Synnefo » snf-ganeti

#

#

# 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.

"""Inter-node RPC library.

"""

# pylint: disable-msg=C0103,R0201,R0904

# C0103: Invalid name, since call_ are not valid

# R0201: Method could be a function, we keep all rpcs instance methods

# as not to change them back and forth between static/instance methods

# if they need to start using instance attributes

# R0904: Too many public methods

import os

import socket

import httplib

import logging

import simplejson

from ganeti import utils

from ganeti import objects

class NodeController:

  """Node-handling class.

  For each node that we speak with, we create an instance of this

  class, so that we have a safe place to store the details of this

  individual call.

  """

  def __init__(self, parent, node, address=None):

    """Constructor for the node controller.

    @type parent: L{Client}

    @param parent: the C{Client} instance which holds global parameters for

        the call

    @type node: str

    @param node: the name of the node we connect to; it is used for error

        messages and in cases we the address paramater is not passed

    @type address: str

    @keyword address: the node's address, in case we know it, so that we

        don't need to resolve it; testing shows that httplib has high

        overhead in resolving addresses (even when speficied in /etc/hosts)

    """

    self.parent = parent

    self.node = node

    if address is None:

      address = node

    self.failed = False

    self.http_conn = hc = httplib.HTTPConnection(address, parent.port)

    try:

      hc.connect()

      hc.putrequest('PUT', "/%s" % parent.procedure,

                    skip_accept_encoding=True)

      hc.putheader('Content-Length', parent.body_length)

      hc.endheaders()

      hc.send(parent.body)

    except socket.error:

      logging.exception("Error connecting to node %s", node)

      self.failed = True

  def GetResponse(self):

    """Try to process the response from the node.

    """

    if self.failed:

      # we already failed in connect

      return False

    resp = self.http_conn.getresponse()

    if resp.status != 200:

      return False

    try:

      length = int(resp.getheader('Content-Length', '0'))

    except ValueError:

      return False

    if not length:

      logging.error("Zero-length reply from node %s", self.node)

      return False

    payload = resp.read(length)

    unload = simplejson.loads(payload)

    return unload

class Client:

  """RPC Client class.

  This class, given a (remote) method name, a list of parameters and a

  list of nodes, will contact (in parallel) all nodes, and return a

  dict of results (key: node name, value: result).

  One current bug is that generic failure is still signalled by

  'False' result, which is not good. This overloading of values can

  cause bugs.

  @var body_length: cached string value of the length of the body (so that

      individual C{NodeController} instances don't have to recompute it)

  """

  result_set = False

  result = False

  allresult = []

  def __init__(self, procedure, args):

    self.port = utils.GetNodeDaemonPort()

    self.nodepw = utils.GetNodeDaemonPassword()

    self.nc = {}

    self.results = {}

    self.procedure = procedure

    self.args = args

    self.body = simplejson.dumps(args)

    self.body_length = str(len(self.body))

  #--- generic connector -------------

  def ConnectList(self, node_list, address_list=None):

    """Add a list of nodes to the target nodes.

    @type node_list: list

    @param node_list: the list of node names to connect

    @type address_list: list or None

    @keyword address_list: either None or a list with node addresses,

        which must have the same length as the node list

    """

    if address_list is None:

      address_list = [None for _ in node_list]

    else:

      assert len(node_list) == len(address_list), \

             "Name and address lists should have the same length"

    for node, address in zip(node_list, address_list):

      self.ConnectNode(node, address)

  def ConnectNode(self, name, address=None):

    """Add a node to the target list.

    @type name: str

    @param name: the node name

    @type address: str

    @keyword address: the node address, if known

    """

    self.nc[name] = NodeController(self, name, address)

  def GetResults(self):

    """Return the results of the call.

    """

    return self.results

  def Run(self):

    """Gather results from the node controllers.

    This function simply calls GetResponse() for each of our node

    controllers.

    """

    for node, nc in self.nc.items():

      self.results[node] = nc.GetResponse()

class RpcRunner(object):

  """RPC runner class"""

  def __init__(self, cfg):

    """Initialized the rpc runner.

    @type cfg:  C{config.ConfigWriter}

    @param cfg: the configuration object that will be used to get data

                about the cluster

    """

    self._cfg = cfg

  def _InstDict(self, instance):

    """Convert the given instance to a dict.

    This is done via the instance's ToDict() method and additionally

    we fill the hvparams with the cluster defaults.

    @type instance: L{objects.Instance}

    @param instance: an Instance object

    @rtype: dict

    @return: the instance dict, with the hvparams filled with the

        cluster defaults

    """

    idict = instance.ToDict()

    cluster = self._cfg.GetClusterInfo()

    idict["hvparams"] = cluster.FillHV(instance)

    idict["beparams"] = cluster.FillBE(instance)

    return idict

  def _ConnectList(self, client, node_list):

    """Helper for computing node addresses.

    @type client: L{Client}

    @param client: a C{Client} instance

    @type node_list: list

    @param node_list: the node list we should connect

    """

    all_nodes = self._cfg.GetAllNodesInfo()

    addr_list = []

    for node in node_list:

      if node in all_nodes:

        val = all_nodes[node].primary_ip

      else:

        val = None

      addr_list.append(val)

    client.ConnectList(node_list, address_list=addr_list)

  def _ConnectNode(self, client, node):

    """Helper for computing one node's address.

    @type client: L{Client}

    @param client: a C{Client} instance

    @type node: str

    @param node: the node we should connect

    """

    node_info = self._cfg.GetNodeInfo(node)

    if node_info is not None:

      addr = node_info.primary_ip

    else:

      addr = None

    client.ConnectNode(node, address=addr)

  def call_volume_list(self, node_list, vg_name):

    """Gets the logical volumes present in a given volume group.

    This is a multi-node call.

    """

    c = Client("volume_list", [vg_name])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_vg_list(self, node_list):

    """Gets the volume group list.

    This is a multi-node call.

    """

    c = Client("vg_list", [])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_bridges_exist(self, node, bridges_list):

    """Checks if a node has all the bridges given.

    This method checks if all bridges given in the bridges_list are

    present on the remote node, so that an instance that uses interfaces

    on those bridges can be started.

    This is a single-node call.

    """

    c = Client("bridges_exist", [bridges_list])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_start(self, node, instance, extra_args):

    """Starts an instance.

    This is a single-node call.

    """

    c = Client("instance_start", [self._InstDict(instance), extra_args])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_shutdown(self, node, instance):

    """Stops an instance.

    This is a single-node call.

    """

    c = Client("instance_shutdown", [self._InstDict(instance)])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_migrate(self, node, instance, target, live):

    """Migrate an instance.

    This is a single-node call.

    @type node: string

    @param node: the node on which the instance is currently running

    @type instance: C{objects.Instance}

    @param instance: the instance definition

    @type target: string

    @param target: the target node name

    @type live: boolean

    @param live: whether the migration should be done live or not (the

        interpretation of this parameter is left to the hypervisor)

    """

    c = Client("instance_migrate", [self._InstDict(instance), target, live])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_reboot(self, node, instance, reboot_type, extra_args):

    """Reboots an instance.

    This is a single-node call.

    """

    c = Client("instance_reboot", [self._InstDict(instance),

                                   reboot_type, extra_args])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_os_add(self, node, inst):

    """Installs an OS on the given instance.

    This is a single-node call.

    """

    params = [self._InstDict(inst)]

    c = Client("instance_os_add", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_run_rename(self, node, inst, old_name):

    """Run the OS rename script for an instance.

    This is a single-node call.

    """

    params = [self._InstDict(inst), old_name]

    c = Client("instance_run_rename", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_instance_info(self, node, instance, hname):

    """Returns information about a single instance.

    This is a single-node call.

    @type node_list: list

    @param node_list: the list of nodes to query

    @type instance: string

    @param instance: the instance name

    @type hname: string

    @param hname: the hypervisor type of the instance

    """

    c = Client("instance_info", [instance, hname])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_all_instances_info(self, node_list, hypervisor_list):

    """Returns information about all instances on the given nodes.

    This is a multi-node call.

    @type node_list: list

    @param node_list: the list of nodes to query

    @type hypervisor_list: list

    @param hypervisor_list: the hypervisors to query for instances

    """

    c = Client("all_instances_info", [hypervisor_list])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_instance_list(self, node_list, hypervisor_list):

    """Returns the list of running instances on a given node.

    This is a multi-node call.

    @type node_list: list

    @param node_list: the list of nodes to query

    @type hypervisor_list: list

    @param hypervisor_list: the hypervisors to query for instances

    """

    c = Client("instance_list", [hypervisor_list])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_node_tcp_ping(self, node, source, target, port, timeout,

                         live_port_needed):

    """Do a TcpPing on the remote node

    This is a single-node call.

    """

    c = Client("node_tcp_ping", [source, target, port, timeout,

                                 live_port_needed])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_node_has_ip_address(self, node, address):

    """Checks if a node has the given IP address.

    This is a single-node call.

    """

    c = Client("node_has_ip_address", [address])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_node_info(self, node_list, vg_name, hypervisor_type):

    """Return node information.

    This will return memory information and volume group size and free

    space.

    This is a multi-node call.

    @type node_list: list

    @param node_list: the list of nodes to query

    @type vgname: C{string}

    @param vgname: the name of the volume group to ask for disk space

        information

    @type hypervisor_type: C{str}

    @param hypervisor_type: the name of the hypervisor to ask for

        memory information

    """

    c = Client("node_info", [vg_name, hypervisor_type])

    self._ConnectList(c, node_list)

    c.Run()

    retux = c.GetResults()

    for node_name in retux:

      ret = retux.get(node_name, False)

      if type(ret) != dict:

        logging.error("could not connect to node %s", node_name)

        ret = {}

      utils.CheckDict(ret,

                      { 'memory_total' : '-',

                        'memory_dom0' : '-',

                        'memory_free' : '-',

                        'vg_size' : 'node_unreachable',

                        'vg_free' : '-' },

                      "call_node_info",

                      )

    return retux

  def call_node_add(self, node, dsa, dsapub, rsa, rsapub, ssh, sshpub):

    """Add a node to the cluster.

    This is a single-node call.

    """

    params = [dsa, dsapub, rsa, rsapub, ssh, sshpub]

    c = Client("node_add", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_node_verify(self, node_list, checkdict, cluster_name):

    """Request verification of given parameters.

    This is a multi-node call.

    """

    c = Client("node_verify", [checkdict, cluster_name])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  @staticmethod

  def call_node_start_master(node, start_daemons):

    """Tells a node to activate itself as a master.

    This is a single-node call.

    """

    c = Client("node_start_master", [start_daemons])

    c.ConnectNode(node)

    c.Run()

    return c.GetResults().get(node, False)

  @staticmethod

  def call_node_stop_master(node, stop_daemons):

    """Tells a node to demote itself from master status.

    This is a single-node call.

    """

    c = Client("node_stop_master", [stop_daemons])

    c.ConnectNode(node)

    c.Run()

    return c.GetResults().get(node, False)

  @staticmethod

  def call_master_info(node_list):

    """Query master info.

    This is a multi-node call.

    """

    # TODO: should this method query down nodes?

    c = Client("master_info", [])

    c.ConnectList(node_list)

    c.Run()

    return c.GetResults()

  def call_version(self, node_list):

    """Query node version.

    This is a multi-node call.

    """

    c = Client("version", [])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_blockdev_create(self, node, bdev, size, owner, on_primary, info):

    """Request creation of a given block device.

    This is a single-node call.

    """

    params = [bdev.ToDict(), size, owner, on_primary, info]

    c = Client("blockdev_create", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_remove(self, node, bdev):

    """Request removal of a given block device.

    This is a single-node call.

    """

    c = Client("blockdev_remove", [bdev.ToDict()])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_rename(self, node, devlist):

    """Request rename of the given block devices.

    This is a single-node call.

    """

    params = [(d.ToDict(), uid) for d, uid in devlist]

    c = Client("blockdev_rename", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_assemble(self, node, disk, owner, on_primary):

    """Request assembling of a given block device.

    This is a single-node call.

    """

    params = [disk.ToDict(), owner, on_primary]

    c = Client("blockdev_assemble", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_shutdown(self, node, disk):

    """Request shutdown of a given block device.

    This is a single-node call.

    """

    c = Client("blockdev_shutdown", [disk.ToDict()])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_addchildren(self, node, bdev, ndevs):

    """Request adding a list of children to a (mirroring) device.

    This is a single-node call.

    """

    params = [bdev.ToDict(), [disk.ToDict() for disk in ndevs]]

    c = Client("blockdev_addchildren", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_removechildren(self, node, bdev, ndevs):

    """Request removing a list of children from a (mirroring) device.

    This is a single-node call.

    """

    params = [bdev.ToDict(), [disk.ToDict() for disk in ndevs]]

    c = Client("blockdev_removechildren", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_getmirrorstatus(self, node, disks):

    """Request status of a (mirroring) device.

    This is a single-node call.

    """

    params = [dsk.ToDict() for dsk in disks]

    c = Client("blockdev_getmirrorstatus", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_find(self, node, disk):

    """Request identification of a given block device.

    This is a single-node call.

    """

    c = Client("blockdev_find", [disk.ToDict()])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_close(self, node, disks):

    """Closes the given block devices.

    This is a single-node call.

    """

    params = [cf.ToDict() for cf in disks]

    c = Client("blockdev_close", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  @staticmethod

  def call_upload_file(node_list, file_name, address_list=None):

    """Upload a file.

    The node will refuse the operation in case the file is not on the

    approved file list.

    This is a multi-node call.

    @type node_list: list

    @param node_list: the list of node names to upload to

    @type file_name: str

    @param file_name: the filename to upload

    @type address_list: list or None

    @keyword address_list: an optional list of node addresses, in order

        to optimize the RPC speed

    """

    fh = file(file_name)

    try:

      data = fh.read()

    finally:

      fh.close()

    st = os.stat(file_name)

    params = [file_name, data, st.st_mode, st.st_uid, st.st_gid,

              st.st_atime, st.st_mtime]

    c = Client("upload_file", params)

    c.ConnectList(node_list, address_list=address_list)

    c.Run()

    return c.GetResults()

  def call_os_diagnose(self, node_list):

    """Request a diagnose of OS definitions.

    This is a multi-node call.

    """

    c = Client("os_diagnose", [])

    self._ConnectList(c, node_list)

    c.Run()

    result = c.GetResults()

    new_result = {}

    for node_name in result:

      if result[node_name]:

        nr = [objects.OS.FromDict(oss) for oss in result[node_name]]

      else:

        nr = []

      new_result[node_name] = nr

    return new_result

  def call_os_get(self, node, name):

    """Returns an OS definition.

    This is a single-node call.

    """

    c = Client("os_get", [name])

    self._ConnectNode(c, node)

    c.Run()

    result = c.GetResults().get(node, False)

    if isinstance(result, dict):

      return objects.OS.FromDict(result)

    else:

      return result

  def call_hooks_runner(self, node_list, hpath, phase, env):

    """Call the hooks runner.

    Args:

      - op: the OpCode instance

      - env: a dictionary with the environment

    This is a multi-node call.

    """

    params = [hpath, phase, env]

    c = Client("hooks_runner", params)

    self._ConnectList(c, node_list)

    c.Run()

    result = c.GetResults()

    return result

  def call_iallocator_runner(self, node, name, idata):

    """Call an iallocator on a remote node

    Args:

      - name: the iallocator name

      - input: the json-encoded input string

    This is a single-node call.

    """

    params = [name, idata]

    c = Client("iallocator_runner", params)

    self._ConnectNode(c, node)

    c.Run()

    result = c.GetResults().get(node, False)

    return result

  def call_blockdev_grow(self, node, cf_bdev, amount):

    """Request a snapshot of the given block device.

    This is a single-node call.

    """

    c = Client("blockdev_grow", [cf_bdev.ToDict(), amount])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_blockdev_snapshot(self, node, cf_bdev):

    """Request a snapshot of the given block device.

    This is a single-node call.

    """

    c = Client("blockdev_snapshot", [cf_bdev.ToDict()])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_snapshot_export(self, node, snap_bdev, dest_node, instance,

                           cluster_name):

    """Request the export of a given snapshot.

    This is a single-node call.

    """

    params = [snap_bdev.ToDict(), dest_node,

              self._InstDict(instance), cluster_name]

    c = Client("snapshot_export", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_finalize_export(self, node, instance, snap_disks):

    """Request the completion of an export operation.

    This writes the export config file, etc.

    This is a single-node call.

    """

    flat_disks = []

    for disk in snap_disks:

      flat_disks.append(disk.ToDict())

    params = [self._InstDict(instance), flat_disks]

    c = Client("finalize_export", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_export_info(self, node, path):

    """Queries the export information in a given path.

    This is a single-node call.

    """

    c = Client("export_info", [path])

    self._ConnectNode(c, node)

    c.Run()

    result = c.GetResults().get(node, False)

    if not result:

      return result

    return objects.SerializableConfigParser.Loads(str(result))

  def call_instance_os_import(self, node, inst, osdev, swapdev,

                              src_node, src_image, cluster_name):

    """Request the import of a backup into an instance.

    This is a single-node call.

    """

    params = [self._InstDict(inst), osdev, swapdev,

              src_node, src_image, cluster_name]

    c = Client("instance_os_import", params)

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_export_list(self, node_list):

    """Gets the stored exports list.

    This is a multi-node call.

    """

    c = Client("export_list", [])

    self._ConnectList(c, node_list)

    c.Run()

    result = c.GetResults()

    return result

  def call_export_remove(self, node, export):

    """Requests removal of a given export.

    This is a single-node call.

    """

    c = Client("export_remove", [export])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  @staticmethod

  def call_node_leave_cluster(node):

    """Requests a node to clean the cluster information it has.

    This will remove the configuration information from the ganeti data

    dir.

    This is a single-node call.

    """

    c = Client("node_leave_cluster", [])

    c.ConnectNode(node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_node_volumes(self, node_list):

    """Gets all volumes on node(s).

    This is a multi-node call.

    """

    c = Client("node_volumes", [])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_test_delay(self, node_list, duration):

    """Sleep for a fixed time on given node(s).

    This is a multi-node call.

    """

    c = Client("test_delay", [duration])

    self._ConnectList(c, node_list)

    c.Run()

    return c.GetResults()

  def call_file_storage_dir_create(self, node, file_storage_dir):

    """Create the given file storage directory.

    This is a single-node call.

    """

    c = Client("file_storage_dir_create", [file_storage_dir])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_file_storage_dir_remove(self, node, file_storage_dir):

    """Remove the given file storage directory.

    This is a single-node call.

    """

    c = Client("file_storage_dir_remove", [file_storage_dir])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  def call_file_storage_dir_rename(self, node, old_file_storage_dir,

                                   new_file_storage_dir):

    """Rename file storage directory.

    This is a single-node call.

    """

    c = Client("file_storage_dir_rename",

               [old_file_storage_dir, new_file_storage_dir])

    self._ConnectNode(c, node)

    c.Run()

    return c.GetResults().get(node, False)

  @staticmethod

  def call_jobqueue_update(node_list, file_name, content):

    """Update job queue.

    This is a multi-node call.

    """

    c = Client("jobqueue_update", [file_name, content])

    c.ConnectList(node_list)

    c.Run()

    result = c.GetResults()

    return result

  @staticmethod

  def call_jobqueue_purge(node):

    """Purge job queue.

    This is a single-node call.

    """

    c = Client("jobqueue_purge", [])

    c.ConnectNode(node)

    c.Run()

    return c.GetResults().get(node, False)

  @staticmethod

  def call_jobqueue_rename(node_list, old, new):

    """Rename a job queue file.

    This is a multi-node call.

    """

    c = Client("jobqueue_rename", [old, new])

    c.ConnectList(node_list)

    c.Run()

    result = c.GetResults()

    return result

  @staticmethod

  def call_jobqueue_set_drain(node_list, drain_flag):

    """Set the drain flag on the queue.

    This is a multi-node call.

    @type node_list: list

    @param node_list: the list of nodes to query

    @type drain_flag: bool

    @param drain_flag: if True, will set the drain flag, otherwise reset it.

    """

    c = Client("jobqueue_set_drain", [drain_flag])

    c.ConnectList(node_list)

    c.Run()

    result = c.GetResults()

    return result

  def call_hypervisor_validate_params(self, node_list, hvname, hvparams):

    """Validate the hypervisor params.

    This is a multi-node call.

    @type node_list: list

    @param node_list: the list of nodes to query

    @type hvname: string

    @param hvname: the hypervisor name

    @type hvparams: dict

    @param hvparams: the hypervisor parameters to be validated

    """

    cluster = self._cfg.GetClusterInfo()

    hv_full = cluster.FillDict(cluster.hvparams.get(hvname, {}), hvparams)

    c = Client("hypervisor_validate_params", [hvname, hv_full])

    self._ConnectList(c, node_list)

    c.Run()

    result = c.GetResults()

    return result