Replace string values with proper constants
[ganeti-local] / lib / config.py
index c1c857b..d2b9c56 100644 (file)
@@ -1,7 +1,7 @@
 #
 #
 
-# Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Google Inc.
+# Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 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
@@ -50,6 +50,8 @@ from ganeti import serializer
 from ganeti import uidpool
 from ganeti import netutils
 from ganeti import runtime
+from ganeti import pathutils
+from ganeti import network
 
 
 _config_lock = locking.SharedLock("ConfigWriter")
@@ -106,6 +108,17 @@ class TemporaryReservationManager:
       all_reserved.update(holder_reserved)
     return all_reserved
 
+  def GetECReserved(self, ec_id):
+    """ Used when you want to retrieve all reservations for a specific
+        execution context. E.g when commiting reserved IPs for a specific
+        network.
+
+    """
+    ec_reserved = set()
+    if ec_id in self._ec_reserved:
+      ec_reserved.update(self._ec_reserved[ec_id])
+    return ec_reserved
+
   def Generate(self, existing, generate_one_fn, ec_id):
     """Generate a new resource of this type
 
@@ -133,6 +146,26 @@ def _MatchNameComponentIgnoreCase(short_name, names):
   return utils.MatchNameComponent(short_name, names, case_sensitive=False)
 
 
+def _CheckInstanceDiskIvNames(disks):
+  """Checks if instance's disks' C{iv_name} attributes are in order.
+
+  @type disks: list of L{objects.Disk}
+  @param disks: List of disks
+  @rtype: list of tuples; (int, string, string)
+  @return: List of wrongly named disks, each tuple contains disk index,
+    expected and actual name
+
+  """
+  result = []
+
+  for (idx, disk) in enumerate(disks):
+    exp_iv_name = "disk/%s" % idx
+    if disk.iv_name != exp_iv_name:
+      result.append((idx, exp_iv_name, disk.iv_name))
+
+  return result
+
+
 class ConfigWriter:
   """The interface to the cluster configuration.
 
@@ -147,7 +180,7 @@ class ConfigWriter:
     self._config_data = None
     self._offline = offline
     if cfg_file is None:
-      self._cfg_file = constants.CLUSTER_CONF_FILE
+      self._cfg_file = pathutils.CLUSTER_CONF_FILE
     else:
       self._cfg_file = cfg_file
     self._getents = _getents
@@ -156,8 +189,10 @@ class ConfigWriter:
     self._temporary_macs = TemporaryReservationManager()
     self._temporary_secrets = TemporaryReservationManager()
     self._temporary_lvs = TemporaryReservationManager()
+    self._temporary_ips = TemporaryReservationManager()
     self._all_rms = [self._temporary_ids, self._temporary_macs,
-                     self._temporary_secrets, self._temporary_lvs]
+                     self._temporary_secrets, self._temporary_lvs,
+                     self._temporary_ips]
     # Note: in order to prevent errors when resolving our name in
     # _DistributeConfig, we compute it here once and reuse it; it's
     # better to raise an error before starting to modify the config
@@ -186,18 +221,7 @@ class ConfigWriter:
     """Check if the cluster is configured.
 
     """
-    return os.path.exists(constants.CLUSTER_CONF_FILE)
-
-  def _GenerateOneMAC(self):
-    """Generate one mac address
-
-    """
-    prefix = self._config_data.cluster.mac_prefix
-    byte1 = random.randrange(0, 256)
-    byte2 = random.randrange(0, 256)
-    byte3 = random.randrange(0, 256)
-    mac = "%s:%02x:%02x:%02x" % (prefix, byte1, byte2, byte3)
-    return mac
+    return os.path.exists(pathutils.CLUSTER_CONF_FILE)
 
   @locking.ssynchronized(_config_lock, shared=1)
   def GetNdParams(self, node):
@@ -212,14 +236,82 @@ class ConfigWriter:
     return self._config_data.cluster.FillND(node, nodegroup)
 
   @locking.ssynchronized(_config_lock, shared=1)
-  def GenerateMAC(self, ec_id):
+  def GetInstanceDiskParams(self, instance):
+    """Get the disk params populated with inherit chain.
+
+    @type instance: L{objects.Instance}
+    @param instance: The instance we want to know the params for
+    @return: A dict with the filled in disk params
+
+    """
+    node = self._UnlockedGetNodeInfo(instance.primary_node)
+    nodegroup = self._UnlockedGetNodeGroup(node.group)
+    return self._UnlockedGetGroupDiskParams(nodegroup)
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetGroupDiskParams(self, group):
+    """Get the disk params populated with inherit chain.
+
+    @type group: L{objects.NodeGroup}
+    @param group: The group we want to know the params for
+    @return: A dict with the filled in disk params
+
+    """
+    return self._UnlockedGetGroupDiskParams(group)
+
+  def _UnlockedGetGroupDiskParams(self, group):
+    """Get the disk params populated with inherit chain down to node-group.
+
+    @type group: L{objects.NodeGroup}
+    @param group: The group we want to know the params for
+    @return: A dict with the filled in disk params
+
+    """
+    return self._config_data.cluster.SimpleFillDP(group.diskparams)
+
+  def _UnlockedGetNetworkMACPrefix(self, net):
+    """Return the network mac prefix if it exists or the cluster level default.
+
+    """
+    prefix = None
+    if net:
+      net_uuid = self._UnlockedLookupNetwork(net)
+      if net_uuid:
+        nobj = self._UnlockedGetNetwork(net_uuid)
+        if nobj.mac_prefix:
+          prefix = nobj.mac_prefix
+
+    return prefix
+
+  def _GenerateOneMAC(self, prefix=None):
+    """Return a function that randomly generates a MAC suffic
+       and appends it to the given prefix. If prefix is not given get
+       the cluster level default.
+
+    """
+    if not prefix:
+      prefix = self._config_data.cluster.mac_prefix
+
+    def GenMac():
+      byte1 = random.randrange(0, 256)
+      byte2 = random.randrange(0, 256)
+      byte3 = random.randrange(0, 256)
+      mac = "%s:%02x:%02x:%02x" % (prefix, byte1, byte2, byte3)
+      return mac
+
+    return GenMac
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GenerateMAC(self, net, ec_id):
     """Generate a MAC for an instance.
 
     This should check the current instances for duplicates.
 
     """
     existing = self._AllMACs()
-    return self._temporary_ids.Generate(existing, self._GenerateOneMAC, ec_id)
+    prefix = self._UnlockedGetNetworkMACPrefix(net)
+    gen_mac = self._GenerateOneMAC(prefix)
+    return self._temporary_ids.Generate(existing, gen_mac, ec_id)
 
   @locking.ssynchronized(_config_lock, shared=1)
   def ReserveMAC(self, mac, ec_id):
@@ -235,6 +327,93 @@ class ConfigWriter:
     else:
       self._temporary_macs.Reserve(ec_id, mac)
 
+  def _UnlockedCommitTemporaryIps(self, ec_id):
+    """Commit all reserved IP address to their respective pools
+
+    """
+    for action, address, net_uuid in self._temporary_ips.GetECReserved(ec_id):
+      self._UnlockedCommitIp(action, net_uuid, address)
+
+  def _UnlockedCommitIp(self, action, net_uuid, address):
+    """Commit a reserved IP address to an IP pool.
+
+    The IP address is taken from the network's IP pool and marked as reserved.
+
+    """
+    nobj = self._UnlockedGetNetwork(net_uuid)
+    pool = network.AddressPool(nobj)
+    if action == constants.RESERVE_ACTION:
+      pool.Reserve(address)
+    elif action == constants.RELEASE_ACTION:
+      pool.Release(address)
+
+  def _UnlockedReleaseIp(self, net_uuid, address, ec_id):
+    """Give a specific IP address back to an IP pool.
+
+    The IP address is returned to the IP pool designated by pool_id and marked
+    as reserved.
+
+    """
+    self._temporary_ips.Reserve(ec_id,
+                                (constants.RELEASE_ACTION, address, net_uuid))
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def ReleaseIp(self, net, address, ec_id):
+    """Give a specified IP address back to an IP pool.
+
+    This is just a wrapper around _UnlockedReleaseIp.
+
+    """
+    net_uuid = self._UnlockedLookupNetwork(net)
+    if net_uuid:
+      self._UnlockedReleaseIp(net_uuid, address, ec_id)
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GenerateIp(self, net, ec_id):
+    """Find a free IPv4 address for an instance.
+
+    """
+    net_uuid = self._UnlockedLookupNetwork(net)
+    nobj = self._UnlockedGetNetwork(net_uuid)
+    pool = network.AddressPool(nobj)
+    gen_free = pool.GenerateFree()
+
+    def gen_one():
+      try:
+        ip = gen_free()
+      except StopIteration:
+        raise errors.ReservationError("Cannot generate IP. Network is full")
+      return (constants.RESERVE_ACTION, ip, net_uuid)
+
+    _, address, _ = self._temporary_ips.Generate([], gen_one, ec_id)
+    return address
+
+  def _UnlockedReserveIp(self, net_uuid, address, ec_id):
+    """Reserve a given IPv4 address for use by an instance.
+
+    """
+    nobj = self._UnlockedGetNetwork(net_uuid)
+    pool = network.AddressPool(nobj)
+    try:
+      isreserved = pool.IsReserved(address)
+    except errors.AddressPoolError:
+      raise errors.ReservationError("IP address not in network")
+    if isreserved:
+      raise errors.ReservationError("IP address already in use")
+
+    return self._temporary_ips.Reserve(ec_id,
+                                       (constants.RESERVE_ACTION,
+                                        address, net_uuid))
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def ReserveIp(self, net, address, ec_id):
+    """Reserve a given IPv4 address for use by an instance.
+
+    """
+    net_uuid = self._UnlockedLookupNetwork(net)
+    if net_uuid:
+      return self._UnlockedReserveIp(net_uuid, address, ec_id)
+
   @locking.ssynchronized(_config_lock, shared=1)
   def ReserveLV(self, lv_name, ec_id):
     """Reserve an VG/LV pair for an instance.
@@ -426,6 +605,28 @@ class ConfigWriter:
       except errors.ConfigurationError, err:
         result.append("%s has invalid nicparams: %s" % (owner, err))
 
+    def _helper_ipolicy(owner, params, check_std):
+      try:
+        objects.InstancePolicy.CheckParameterSyntax(params, check_std)
+      except errors.ConfigurationError, err:
+        result.append("%s has invalid instance policy: %s" % (owner, err))
+
+    def _helper_ispecs(owner, params):
+      for key, value in params.items():
+        if key in constants.IPOLICY_ISPECS:
+          fullkey = "ipolicy/" + key
+          _helper(owner, fullkey, value, constants.ISPECS_PARAMETER_TYPES)
+        else:
+          # FIXME: assuming list type
+          if key in constants.IPOLICY_PARAMETERS:
+            exp_type = float
+          else:
+            exp_type = list
+          if not isinstance(value, exp_type):
+            result.append("%s has invalid instance policy: for %s,"
+                          " expecting %s, got %s" %
+                          (owner, key, exp_type.__name__, type(value)))
+
     # check cluster parameters
     _helper("cluster", "beparams", cluster.SimpleFillBE({}),
             constants.BES_PARAMETER_TYPES)
@@ -434,6 +635,8 @@ class ConfigWriter:
     _helper_nic("cluster", cluster.SimpleFillNIC({}))
     _helper("cluster", "ndparams", cluster.SimpleFillND({}),
             constants.NDS_PARAMETER_TYPES)
+    _helper_ipolicy("cluster", cluster.SimpleFillIPolicy({}), True)
+    _helper_ispecs("cluster", cluster.SimpleFillIPolicy({}))
 
     # per-instance checks
     for instance_name in data.instances:
@@ -467,12 +670,12 @@ class ConfigWriter:
                 cluster.FillBE(instance), constants.BES_PARAMETER_TYPES)
 
       # gather the drbd ports for duplicate checks
-      for dsk in instance.disks:
+      for (idx, dsk) in enumerate(instance.disks):
         if dsk.dev_type in constants.LDS_DRBD:
           tcp_port = dsk.logical_id[2]
           if tcp_port not in ports:
             ports[tcp_port] = []
-          ports[tcp_port].append((instance.name, "drbd disk %s" % dsk.iv_name))
+          ports[tcp_port].append((instance.name, "drbd disk %s" % idx))
       # gather network port reservation
       net_port = getattr(instance, "network_port", None)
       if net_port is not None:
@@ -486,6 +689,15 @@ class ConfigWriter:
                        (instance.name, idx, msg) for msg in disk.Verify()])
         result.extend(self._CheckDiskIDs(disk, seen_lids, seen_pids))
 
+      wrong_names = _CheckInstanceDiskIvNames(instance.disks)
+      if wrong_names:
+        tmp = "; ".join(("name of disk %s should be '%s', but is '%s'" %
+                         (idx, exp_name, actual_name))
+                        for (idx, exp_name, actual_name) in wrong_names)
+
+        result.append("Instance '%s' has wrongly named disks: %s" %
+                      (instance.name, tmp))
+
     # cluster-wide pool of free ports
     for free_port in cluster.tcpudp_port_pool:
       if free_port not in ports:
@@ -548,8 +760,12 @@ class ConfigWriter:
         result.append("duplicate node group name '%s'" % nodegroup.name)
       else:
         nodegroups_names.add(nodegroup.name)
+      group_name = "group %s" % nodegroup.name
+      _helper_ipolicy(group_name, cluster.SimpleFillIPolicy(nodegroup.ipolicy),
+                      False)
+      _helper_ispecs(group_name, cluster.SimpleFillIPolicy(nodegroup.ipolicy))
       if nodegroup.ndparams:
-        _helper("group %s" % nodegroup.name, "ndparams",
+        _helper(group_name, "ndparams",
                 cluster.SimpleFillND(nodegroup.ndparams),
                 constants.NDS_PARAMETER_TYPES)
 
@@ -589,7 +805,7 @@ class ConfigWriter:
         else:
           raise errors.ProgrammerError("NIC mode '%s' not handled" % nic_mode)
 
-        _AddIpAddress("%s/%s" % (link, nic.ip),
+        _AddIpAddress("%s/%s/%s" % (link, nic.ip, nic.network),
                       "instance:%s/nic:%d" % (instance.name, idx))
 
     for ip, owners in ips.items():
@@ -667,12 +883,15 @@ class ConfigWriter:
   def AddTcpUdpPort(self, port):
     """Adds a new port to the available port pool.
 
+    @warning: this method does not "flush" the configuration (via
+        L{_WriteConfig}); callers should do that themselves once the
+        configuration is stable
+
     """
     if not isinstance(port, int):
       raise errors.ProgrammerError("Invalid type passed for port")
 
     self._config_data.cluster.tcpudp_port_pool.add(port)
-    self._WriteConfig()
 
   @locking.ssynchronized(_config_lock, shared=1)
   def GetPortList(self):
@@ -960,10 +1179,9 @@ class ConfigWriter:
 
     """
     cluster = self._config_data.cluster
-    result = objects.MasterNetworkParameters(name=cluster.master_node,
-      ip=cluster.master_ip,
-      netmask=cluster.master_netmask,
-      netdev=cluster.master_netdev,
+    result = objects.MasterNetworkParameters(
+      name=cluster.master_node, ip=cluster.master_ip,
+      netmask=cluster.master_netmask, netdev=cluster.master_netdev,
       ip_family=cluster.primary_ip_family)
 
     return result
@@ -1050,7 +1268,7 @@ class ConfigWriter:
     if target is None:
       if len(self._config_data.nodegroups) != 1:
         raise errors.OpPrereqError("More than one node group exists. Target"
-                                   " group must be specified explicitely.")
+                                   " group must be specified explicitly.")
       else:
         return self._config_data.nodegroups.keys()[0]
     if target in self._config_data.nodegroups:
@@ -1126,6 +1344,17 @@ class ConfigWriter:
                      for member_name in
                        self._UnlockedGetNodeGroup(ngfn(node_name)).members)
 
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetMultiNodeGroupInfo(self, group_uuids):
+    """Get the configuration of multiple node groups.
+
+    @param group_uuids: List of node group UUIDs
+    @rtype: list
+    @return: List of tuples of (group_uuid, group_info)
+
+    """
+    return [(uuid, self._UnlockedGetNodeGroup(uuid)) for uuid in group_uuids]
+
   @locking.ssynchronized(_config_lock)
   def AddInstance(self, instance, ec_id):
     """Add an instance to the config.
@@ -1157,6 +1386,7 @@ class ConfigWriter:
     self._config_data.instances[instance.name] = instance
     self._config_data.cluster.serial_no += 1
     self._UnlockedReleaseDRBDMinors(instance.name)
+    self._UnlockedCommitTemporaryIps(ec_id)
     self._WriteConfig()
 
   def _EnsureUUID(self, item, ec_id):
@@ -1218,6 +1448,15 @@ class ConfigWriter:
     if network_port is not None:
       self._config_data.cluster.tcpudp_port_pool.add(network_port)
 
+    instance = self._UnlockedGetInstanceInfo(instance_name)
+
+    for nic in instance.nics:
+      if nic.network is not None and nic.ip is not None:
+        net_uuid = self._UnlockedLookupNetwork(nic.network)
+        if net_uuid:
+          # Return all IP addresses to the respective address pools
+          self._UnlockedCommitIp(constants.RELEASE_ACTION, net_uuid, nic.ip)
+
     del self._config_data.instances[instance_name]
     self._config_data.cluster.serial_no += 1
     self._WriteConfig()
@@ -1233,24 +1472,27 @@ class ConfigWriter:
     """
     if old_name not in self._config_data.instances:
       raise errors.ConfigurationError("Unknown instance '%s'" % old_name)
-    inst = self._config_data.instances[old_name]
-    del self._config_data.instances[old_name]
+
+    # Operate on a copy to not loose instance object in case of a failure
+    inst = self._config_data.instances[old_name].Copy()
     inst.name = new_name
 
-    for disk in inst.disks:
+    for (idx, disk) in enumerate(inst.disks):
       if disk.dev_type == constants.LD_FILE:
         # rename the file paths in logical and physical id
         file_storage_dir = os.path.dirname(os.path.dirname(disk.logical_id[1]))
-        disk_fname = "disk%s" % disk.iv_name.split("/")[1]
-        disk.physical_id = disk.logical_id = (disk.logical_id[0],
-                                              utils.PathJoin(file_storage_dir,
-                                                             inst.name,
-                                                             disk_fname))
+        disk.logical_id = (disk.logical_id[0],
+                           utils.PathJoin(file_storage_dir, inst.name,
+                                          "disk%s" % idx))
+        disk.physical_id = disk.logical_id
+
+    # Actually replace instance object
+    del self._config_data.instances[old_name]
+    self._config_data.instances[inst.name] = inst
 
     # Force update of ssconf files
     self._config_data.cluster.serial_no += 1
 
-    self._config_data.instances[inst.name] = inst
     self._WriteConfig()
 
   @locking.ssynchronized(_config_lock)
@@ -1682,7 +1924,7 @@ class ConfigWriter:
     """Changes the group of a number of nodes.
 
     @type mods: list of tuples; (node name, new group UUID)
-    @param modes: Node membership modifications
+    @param mods: Node membership modifications
 
     """
     groups = self._config_data.nodegroups
@@ -1780,8 +2022,8 @@ class ConfigWriter:
     # Make sure the configuration has the right version
     _ValidateConfig(data)
 
-    if (not hasattr(data, 'cluster') or
-        not hasattr(data.cluster, 'rsahostkeypub')):
+    if (not hasattr(data, "cluster") or
+        not hasattr(data.cluster, "rsahostkeypub")):
       raise errors.ConfigurationError("Incomplete configuration"
                                       " (missing cluster.rsahostkeypub)")
 
@@ -1986,6 +2228,9 @@ class ConfigWriter:
     nodegroups = ["%s %s" % (nodegroup.uuid, nodegroup.name) for nodegroup in
                   self._config_data.nodegroups.values()]
     nodegroups_data = fn(utils.NiceSort(nodegroups))
+    networks = ["%s %s" % (net.uuid, net.name) for net in
+                self._config_data.networks.values()]
+    networks_data = fn(utils.NiceSort(networks))
 
     ssconf_values = {
       constants.SS_CLUSTER_NAME: cluster.cluster_name,
@@ -2010,6 +2255,7 @@ class ConfigWriter:
       constants.SS_MAINTAIN_NODE_HEALTH: str(cluster.maintain_node_health),
       constants.SS_UID_POOL: uid_pool,
       constants.SS_NODEGROUPS: nodegroups_data,
+      constants.SS_NETWORKS: networks_data,
       }
     bad_values = [(k, v) for k, v in ssconf_values.items()
                   if not isinstance(v, (str, basestring))]
@@ -2083,7 +2329,7 @@ class ConfigWriter:
     return self._config_data.HasAnyDiskOfType(dev_type)
 
   @locking.ssynchronized(_config_lock)
-  def Update(self, target, feedback_fn):
+  def Update(self, target, feedback_fn, ec_id=None):
     """Notify function to be called after updates.
 
     This function must be called when an object (as returned by
@@ -2111,6 +2357,8 @@ class ConfigWriter:
       test = target in self._config_data.instances.values()
     elif isinstance(target, objects.NodeGroup):
       test = target in self._config_data.nodegroups.values()
+    elif isinstance(target, objects.Network):
+      test = target in self._config_data.networks.values()
     else:
       raise errors.ProgrammerError("Invalid object type (%s) passed to"
                                    " ConfigWriter.Update" % type(target))
@@ -2128,6 +2376,10 @@ class ConfigWriter:
     if isinstance(target, objects.Instance):
       self._UnlockedReleaseDRBDMinors(target.name)
 
+    if ec_id is not None:
+      # Commit all ips reserved by OpInstanceSetParams and OpGroupSetParams
+      self._UnlockedCommitTemporaryIps(ec_id)
+
     self._WriteConfig(feedback_fn=feedback_fn)
 
   @locking.ssynchronized(_config_lock)
@@ -2137,3 +2389,195 @@ class ConfigWriter:
     """
     for rm in self._all_rms:
       rm.DropECReservations(ec_id)
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetAllNetworksInfo(self):
+    """Get the configuration of all networks
+
+    """
+    return dict(self._config_data.networks)
+
+  def _UnlockedGetNetworkList(self):
+    """Get the list of networks.
+
+    This function is for internal use, when the config lock is already held.
+
+    """
+    return self._config_data.networks.keys()
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetNetworkList(self):
+    """Get the list of networks.
+
+    @return: array of networks, ex. ["main", "vlan100", "200]
+
+    """
+    return self._UnlockedGetNetworkList()
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetNetworkNames(self):
+    """Get a list of network names
+
+    """
+    names = [net.name
+             for net in self._config_data.networks.values()]
+    return names
+
+  def _UnlockedGetNetwork(self, uuid):
+    """Returns information about a network.
+
+    This function is for internal use, when the config lock is already held.
+
+    """
+    if uuid not in self._config_data.networks:
+      return None
+
+    return self._config_data.networks[uuid]
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetNetwork(self, uuid):
+    """Returns information about a network.
+
+    It takes the information from the configuration file.
+
+    @param uuid: UUID of the network
+
+    @rtype: L{objects.Network}
+    @return: the network object
+
+    """
+    return self._UnlockedGetNetwork(uuid)
+
+  @locking.ssynchronized(_config_lock)
+  def AddNetwork(self, net, ec_id, check_uuid=True):
+    """Add a network to the configuration.
+
+    @type net: L{objects.Network}
+    @param net: the Network object to add
+    @type ec_id: string
+    @param ec_id: unique id for the job to use when creating a missing UUID
+
+    """
+    self._UnlockedAddNetwork(net, ec_id, check_uuid)
+    self._WriteConfig()
+
+  def _UnlockedAddNetwork(self, net, ec_id, check_uuid):
+    """Add a network to the configuration.
+
+    """
+    logging.info("Adding network %s to configuration", net.name)
+
+    if check_uuid:
+      self._EnsureUUID(net, ec_id)
+
+    existing_uuid = self._UnlockedLookupNetwork(net.name)
+    if existing_uuid:
+      raise errors.OpPrereqError("Desired network name '%s' already"
+                                 " exists as a network (UUID: %s)" %
+                                 (net.name, existing_uuid),
+                                 errors.ECODE_EXISTS)
+    net.serial_no = 1
+    self._config_data.networks[net.uuid] = net
+    self._config_data.cluster.serial_no += 1
+
+  def _UnlockedLookupNetwork(self, target):
+    """Lookup a network's UUID.
+
+    @type target: string
+    @param target: network name or UUID
+    @rtype: string
+    @return: network UUID
+    @raises errors.OpPrereqError: when the target network cannot be found
+
+    """
+    if target in self._config_data.networks:
+      return target
+    for net in self._config_data.networks.values():
+      if net.name == target:
+        return net.uuid
+    return None
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def LookupNetwork(self, target):
+    """Lookup a network's UUID.
+
+    This function is just a wrapper over L{_UnlockedLookupNetwork}.
+
+    @type target: string
+    @param target: network name or UUID
+    @rtype: string
+    @return: network UUID
+
+    """
+    return self._UnlockedLookupNetwork(target)
+
+  @locking.ssynchronized(_config_lock)
+  def RemoveNetwork(self, network_uuid):
+    """Remove a network from the configuration.
+
+    @type network_uuid: string
+    @param network_uuid: the UUID of the network to remove
+
+    """
+    logging.info("Removing network %s from configuration", network_uuid)
+
+    if network_uuid not in self._config_data.networks:
+      raise errors.ConfigurationError("Unknown network '%s'" % network_uuid)
+
+    del self._config_data.networks[network_uuid]
+    self._config_data.cluster.serial_no += 1
+    self._WriteConfig()
+
+  def _UnlockedGetGroupNetParams(self, net, node):
+    """Get the netparams (mode, link) of a network.
+
+    Get a network's netparams for a given node.
+
+    @type net: string
+    @param net: network name
+    @type node: string
+    @param node: node name
+    @rtype: dict or None
+    @return: netparams
+
+    """
+    net_uuid = self._UnlockedLookupNetwork(net)
+    if net_uuid is None:
+      return None
+
+    node_info = self._UnlockedGetNodeInfo(node)
+    nodegroup_info = self._UnlockedGetNodeGroup(node_info.group)
+    netparams = nodegroup_info.networks.get(net_uuid, None)
+
+    return netparams
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def GetGroupNetParams(self, net, node):
+    """Locking wrapper of _UnlockedGetGroupNetParams()
+
+    """
+    return self._UnlockedGetGroupNetParams(net, node)
+
+  @locking.ssynchronized(_config_lock, shared=1)
+  def CheckIPInNodeGroup(self, ip, node):
+    """Check for conflictig IP.
+
+    @type ip: string
+    @param ip: ip address
+    @type node: string
+    @param node: node name
+    @rtype: (string, dict) or (None, None)
+    @return: (network name, netparams)
+
+    """
+    if ip is None:
+      return (None, None)
+    node_info = self._UnlockedGetNodeInfo(node)
+    nodegroup_info = self._UnlockedGetNodeGroup(node_info.group)
+    for net_uuid in nodegroup_info.networks.keys():
+      net_info = self._UnlockedGetNetwork(net_uuid)
+      pool = network.AddressPool(net_info)
+      if pool.Contains(ip):
+        return (net_info.name, nodegroup_info.networks[net_uuid])
+
+    return (None, None)