X-Git-Url: https://code.grnet.gr/git/ganeti-local/blobdiff_plain/098c0958281c48228fe57eb7832153dafefbd07c..ec596c24f343013471313ebb05c17581b2f1d970:/lib/rpc.py

diff --git a/lib/rpc.py b/lib/rpc.py
index 061eead..a9619f9 100644
--- a/lib/rpc.py
+++ b/lib/rpc.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#
 #
 
 # Copyright (C) 2006, 2007 Google Inc.
@@ -19,748 +19,968 @@
 # 02110-1301, USA.
 
 
-"""Script to show add a new node to the cluster
+"""Inter-node RPC library.
 
 """
 
-# pylint: disable-msg=C0103
+# 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 logging
+import zlib
+import base64
+
+from ganeti import utils
+from ganeti import objects
+from ganeti import http
+from ganeti import serializer
+from ganeti import constants
+from ganeti import errors
+
+import ganeti.http.client
 
-from twisted.internet.pollreactor import PollReactor
 
-class ReReactor(PollReactor):
-  """A re-startable Reactor implementation.
+# Module level variable
+_http_manager = None
+
+
+def Init():
+  """Initializes the module-global HTTP client manager.
+
+  Must be called before using any RPC function.
 
   """
-  def run(self, installSignalHandlers=1):
-    """Custom run method.
+  global _http_manager
 
-    This is customized run that, before calling Reactor.run, will
-    reinstall the shutdown events and re-create the threadpool in case
-    these are not present (as will happen on the second run of the
-    reactor).
+  assert not _http_manager, "RPC module initialized more than once"
 
-    """
-    if not 'shutdown' in self._eventTriggers:
-      # the shutdown queue has been killed, we are most probably
-      # at the second run, thus recreate the queue
-      self.addSystemEventTrigger('during', 'shutdown', self.crash)
-      self.addSystemEventTrigger('during', 'shutdown', self.disconnectAll)
-    if self.threadpool is not None and self.threadpool.joined == 1:
-      # in case the threadpool has been stopped, re-start it
-      # and add a trigger to stop it at reactor shutdown
-      self.threadpool.start()
-      self.addSystemEventTrigger('during', 'shutdown', self.threadpool.stop)
+  _http_manager = http.client.HttpClientManager()
 
-    return PollReactor.run(self, installSignalHandlers)
 
+def Shutdown():
+  """Stops the module-global HTTP client manager.
 
-import twisted.internet.main
-twisted.internet.main.installReactor(ReReactor())
+  Must be called before quitting the program.
 
-from twisted.spread import pb
-from twisted.internet import reactor
-from twisted.cred import credentials
-from OpenSSL import SSL, crypto
+  """
+  global _http_manager
+
+  if _http_manager:
+    _http_manager.Shutdown()
+    _http_manager = None
 
-from ganeti import logger
-from ganeti import utils
-from ganeti import errors
-from ganeti import constants
-from ganeti import objects
-from ganeti import ssconf
 
-class NodeController:
-  """Node-handling class.
+class RpcResult(object):
+  """RPC Result 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.
+  This class holds an RPC result. It is needed since in multi-node
+  calls we can't raise an exception just because one one out of many
+  failed, and therefore we use this class to encapsulate the result.
+
+  @ivar data: the data payload, for successfull results, or None
+  @type failed: boolean
+  @ivar failed: whether the operation failed at RPC level (not
+      application level on the remote node)
+  @ivar call: the name of the RPC call
+  @ivar node: the name of the node to which we made the call
+  @ivar offline: whether the operation failed because the node was
+      offline, as opposed to actual failure; offline=True will always
+      imply failed=True, in order to allow simpler checking if
+      the user doesn't care about the exact failure mode
 
   """
-  def __init__(self, parent, node):
-    self.parent = parent
+  def __init__(self, data=None, failed=False, offline=False,
+               call=None, node=None):
+    self.failed = failed
+    self.offline = offline
+    self.call = call
     self.node = node
+    if offline:
+      self.failed = True
+      self.error = "Node is marked offline"
+      self.data = None
+    elif failed:
+      self.error = data
+      self.data = None
+    else:
+      self.data = data
+      self.error = None
+
+  def Raise(self):
+    """If the result has failed, raise an OpExecError.
 
-  def _check_end(self):
-    """Stop the reactor if we got all the results.
+    This is used so that LU code doesn't have to check for each
+    result, but instead can call this function.
 
     """
-    if len(self.parent.results) == len(self.parent.nc):
-      reactor.stop()
+    if self.failed:
+      raise errors.OpExecError("Call '%s' to node '%s' has failed: %s" %
+                               (self.call, self.node, self.error))
 
-  def cb_call(self, obj):
-    """Callback for successfull connect.
 
-    If the connect and login sequence succeeded, we proceed with
-    making the actual call.
+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.
+
+  """
+  def __init__(self, procedure, body, port):
+    self.procedure = procedure
+    self.body = body
+    self.port = port
+    self.nc = {}
+
+    self._ssl_params = \
+      http.HttpSslParams(ssl_key_path=constants.SSL_CERT_FILE,
+                         ssl_cert_path=constants.SSL_CERT_FILE)
+
+  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
 
     """
-    deferred = obj.callRemote(self.parent.procedure, self.parent.args)
-    deferred.addCallbacks(self.cb_done, self.cb_err2)
+    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 cb_done(self, result):
-    """Callback for successful call.
+  def ConnectNode(self, name, address=None):
+    """Add a node to the target list.
 
-    When we receive the result from a call, we check if it was an
-    error and if so we raise a generic RemoteError (we can't pass yet
-    the actual exception over). If there was no error, we store the
-    result.
+    @type name: str
+    @param name: the node name
+    @type address: str
+    @keyword address: the node address, if known
 
     """
-    tb, self.parent.results[self.node] = result
-    self._check_end()
-    if tb:
-      raise errors.RemoteError("Remote procedure error calling %s on %s:"
-                               "\n%s" % (self.parent.procedure,
-                                         self.node,
-                                         tb))
+    if address is None:
+      address = name
 
-  def cb_err1(self, reason):
-    """Error callback for unsuccessful connect.
+    self.nc[name] = \
+      http.client.HttpClientRequest(address, self.port, http.HTTP_PUT,
+                                    "/%s" % self.procedure,
+                                    post_data=self.body,
+                                    ssl_params=self._ssl_params,
+                                    ssl_verify_peer=True)
+
+  def GetResults(self):
+    """Call nodes and return results.
+
+    @rtype: list
+    @returns: List of RPC results
 
     """
-    logger.Error("caller_connect: could not connect to remote host %s,"
-                 " reason %s" % (self.node, reason))
-    self.parent.results[self.node] = False
-    self._check_end()
+    assert _http_manager, "RPC module not intialized"
+
+    _http_manager.ExecRequests(self.nc.values())
+
+    results = {}
+
+    for name, req in self.nc.iteritems():
+      if req.success and req.resp_status_code == http.HTTP_OK:
+        results[name] = RpcResult(data=serializer.LoadJson(req.resp_body),
+                                  node=name, call=self.procedure)
+        continue
+
+      # TODO: Better error reporting
+      if req.error:
+        msg = req.error
+      else:
+        msg = req.resp_body
 
-  def cb_err2(self, reason):
-    """Error callback for unsuccessful call.
+      logging.error("RPC error from node %s: %s", name, msg)
+      results[name] = RpcResult(data=msg, failed=True, node=name,
+                                call=self.procedure)
 
-    This is when the call didn't return anything, not even an error,
-    or when it time out, etc.
+    return results
+
+
+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
 
     """
-    logger.Error("caller_call: could not call %s on node %s,"
-                 " reason %s" % (self.parent.procedure, self.node, reason))
-    self.parent.results[self.node] = False
-    self._check_end()
+    self._cfg = cfg
+    self.port = utils.GetNodeDaemonPort()
 
+  def _InstDict(self, instance):
+    """Convert the given instance to a dict.
 
-class MirrorContextFactory:
-  """Certificate verifier factory.
+    This is done via the instance's ToDict() method and additionally
+    we fill the hvparams with the cluster defaults.
 
-  This factory creates contexts that verify if the remote end has a
-  specific certificate (i.e. our own certificate).
+    @type instance: L{objects.Instance}
+    @param instance: an Instance object
+    @rtype: dict
+    @return: the instance dict, with the hvparams filled with the
+        cluster defaults
 
-  The checks we do are that the PEM dump of the certificate is the
-  same as our own and (somewhat redundantly) that the SHA checksum is
-  the same.
+    """
+    idict = instance.ToDict()
+    cluster = self._cfg.GetClusterInfo()
+    idict["hvparams"] = cluster.FillHV(instance)
+    idict["beparams"] = cluster.FillBE(instance)
+    return idict
 
-  """
-  isClient = 1
+  def _ConnectList(self, client, node_list):
+    """Helper for computing node addresses.
 
-  def __init__(self):
-    try:
-      fd = open(constants.SSL_CERT_FILE, 'r')
-      try:
-        data = fd.read(16384)
-      finally:
-        fd.close()
-    except EnvironmentError, err:
-      raise errors.ConfigurationError, ("missing SSL certificate: %s" %
-                                        str(err))
-    self.mycert = crypto.load_certificate(crypto.FILETYPE_PEM, data)
-    self.mypem = crypto.dump_certificate(crypto.FILETYPE_PEM, self.mycert)
-    self.mydigest = self.mycert.digest('SHA')
+    @type client: L{Client}
+    @param client: a C{Client} instance
+    @type node_list: list
+    @param node_list: the node list we should connect
 
-  def verifier(self, conn, x509, errno, err_depth, retcode):
-    """Certificate verify method.
+    """
+    all_nodes = self._cfg.GetAllNodesInfo()
+    name_list = []
+    addr_list = []
+    skip_dict = {}
+    for node in node_list:
+      if node in all_nodes:
+        if all_nodes[node].offline:
+          skip_dict[node] = RpcResult(node=node, offline=True)
+          continue
+        val = all_nodes[node].primary_ip
+      else:
+        val = None
+      addr_list.append(val)
+      name_list.append(node)
+    if name_list:
+      client.ConnectList(name_list, address_list=addr_list)
+    return skip_dict
+
+  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
 
     """
-    if self.mydigest != x509.digest('SHA'):
-      return False
-    if crypto.dump_certificate(crypto.FILETYPE_PEM, x509) != self.mypem:
-      return False
-    return True
+    node_info = self._cfg.GetNodeInfo(node)
+    if node_info is not None:
+      if node_info.offline:
+        return RpcResult(node=node, offline=True)
+      addr = node_info.primary_ip
+    else:
+      addr = None
+    client.ConnectNode(node, address=addr)
 
-  def getContext(self):
-    """Context generator.
+  def _MultiNodeCall(self, node_list, procedure, args):
+    """Helper for making a multi-node call
 
     """
-    context = SSL.Context(SSL.TLSv1_METHOD)
-    context.set_verify(SSL.VERIFY_PEER, self.verifier)
-    return context
+    body = serializer.DumpJson(args, indent=False)
+    c = Client(procedure, body, self.port)
+    skip_dict = self._ConnectList(c, node_list)
+    skip_dict.update(c.GetResults())
+    return skip_dict
 
-class Client:
-  """RPC Client class.
+  @classmethod
+  def _StaticMultiNodeCall(cls, node_list, procedure, args,
+                           address_list=None):
+    """Helper for making a multi-node static call
 
-  This class, given a (remote) ethod 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).
+    """
+    body = serializer.DumpJson(args, indent=False)
+    c = Client(procedure, body, utils.GetNodeDaemonPort())
+    c.ConnectList(node_list, address_list=address_list)
+    return c.GetResults()
 
-  One current bug is that generic failure is still signalled by
-  'False' result, which is not good. This overloading of values can
-  cause bugs.
+  def _SingleNodeCall(self, node, procedure, args):
+    """Helper for making a single-node call
 
-  """
-  result_set = False
-  result = False
-  allresult = []
-
-  def __init__(self, procedure, args):
-    ss = ssconf.SimpleStore()
-    self.port = ss.GetNodeDaemonPort()
-    self.nodepw = ss.GetNodeDaemonPassword()
-    self.nc = {}
-    self.results = {}
-    self.procedure = procedure
-    self.args = args
+    """
+    body = serializer.DumpJson(args, indent=False)
+    c = Client(procedure, body, self.port)
+    result = self._ConnectNode(c, node)
+    if result is None:
+      # we did connect, node is not offline
+      result = c.GetResults()[node]
+    return result
 
-  #--- generic connector -------------
+  @classmethod
+  def _StaticSingleNodeCall(cls, node, procedure, args):
+    """Helper for making a single-node static call
 
-  def connect_list(self, node_list):
-    """Add a list of nodes to the target nodes.
+    """
+    body = serializer.DumpJson(args, indent=False)
+    c = Client(procedure, body, utils.GetNodeDaemonPort())
+    c.ConnectNode(node)
+    return c.GetResults()[node]
+
+  @staticmethod
+  def _Compress(data):
+    """Compresses a string for transport over RPC.
+
+    Small amounts of data are not compressed.
+
+    @type data: str
+    @param data: Data
+    @rtype: tuple
+    @return: Encoded data to send
 
     """
-    for node in node_list:
-      self.connect(node)
+    # Small amounts of data are not compressed
+    if len(data) < 512:
+      return (constants.RPC_ENCODING_NONE, data)
 
-  def connect(self, connect_node):
-    """Add a node to the target list.
+    # Compress with zlib and encode in base64
+    return (constants.RPC_ENCODING_ZLIB_BASE64,
+            base64.b64encode(zlib.compress(data, 3)))
+
+  #
+  # Begin RPC calls
+  #
+
+  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.
 
     """
-    factory = pb.PBClientFactory()
-    self.nc[connect_node] = nc = NodeController(self, connect_node)
-    reactor.connectSSL(connect_node, self.port, factory,
-                       MirrorContextFactory())
-    #d = factory.getRootObject()
-    d = factory.login(credentials.UsernamePassword("master_node", self.nodepw))
-    d.addCallbacks(nc.cb_call, nc.cb_err1)
+    return self._MultiNodeCall(node_list, "volume_list", [vg_name])
 
-  def getresult(self):
-    """Return the results of the call.
+  def call_vg_list(self, node_list):
+    """Gets the volume group list.
+
+    This is a multi-node call.
 
     """
-    return self.results
+    return self._MultiNodeCall(node_list, "vg_list", [])
+
+  def call_bridges_exist(self, node, bridges_list):
+    """Checks if a node has all the bridges given.
 
-  def run(self):
-    """Wrapper over reactor.run().
+    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 function simply calls reactor.run() if we have any requests
-    queued, otherwise it does nothing.
+    This is a single-node call.
 
     """
-    if self.nc:
-      reactor.run()
+    return self._SingleNodeCall(node, "bridges_exist", [bridges_list])
 
+  def call_instance_start(self, node, instance, extra_args):
+    """Starts an instance.
 
-def call_volume_list(node_list, vg_name):
-  """Gets the logical volumes present in a given volume group.
+    This is a single-node call.
 
-  This is a multi-node call.
+    """
+    return self._SingleNodeCall(node, "instance_start",
+                                [self._InstDict(instance), extra_args])
 
-  """
-  c = Client("volume_list", [vg_name])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+  def call_instance_shutdown(self, node, instance):
+    """Stops an instance.
 
+    This is a single-node call.
 
-def call_vg_list(node_list):
-  """Gets the volume group list.
+    """
+    return self._SingleNodeCall(node, "instance_shutdown",
+                                [self._InstDict(instance)])
 
-  This is a multi-node call.
+  def call_instance_migrate(self, node, instance, target, live):
+    """Migrate an instance.
 
-  """
-  c = Client("vg_list", [])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+    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)
 
-def call_bridges_exist(node, bridges_list):
-  """Checks if a node has all the bridges given.
+    """
+    return self._SingleNodeCall(node, "instance_migrate",
+                                [self._InstDict(instance), target, live])
 
-  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.
+  def call_instance_reboot(self, node, instance, reboot_type, extra_args):
+    """Reboots an instance.
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  c = Client("bridges_exist", [bridges_list])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    """
+    return self._SingleNodeCall(node, "instance_reboot",
+                                [self._InstDict(instance), reboot_type,
+                                 extra_args])
 
+  def call_instance_os_add(self, node, inst):
+    """Installs an OS on the given instance.
 
-def call_instance_start(node, instance, extra_args):
-  """Stars an instance.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "instance_os_add",
+                                [self._InstDict(inst)])
 
-  """
-  c = Client("instance_start", [instance.Dumps(), extra_args])
-  c.connect(node)
-  c.run()
-  return c.getresult().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.
 
-def call_instance_shutdown(node, instance):
-  """Stops an instance.
+    """
+    return self._SingleNodeCall(node, "instance_run_rename",
+                                [self._InstDict(inst), old_name])
 
-  This is a single-node call.
+  def call_instance_info(self, node, instance, hname):
+    """Returns information about a single instance.
 
-  """
-  c = Client("instance_shutdown", [instance.Dumps()])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    This is a single-node call.
 
+    @type node: list
+    @param node: 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
 
-def call_instance_os_add(node, inst, osdev, swapdev):
-  """Installs an OS on the given instance.
+    """
+    return self._SingleNodeCall(node, "instance_info", [instance, hname])
 
-  This is a single-node call.
+  def call_all_instances_info(self, node_list, hypervisor_list):
+    """Returns information about all instances on the given nodes.
 
-  """
-  params = [inst.Dumps(), osdev, swapdev]
-  c = Client("instance_os_add", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    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
 
-def call_instance_info(node, instance):
-  """Returns information about a single instance.
+    """
+    return self._MultiNodeCall(node_list, "all_instances_info",
+                               [hypervisor_list])
 
-  This is a single-node call.
+  def call_instance_list(self, node_list, hypervisor_list):
+    """Returns the list of running instances on a given node.
 
-  """
-  c = Client("instance_info", [instance])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    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
 
-def call_all_instances_info(node_list):
-  """Returns information about all instances on a given node.
+    """
+    return self._MultiNodeCall(node_list, "instance_list", [hypervisor_list])
 
-  This is a single-node call.
+  def call_node_tcp_ping(self, node, source, target, port, timeout,
+                         live_port_needed):
+    """Do a TcpPing on the remote node
 
-  """
-  c = Client("all_instances_info", [])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+    This is a single-node call.
 
+    """
+    return self._SingleNodeCall(node, "node_tcp_ping",
+                                [source, target, port, timeout,
+                                 live_port_needed])
 
-def call_instance_list(node_list):
-  """Returns the list of running instances on a given node.
+  def call_node_has_ip_address(self, node, address):
+    """Checks if a node has the given IP address.
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  c = Client("instance_list", [])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+    """
+    return self._SingleNodeCall(node, "node_has_ip_address", [address])
 
+  def call_node_info(self, node_list, vg_name, hypervisor_type):
+    """Return node information.
 
-def call_node_info(node_list, vg_name):
-  """Return node information.
+    This will return memory information and volume group size and free
+    space.
 
-  This will return memory information and volume group size and free
-  space.
+    This is a multi-node call.
 
-  This is a multi-node call.
+    @type node_list: list
+    @param node_list: the list of nodes to query
+    @type vg_name: C{string}
+    @param vg_name: 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])
-  c.connect_list(node_list)
-  c.run()
-  retux = c.getresult()
+    """
+    retux = self._MultiNodeCall(node_list, "node_info",
+                                [vg_name, hypervisor_type])
 
-  for node_name in retux:
-    ret = retux.get(node_name, False)
-    if type(ret) != dict:
-      logger.Error("could not connect to node %s" % (node_name))
-      ret = {}
+    for result in retux.itervalues():
+      if result.failed or not isinstance(result.data, dict):
+        result.data = {}
 
-    utils.CheckDict(ret,
-                    { 'memory_total' : '-',
-                      'memory_dom0' : '-',
-                      'memory_free' : '-',
-                      'vg_size' : 'node_unreachable',
-                      'vg_free' : '-' },
-                    "call_node_info",
-                    )
-  return retux
+      utils.CheckDict(result.data, {
+        '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.
 
-def call_node_add(node, dsa, dsapub, rsa, rsapub, ssh, sshpub):
-  """Add a node to the cluster.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "node_add",
+                                [dsa, dsapub, rsa, rsapub, ssh, sshpub])
 
-  """
-  params = [dsa, dsapub, rsa, rsapub, ssh, sshpub]
-  c = Client("node_add", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+  def call_node_verify(self, node_list, checkdict, cluster_name):
+    """Request verification of given parameters.
 
+    This is a multi-node call.
 
-def call_node_verify(node_list, checkdict):
-  """Request verification of given parameters.
+    """
+    return self._MultiNodeCall(node_list, "node_verify",
+                               [checkdict, cluster_name])
 
-  This is a multi-node call.
+  @classmethod
+  def call_node_start_master(cls, node, start_daemons):
+    """Tells a node to activate itself as a master.
 
-  """
-  c = Client("node_verify", [checkdict])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+    This is a single-node call.
 
+    """
+    return cls._StaticSingleNodeCall(node, "node_start_master",
+                                     [start_daemons])
 
-def call_node_start_master(node):
-  """Tells a node to activate itself as a master.
+  @classmethod
+  def call_node_stop_master(cls, node, stop_daemons):
+    """Tells a node to demote itself from master status.
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  c = Client("node_start_master", [])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    """
+    return cls._StaticSingleNodeCall(node, "node_stop_master", [stop_daemons])
 
+  @classmethod
+  def call_master_info(cls, node_list):
+    """Query master info.
 
-def call_node_stop_master(node):
-  """Tells a node to demote itself from master status.
+    This is a multi-node call.
 
-  This is a single-node call.
+    """
+    # TODO: should this method query down nodes?
+    return cls._StaticMultiNodeCall(node_list, "master_info", [])
 
-  """
-  c = Client("node_stop_master", [])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+  def call_version(self, node_list):
+    """Query node version.
 
+    This is a multi-node call.
 
-def call_version(node_list):
-  """Query node version.
+    """
+    return self._MultiNodeCall(node_list, "version", [])
 
-  This is a multi-node call.
+  def call_blockdev_create(self, node, bdev, size, owner, on_primary, info):
+    """Request creation of a given block device.
 
-  """
-  c = Client("version", [])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+    This is a single-node call.
 
+    """
+    return self._SingleNodeCall(node, "blockdev_create",
+                                [bdev.ToDict(), size, owner, on_primary, info])
 
-def call_blockdev_create(node, bdev, size, on_primary):
-  """Request creation of a given block device.
+  def call_blockdev_remove(self, node, bdev):
+    """Request removal of a given block device.
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  params = [bdev.Dumps(), size, on_primary]
-  c = Client("blockdev_create", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    """
+    return self._SingleNodeCall(node, "blockdev_remove", [bdev.ToDict()])
 
+  def call_blockdev_rename(self, node, devlist):
+    """Request rename of the given block devices.
 
-def call_blockdev_remove(node, bdev):
-  """Request removal of a given block device.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "blockdev_rename",
+                                [(d.ToDict(), uid) for d, uid in devlist])
 
-  """
-  c = Client("blockdev_remove", [bdev.Dumps()])
-  c.connect(node)
-  c.run()
-  return c.getresult().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.
 
-def call_blockdev_assemble(node, disk, on_primary):
-  """Request assembling of a given block device.
+    """
+    return self._SingleNodeCall(node, "blockdev_assemble",
+                                [disk.ToDict(), owner, on_primary])
 
-  This is a single-node call.
+  def call_blockdev_shutdown(self, node, disk):
+    """Request shutdown of a given block device.
 
-  """
-  params = [disk.Dumps(), on_primary]
-  c = Client("blockdev_assemble", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    This is a single-node call.
 
+    """
+    return self._SingleNodeCall(node, "blockdev_shutdown", [disk.ToDict()])
 
-def call_blockdev_shutdown(node, disk):
-  """Request shutdown of a given block device.
+  def call_blockdev_addchildren(self, node, bdev, ndevs):
+    """Request adding a list of children to a (mirroring) device.
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  c = Client("blockdev_shutdown", [disk.Dumps()])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    """
+    return self._SingleNodeCall(node, "blockdev_addchildren",
+                                [bdev.ToDict(),
+                                 [disk.ToDict() for disk in ndevs]])
 
+  def call_blockdev_removechildren(self, node, bdev, ndevs):
+    """Request removing a list of children from a (mirroring) device.
 
-def call_blockdev_addchild(node, bdev, ndev):
-  """Request adding a new child to a (mirroring) device.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "blockdev_removechildren",
+                                [bdev.ToDict(),
+                                 [disk.ToDict() for disk in ndevs]])
 
-  """
-  params = [bdev.Dumps(), ndev.Dumps()]
-  c = Client("blockdev_addchild", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+  def call_blockdev_getmirrorstatus(self, node, disks):
+    """Request status of a (mirroring) device.
 
+    This is a single-node call.
 
-def call_blockdev_removechild(node, bdev, ndev):
-  """Request removing a new child from a (mirroring) device.
+    """
+    return self._SingleNodeCall(node, "blockdev_getmirrorstatus",
+                                [dsk.ToDict() for dsk in disks])
 
-  This is a single-node call.
+  def call_blockdev_find(self, node, disk):
+    """Request identification of a given block device.
 
-  """
-  params = [bdev.Dumps(), ndev.Dumps()]
-  c = Client("blockdev_removechild", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    This is a single-node call.
 
+    """
+    return self._SingleNodeCall(node, "blockdev_find", [disk.ToDict()])
 
-def call_blockdev_getmirrorstatus(node, disks):
-  """Request status of a (mirroring) device.
+  def call_blockdev_close(self, node, disks):
+    """Closes the given block devices.
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  params = [dsk.Dumps() for dsk in disks]
-  c = Client("blockdev_getmirrorstatus", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    """
+    return self._SingleNodeCall(node, "blockdev_close",
+                                [cf.ToDict() for cf in disks])
 
+  @classmethod
+  def call_upload_file(cls, node_list, file_name, address_list=None):
+    """Upload a file.
 
-def call_blockdev_find(node, disk):
-  """Request identification of a given block device.
+    The node will refuse the operation in case the file is not on the
+    approved file list.
 
-  This is a single-node call.
+    This is a multi-node call.
 
-  """
-  c = Client("blockdev_find", [disk.Dumps()])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    @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
 
+    """
+    file_contents = utils.ReadFile(file_name)
+    data = cls._Compress(file_contents)
+    st = os.stat(file_name)
+    params = [file_name, data, st.st_mode, st.st_uid, st.st_gid,
+              st.st_atime, st.st_mtime]
+    return cls._StaticMultiNodeCall(node_list, "upload_file", params,
+                                    address_list=address_list)
 
-def call_upload_file(node_list, file_name):
-  """Upload a file.
+  @classmethod
+  def call_write_ssconf_files(cls, node_list, values):
+    """Write ssconf files.
 
-  The node will refuse the operation in case the file is not on the
-  approved file list.
+    This is a multi-node call.
 
-  This is a multi-node call.
+    """
+    return cls._StaticMultiNodeCall(node_list, "write_ssconf_files", [values])
 
-  """
-  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.connect_list(node_list)
-  c.run()
-  return c.getresult()
+  def call_os_diagnose(self, node_list):
+    """Request a diagnose of OS definitions.
 
+    This is a multi-node call.
 
-def call_os_diagnose(node_list):
-  """Request a diagnose of OS definitions.
+    """
+    result = self._MultiNodeCall(node_list, "os_diagnose", [])
 
-  This is a multi-node call.
+    for node_result in result.values():
+      if not node_result.failed and node_result.data:
+        node_result.data = [objects.OS.FromDict(oss)
+                            for oss in node_result.data]
+    return result
 
-  """
-  c = Client("os_diagnose", [])
-  c.connect_list(node_list)
-  c.run()
-  result = c.getresult()
-  new_result = {}
-  for node_name in result:
-    nr = []
-    if result[node_name]:
-      for data in result[node_name]:
-        if data:
-          if isinstance(data, basestring):
-            nr.append(objects.ConfigObject.Loads(data))
-          elif isinstance(data, tuple) and len(data) == 2:
-            nr.append(errors.InvalidOS(data[0], data[1]))
-          else:
-            raise errors.ProgrammerError, ("Invalid data from"
-                                           " xcserver.os_diagnose")
-    new_result[node_name] = nr
-  return new_result
-
-
-def call_os_get(node_list, name):
-  """Returns an OS definition.
-
-  This is a multi-node call.
+  def call_os_get(self, node, name):
+    """Returns an OS definition.
 
-  """
-  c = Client("os_get", [name])
-  c.connect_list(node_list)
-  c.run()
-  result = c.getresult()
-  new_result = {}
-  for node_name in result:
-    data = result[node_name]
-    if isinstance(data, basestring):
-      new_result[node_name] = objects.ConfigObject.Loads(data)
-    elif isinstance(data, tuple) and len(data) == 2:
-      new_result[node_name] = errors.InvalidOS(data[0], data[1])
-    else:
-      new_result[node_name] = data
-  return new_result
+    This is a single-node call.
 
+    """
+    result = self._SingleNodeCall(node, "os_get", [name])
+    if not result.failed and isinstance(result.data, dict):
+      result.data = objects.OS.FromDict(result.data)
+    return result
 
-def call_hooks_runner(node_list, hpath, phase, env):
-  """Call the hooks runner.
+  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
+    Args:
+      - op: the OpCode instance
+      - env: a dictionary with the environment
 
-  This is a multi-node call.
+    This is a multi-node call.
 
-  """
-  params = [hpath, phase, env]
-  c = Client("hooks_runner", params)
-  c.connect_list(node_list)
-  c.run()
-  result = c.getresult()
-  return result
+    """
+    params = [hpath, phase, env]
+    return self._MultiNodeCall(node_list, "hooks_runner", params)
 
+  def call_iallocator_runner(self, node, name, idata):
+    """Call an iallocator on a remote node
 
-def call_blockdev_snapshot(node, cf_bdev):
-  """Request a snapshot of the given block device.
+    Args:
+      - name: the iallocator name
+      - input: the json-encoded input string
 
-  This is a single-node call.
+    This is a single-node call.
 
-  """
-  c = Client("blockdev_snapshot", [cf_bdev.Dumps()])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    """
+    return self._SingleNodeCall(node, "iallocator_runner", [name, idata])
 
+  def call_blockdev_grow(self, node, cf_bdev, amount):
+    """Request a snapshot of the given block device.
 
-def call_snapshot_export(node, snap_bdev, dest_node, instance):
-  """Request the export of a given snapshot.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "blockdev_grow",
+                                [cf_bdev.ToDict(), amount])
 
-  """
-  params = [snap_bdev.Dumps(), dest_node, instance.Dumps()]
-  c = Client("snapshot_export", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().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.
 
+    """
+    return self._SingleNodeCall(node, "blockdev_snapshot", [cf_bdev.ToDict()])
 
-def call_finalize_export(node, instance, snap_disks):
-  """Request the completion of an export operation.
+  def call_snapshot_export(self, node, snap_bdev, dest_node, instance,
+                           cluster_name, idx):
+    """Request the export of a given snapshot.
 
-  This writes the export config file, etc.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "snapshot_export",
+                                [snap_bdev.ToDict(), dest_node,
+                                 self._InstDict(instance), cluster_name, idx])
 
-  """
-  flat_disks = []
-  for disk in snap_disks:
-    flat_disks.append(disk.Dumps())
-  params = [instance.Dumps(), flat_disks]
-  c = Client("finalize_export", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().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.
 
-def call_export_info(node, path):
-  """Queries the export information in a given path.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    flat_disks = []
+    for disk in snap_disks:
+      flat_disks.append(disk.ToDict())
 
-  """
-  c = Client("export_info", [path])
-  c.connect(node)
-  c.run()
-  result = c.getresult().get(node, False)
-  if not result:
+    return self._SingleNodeCall(node, "finalize_export",
+                                [self._InstDict(instance), flat_disks])
+
+  def call_export_info(self, node, path):
+    """Queries the export information in a given path.
+
+    This is a single-node call.
+
+    """
+    result = self._SingleNodeCall(node, "export_info", [path])
+    if not result.failed and result.data:
+      result.data = objects.SerializableConfigParser.Loads(str(result.data))
     return result
-  return objects.SerializableConfigParser.Loads(result)
 
+  def call_instance_os_import(self, node, inst, src_node, src_images,
+                              cluster_name):
+    """Request the import of a backup into an instance.
 
-def call_instance_os_import(node, inst, osdev, swapdev, src_node, src_image):
-  """Request the import of a backup into an instance.
+    This is a single-node call.
 
-  This is a single-node call.
+    """
+    return self._SingleNodeCall(node, "instance_os_import",
+                                [self._InstDict(inst), src_node, src_images,
+                                 cluster_name])
 
-  """
-  params = [inst.Dumps(), osdev, swapdev, src_node, src_image]
-  c = Client("instance_os_import", params)
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+  def call_export_list(self, node_list):
+    """Gets the stored exports list.
 
+    This is a multi-node call.
 
-def call_export_list(node_list):
-  """Gets the stored exports list.
+    """
+    return self._MultiNodeCall(node_list, "export_list", [])
 
-  This is a multi-node call.
+  def call_export_remove(self, node, export):
+    """Requests removal of a given export.
 
-  """
-  c = Client("export_list", [])
-  c.connect_list(node_list)
-  c.run()
-  result = c.getresult()
-  return result
+    This is a single-node call.
 
+    """
+    return self._SingleNodeCall(node, "export_remove", [export])
 
-def call_export_remove(node, export):
-  """Requests removal of a given export.
+  @classmethod
+  def call_node_leave_cluster(cls, node):
+    """Requests a node to clean the cluster information it has.
 
-  This is a single-node call.
+    This will remove the configuration information from the ganeti data
+    dir.
 
-  """
-  c = Client("export_remove", [export])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+    This is a single-node call.
 
+    """
+    return cls._StaticSingleNodeCall(node, "node_leave_cluster", [])
 
-def call_node_leave_cluster(node):
-  """Requests a node to clean the cluster information it has.
+  def call_node_volumes(self, node_list):
+    """Gets all volumes on node(s).
 
-  This will remove the configuration information from the ganeti data
-  dir.
+    This is a multi-node call.
 
-  This is a single-node call.
+    """
+    return self._MultiNodeCall(node_list, "node_volumes", [])
 
-  """
-  c = Client("node_leave_cluster", [])
-  c.connect(node)
-  c.run()
-  return c.getresult().get(node, False)
+  def call_node_demote_from_mc(self, node):
+    """Demote a node from the master candidate role.
 
+    This is a single-node call.
 
-def call_node_volumes(node_list):
-  """Gets all volumes on node(s).
+    """
+    return self._SingleNodeCall(node, "node_demote_from_mc", [])
 
-  This is a multi-node call.
+  def call_test_delay(self, node_list, duration):
+    """Sleep for a fixed time on given node(s).
 
-  """
-  c = Client("node_volumes", [])
-  c.connect_list(node_list)
-  c.run()
-  return c.getresult()
+    This is a multi-node call.
+
+    """
+    return self._MultiNodeCall(node_list, "test_delay", [duration])
+
+  def call_file_storage_dir_create(self, node, file_storage_dir):
+    """Create the given file storage directory.
+
+    This is a single-node call.
+
+    """
+    return self._SingleNodeCall(node, "file_storage_dir_create",
+                                [file_storage_dir])
+
+  def call_file_storage_dir_remove(self, node, file_storage_dir):
+    """Remove the given file storage directory.
+
+    This is a single-node call.
+
+    """
+    return self._SingleNodeCall(node, "file_storage_dir_remove",
+                                [file_storage_dir])
+
+  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.
+
+    """
+    return self._SingleNodeCall(node, "file_storage_dir_rename",
+                                [old_file_storage_dir, new_file_storage_dir])
+
+  @classmethod
+  def call_jobqueue_update(cls, node_list, address_list, file_name, content):
+    """Update job queue.
+
+    This is a multi-node call.
+
+    """
+    return cls._StaticMultiNodeCall(node_list, "jobqueue_update",
+                                    [file_name, cls._Compress(content)],
+                                    address_list=address_list)
+
+  @classmethod
+  def call_jobqueue_purge(cls, node):
+    """Purge job queue.
+
+    This is a single-node call.
+
+    """
+    return cls._StaticSingleNodeCall(node, "jobqueue_purge", [])
+
+  @classmethod
+  def call_jobqueue_rename(cls, node_list, address_list, rename):
+    """Rename a job queue file.
+
+    This is a multi-node call.
+
+    """
+    return cls._StaticMultiNodeCall(node_list, "jobqueue_rename", rename,
+                                    address_list=address_list)
+
+  @classmethod
+  def call_jobqueue_set_drain(cls, 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.
+
+    """
+    return cls._StaticMultiNodeCall(node_list, "jobqueue_set_drain",
+                                    [drain_flag])
+
+  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)
+    return self._MultiNodeCall(node_list, "hypervisor_validate_params",
+                               [hvname, hv_full])