/"
         _ROOT_DIR = constants.BDEV_CACHE_DIR
         @classmethod
         def _ConvertPath(cls, dev_path):
           """Converts a /dev/name path to the cache file name.
           This replaces slashes with underscores and strips the /dev
           prefix. It then returns the full path to the cache file
           """
           if dev_path.startswith(cls._DEV_PREFIX):
             dev_path = dev_path[len(cls._DEV_PREFIX):]
           dev_path = dev_path.replace("/", "_")
           fpath = "%s/bdev_%s" % (cls._ROOT_DIR, dev_path)
           return fpath
         @classmethod
         def UpdateCache(cls, dev_path, owner, on_primary, iv_name):
           """Updates the cache information for a given device.
           """
           if dev_path is None:
             logging.error("DevCacheManager.UpdateCache got a None dev_path")
             return
           fpath = cls._ConvertPath(dev_path)
           if on_primary:
             state = "primary"
           else:
             state = "secondary"
           if iv_name is None:
             iv_name = "not_visible"
           fdata = "%s %s %s\n" % (str(owner), state, iv_name)
           try:
             utils.WriteFile(fpath, data=fdata)
           except EnvironmentError, err:
             logging.exception("Can't update bdev cache for %s", dev_path)
         @classmethod
         def RemoveCache(cls, dev_path):
           """Remove data for a dev_path.
           """
           if dev_path is None:
             logging.error("DevCacheManager.RemoveCache got a None dev_path")
             return
           fpath = cls._ConvertPath(dev_path)
           try:
             utils.RemoveFile(fpath)
           except EnvironmentError, err:
             logging.exception("Can't update bdev cache for %s", dev_path)

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root / lib / backend.py @ 7688d0d3