gnt-instance

#!/usr/bin/python
#

# Copyright (C) 2006, 2007 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.


# pylint: disable-msg=W0401,W0614
# W0401: Wildcard import ganeti.cli
# W0614: Unused import %s from wildcard import (since we need cli)

import sys
import os
import itertools
import simplejson
import time
from optparse import make_option
from cStringIO import StringIO

from ganeti.cli import *
from ganeti import cli
from ganeti import opcodes
from ganeti import constants
from ganeti import utils
from ganeti import errors


_SHUTDOWN_CLUSTER = "cluster"
_SHUTDOWN_NODES_BOTH = "nodes"
_SHUTDOWN_NODES_PRI = "nodes-pri"
_SHUTDOWN_NODES_SEC = "nodes-sec"
_SHUTDOWN_INSTANCES = "instances"


_VALUE_TRUE = "true"

#: default list of options for L{ListInstances}
_LIST_DEF_FIELDS = [
  "name", "hypervisor", "os", "pnode", "status", "oper_ram",
  ]


def _ExpandMultiNames(mode, names, client=None):
  """Expand the given names using the passed mode.

  For _SHUTDOWN_CLUSTER, all instances will be returned. For
  _SHUTDOWN_NODES_PRI/SEC, all instances having those nodes as
  primary/secondary will be returned. For _SHUTDOWN_NODES_BOTH, all
  instances having those nodes as either primary or secondary will be
  returned. For _SHUTDOWN_INSTANCES, the given instances will be
  returned.

  @param mode: one of L{_SHUTDOWN_CLUSTER}, L{_SHUTDOWN_NODES_BOTH},
      L{_SHUTDOWN_NODES_PRI}, L{_SHUTDOWN_NODES_SEC} or
      L{_SHUTDOWN_INSTANCES}
  @param names: a list of names; for cluster, it must be empty,
      and for node and instance it must be a list of valid item
      names (short names are valid as usual, e.g. node1 instead of
      node1.example.com)
  @rtype: list
  @return: the list of names after the expansion
  @raise errors.ProgrammerError: for unknown selection type
  @raise errors.OpPrereqError: for invalid input parameters

  """
  if client is None:
    client = GetClient()
  if mode == _SHUTDOWN_CLUSTER:
    if names:
      raise errors.OpPrereqError("Cluster filter mode takes no arguments")
    idata = client.QueryInstances([], ["name"], False)
    inames = [row[0] for row in idata]

  elif mode in (_SHUTDOWN_NODES_BOTH,
                _SHUTDOWN_NODES_PRI,
                _SHUTDOWN_NODES_SEC):
    if not names:
      raise errors.OpPrereqError("No node names passed")
    ndata = client.QueryNodes(names, ["name", "pinst_list", "sinst_list"],
                              False)
    ipri = [row[1] for row in ndata]
    pri_names = list(itertools.chain(*ipri))
    isec = [row[2] for row in ndata]
    sec_names = list(itertools.chain(*isec))
    if mode == _SHUTDOWN_NODES_BOTH:
      inames = pri_names + sec_names
    elif mode == _SHUTDOWN_NODES_PRI:
      inames = pri_names
    elif mode == _SHUTDOWN_NODES_SEC:
      inames = sec_names
    else:
      raise errors.ProgrammerError("Unhandled shutdown type")

  elif mode == _SHUTDOWN_INSTANCES:
    if not names:
      raise errors.OpPrereqError("No instance names passed")
    idata = client.QueryInstances(names, ["name"], False)
    inames = [row[0] for row in idata]

  else:
    raise errors.OpPrereqError("Unknown mode '%s'" % mode)

  return inames


def _ConfirmOperation(inames, text, extra=""):
  """Ask the user to confirm an operation on a list of instances.

  This function is used to request confirmation for doing an operation
  on a given list of instances.

  @type inames: list
  @param inames: the list of names that we display when
      we ask for confirmation
  @type text: str
  @param text: the operation that the user should confirm
      (e.g. I{shutdown} or I{startup})
  @rtype: boolean
  @return: True or False depending on user's confirmation.

  """
  count = len(inames)
  msg = ("The %s will operate on %d instances.\n%s"
         "Do you want to continue?" % (text, count, extra))
  affected = ("\nAffected instances:\n" +
              "\n".join(["  %s" % name for name in inames]))

  choices = [('y', True, 'Yes, execute the %s' % text),
             ('n', False, 'No, abort the %s' % text)]

  if count > 20:
    choices.insert(1, ('v', 'v', 'View the list of affected instances'))
    ask = msg
  else:
    ask = msg + affected

  choice = AskUser(ask, choices)
  if choice == 'v':
    choices.pop(1)
    choice = AskUser(msg + affected, choices)
  return choice


def _EnsureInstancesExist(client, names):
  """Check for and ensure the given instance names exist.

  This function will raise an OpPrereqError in case they don't
  exist. Otherwise it will exit cleanly.

  @type client: L{ganeti.luxi.Client}
  @param client: the client to use for the query
  @type names: list
  @param names: the list of instance names to query
  @raise errors.OpPrereqError: in case any instance is missing

  """
  # TODO: change LUQueryInstances to that it actually returns None
  # instead of raising an exception, or devise a better mechanism
  result = client.QueryInstances(names, ["name"], False)
  for orig_name, row in zip(names, result):
    if row[0] is None:
      raise errors.OpPrereqError("Instance '%s' does not exist" % orig_name)


def ListInstances(opts, args):
  """List instances and their properties.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should be an empty list
  @rtype: int
  @return: the desired exit code

  """
  if opts.output is None:
    selected_fields = _LIST_DEF_FIELDS
  elif opts.output.startswith("+"):
    selected_fields = _LIST_DEF_FIELDS + opts.output[1:].split(",")
  else:
    selected_fields = opts.output.split(",")

  output = GetClient().QueryInstances(args, selected_fields, opts.do_locking)

  if not opts.no_headers:
    headers = {
      "name": "Instance", "os": "OS", "pnode": "Primary_node",
      "snodes": "Secondary_Nodes", "admin_state": "Autostart",
      "oper_state": "Running",
      "oper_ram": "Memory", "disk_template": "Disk_template",
      "ip": "IP_address", "mac": "MAC_address",
      "nic_mode": "NIC_Mode", "nic_link": "NIC_Link",
      "bridge": "Bridge",
      "sda_size": "Disk/0", "sdb_size": "Disk/1",
      "disk_usage": "DiskUsage",
      "status": "Status", "tags": "Tags",
      "network_port": "Network_port",
      "hv/kernel_path": "Kernel_path",
      "hv/initrd_path": "Initrd_path",
      "hv/boot_order": "HVM_boot_order",
      "hv/acpi": "HVM_ACPI",
      "hv/pae": "HVM_PAE",
      "hv/cdrom_image_path": "HVM_CDROM_image_path",
      "hv/nic_type": "HVM_NIC_type",
      "hv/disk_type": "HVM_Disk_type",
      "hv/vnc_bind_address": "VNC_bind_address",
      "serial_no": "SerialNo", "hypervisor": "Hypervisor",
      "hvparams": "Hypervisor_parameters",
      "be/memory": "Configured_memory",
      "be/vcpus": "VCPUs",
      "vcpus": "VCPUs",
      "be/auto_balance": "Auto_balance",
      "disk.count": "Disks", "disk.sizes": "Disk_sizes",
      "nic.count": "NICs", "nic.ips": "NIC_IPs",
      "nic.modes": "NIC_modes", "nic.links": "NIC_links",
      "nic.bridges": "NIC_bridges", "nic.macs": "NIC_MACs",
      "ctime": "CTime", "mtime": "MTime",
      }
  else:
    headers = None

  unitfields = ["be/memory", "oper_ram", "sd(a|b)_size", "disk\.size/.*"]
  numfields = ["be/memory", "oper_ram", "sd(a|b)_size", "be/vcpus",
               "serial_no", "(disk|nic)\.count", "disk\.size/.*"]

  list_type_fields = ("tags", "disk.sizes", "nic.macs", "nic.ips",
                      "nic.modes", "nic.links", "nic.bridges")
  # change raw values to nicer strings
  for row in output:
    for idx, field in enumerate(selected_fields):
      val = row[idx]
      if field == "snodes":
        val = ",".join(val) or "-"
      elif field == "admin_state":
        if val:
          val = "yes"
        else:
          val = "no"
      elif field == "oper_state":
        if val is None:
          val = "(node down)"
        elif val: # True
          val = "running"
        else:
          val = "stopped"
      elif field == "oper_ram":
        if val is None:
          val = "(node down)"
      elif field == "sda_size" or field == "sdb_size":
        if val is None:
          val = "N/A"
      elif field == "ctime" or field == "mtime":
        val = utils.FormatTime(val)
      elif field in list_type_fields:
        val = ",".join(str(item) for item in val)
      elif val is None:
        val = "-"
      row[idx] = str(val)

  data = GenerateTable(separator=opts.separator, headers=headers,
                       fields=selected_fields, unitfields=unitfields,
                       numfields=numfields, data=output, units=opts.units)

  for line in data:
    ToStdout(line)

  return 0


def AddInstance(opts, args):
  """Add an instance to the cluster.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the new instance name
  @rtype: int
  @return: the desired exit code

  """
  instance = args[0]

  (pnode, snode) = SplitNodeOption(opts.node)

  hypervisor = None
  hvparams = {}
  if opts.hypervisor:
    hypervisor, hvparams = opts.hypervisor

  if opts.nics:
    try:
      nic_max = max(int(nidx[0])+1 for nidx in opts.nics)
    except ValueError, err:
      raise errors.OpPrereqError("Invalid NIC index passed: %s" % str(err))
    nics = [{}] * nic_max
    for nidx, ndict in opts.nics:
      nidx = int(nidx)
      if not isinstance(ndict, dict):
        msg = "Invalid nic/%d value: expected dict, got %s" % (nidx, ndict)
        raise errors.OpPrereqError(msg)
      nics[nidx] = ndict
  elif opts.no_nics:
    # no nics
    nics = []
  else:
    # default of one nic, all auto
    nics = [{}]

  if opts.disk_template == constants.DT_DISKLESS:
    if opts.disks or opts.sd_size is not None:
      raise errors.OpPrereqError("Diskless instance but disk"
                                 " information passed")
    disks = []
  else:
    if not opts.disks and not opts.sd_size:
      raise errors.OpPrereqError("No disk information specified")
    if opts.disks and opts.sd_size is not None:
      raise errors.OpPrereqError("Please use either the '--disk' or"
                                 " '-s' option")
    if opts.sd_size is not None:
      opts.disks = [(0, {"size": opts.sd_size})]
    try:
      disk_max = max(int(didx[0])+1 for didx in opts.disks)
    except ValueError, err:
      raise errors.OpPrereqError("Invalid disk index passed: %s" % str(err))
    disks = [{}] * disk_max
    for didx, ddict in opts.disks:
      didx = int(didx)
      if not isinstance(ddict, dict):
        msg = "Invalid disk/%d value: expected dict, got %s" % (didx, ddict)
        raise errors.OpPrereqError(msg)
      elif "size" not in ddict:
        raise errors.OpPrereqError("Missing size for disk %d" % didx)
      try:
        ddict["size"] = utils.ParseUnit(ddict["size"])
      except ValueError, err:
        raise errors.OpPrereqError("Invalid disk size for disk %d: %s" %
                                   (didx, err))
      disks[didx] = ddict

  utils.ForceDictType(opts.beparams, constants.BES_PARAMETER_TYPES)
  utils.ForceDictType(hvparams, constants.HVS_PARAMETER_TYPES)

  op = opcodes.OpCreateInstance(instance_name=instance,
                                disks=disks,
                                disk_template=opts.disk_template,
                                nics=nics,
                                mode=constants.INSTANCE_CREATE,
                                os_type=opts.os, pnode=pnode,
                                snode=snode,
                                start=opts.start, ip_check=opts.ip_check,
                                wait_for_sync=opts.wait_for_sync,
                                hypervisor=hypervisor,
                                hvparams=hvparams,
                                beparams=opts.beparams,
                                iallocator=opts.iallocator,
                                file_storage_dir=opts.file_storage_dir,
                                file_driver=opts.file_driver,
                                )

  SubmitOrSend(op, opts)
  return 0


def BatchCreate(opts, args):
  """Create instances using a definition file.

  This function reads a json file with instances defined
  in the form::

    {"instance-name":{
      "disk_size": [20480],
      "template": "drbd",
      "backend": {
        "memory": 512,
        "vcpus": 1 },
      "os": "debootstrap",
      "primary_node": "firstnode",
      "secondary_node": "secondnode",
      "iallocator": "dumb"}
    }

  Note that I{primary_node} and I{secondary_node} have precedence over
  I{iallocator}.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain one element, the json filename
  @rtype: int
  @return: the desired exit code

  """
  _DEFAULT_SPECS = {"disk_size": [20 * 1024],
                    "backend": {},
                    "iallocator": None,
                    "primary_node": None,
                    "secondary_node": None,
                    "nics": None,
                    "start": True,
                    "ip_check": True,
                    "hypervisor": None,
                    "hvparams": {},
                    "file_storage_dir": None,
                    "file_driver": 'loop'}

  def _PopulateWithDefaults(spec):
    """Returns a new hash combined with default values."""
    mydict = _DEFAULT_SPECS.copy()
    mydict.update(spec)
    return mydict

  def _Validate(spec):
    """Validate the instance specs."""
    # Validate fields required under any circumstances
    for required_field in ('os', 'template'):
      if required_field not in spec:
        raise errors.OpPrereqError('Required field "%s" is missing.' %
                                   required_field)
    # Validate special fields
    if spec['primary_node'] is not None:
      if (spec['template'] in constants.DTS_NET_MIRROR and
          spec['secondary_node'] is None):
        raise errors.OpPrereqError('Template requires secondary node, but'
                                   ' there was no secondary provided.')
    elif spec['iallocator'] is None:
      raise errors.OpPrereqError('You have to provide at least a primary_node'
                                 ' or an iallocator.')

    if (spec['hvparams'] and
        not isinstance(spec['hvparams'], dict)):
      raise errors.OpPrereqError('Hypervisor parameters must be a dict.')

  json_filename = args[0]
  try:
    fd = open(json_filename, 'r')
    instance_data = simplejson.load(fd)
    fd.close()
  except Exception, err:
    ToStderr("Can't parse the instance definition file: %s" % str(err))
    return 1

  jex = JobExecutor()

  # Iterate over the instances and do:
  #  * Populate the specs with default value
  #  * Validate the instance specs
  i_names = utils.NiceSort(instance_data.keys())
  for name in i_names:
    specs = instance_data[name]
    specs = _PopulateWithDefaults(specs)
    _Validate(specs)

    hypervisor = specs['hypervisor']
    hvparams = specs['hvparams']

    disks = []
    for elem in specs['disk_size']:
      try:
        size = utils.ParseUnit(elem)
      except ValueError, err:
        raise errors.OpPrereqError("Invalid disk size '%s' for"
                                   " instance %s: %s" %
                                   (elem, name, err))
      disks.append({"size": size})

    utils.ForceDictType(specs['backend'], constants.BES_PARAMETER_TYPES)
    utils.ForceDictType(hvparams, constants.HVS_PARAMETER_TYPES)

    tmp_nics = []
    for field in ('ip', 'mac', 'mode', 'link', 'bridge'):
      if field in specs:
        if not tmp_nics:
          tmp_nics.append({})
        tmp_nics[0][field] = specs[field]

    if specs['nics'] is not None and tmp_nics:
      raise errors.OpPrereqError("'nics' list incompatible with using"
                                 " individual nic fields as well")
    elif specs['nics'] is not None:
      tmp_nics = specs['nics']
    elif not tmp_nics:
      tmp_nics = [{}]

    op = opcodes.OpCreateInstance(instance_name=name,
                                  disks=disks,
                                  disk_template=specs['template'],
                                  mode=constants.INSTANCE_CREATE,
                                  os_type=specs['os'],
                                  pnode=specs['primary_node'],
                                  snode=specs['secondary_node'],
                                  nics=tmp_nics,
                                  start=specs['start'],
                                  ip_check=specs['ip_check'],
                                  wait_for_sync=True,
                                  iallocator=specs['iallocator'],
                                  hypervisor=hypervisor,
                                  hvparams=hvparams,
                                  beparams=specs['backend'],
                                  file_storage_dir=specs['file_storage_dir'],
                                  file_driver=specs['file_driver'])

    jex.QueueJob(name, op)
  # we never want to wait, just show the submitted job IDs
  jex.WaitOrShow(False)

  return 0


def ReinstallInstance(opts, args):
  """Reinstall an instance.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the name of the
      instance to be reinstalled
  @rtype: int
  @return: the desired exit code

  """
  # first, compute the desired name list
  if opts.multi_mode is None:
    opts.multi_mode = _SHUTDOWN_INSTANCES

  inames = _ExpandMultiNames(opts.multi_mode, args)
  if not inames:
    raise errors.OpPrereqError("Selection filter does not match any instances")

  # second, if requested, ask for an OS
  if opts.select_os is True:
    op = opcodes.OpDiagnoseOS(output_fields=["name", "valid"], names=[])
    result = SubmitOpCode(op)

    if not result:
      ToStdout("Can't get the OS list")
      return 1

    ToStdout("Available OS templates:")
    number = 0
    choices = []
    for entry in result:
      ToStdout("%3s: %s", number, entry[0])
      choices.append(("%s" % number, entry[0], entry[0]))
      number = number + 1

    choices.append(('x', 'exit', 'Exit gnt-instance reinstall'))
    selected = AskUser("Enter OS template number (or x to abort):",
                       choices)

    if selected == 'exit':
      ToStderr("User aborted reinstall, exiting")
      return 1

    os_name = selected
  else:
    os_name = opts.os

  # third, get confirmation: multi-reinstall requires --force-multi
  # *and* --force, single-reinstall just --force
  multi_on = opts.multi_mode != _SHUTDOWN_INSTANCES or len(inames) > 1
  if multi_on:
    warn_msg = "Note: this will remove *all* data for the below instances!\n"
    if not ((opts.force_multi and opts.force) or
            _ConfirmOperation(inames, "reinstall", extra=warn_msg)):
      return 1
  else:
    if not opts.force:
      usertext = ("This will reinstall the instance %s and remove"
                  " all data. Continue?") % inames[0]
      if not AskUser(usertext):
        return 1

  jex = JobExecutor(verbose=multi_on)
  for instance_name in inames:
    op = opcodes.OpReinstallInstance(instance_name=instance_name,
                                     os_type=os_name)
    jex.QueueJob(instance_name, op)

  jex.WaitOrShow(not opts.submit_only)
  return 0


def RemoveInstance(opts, args):
  """Remove an instance.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the name of
      the instance to be removed
  @rtype: int
  @return: the desired exit code

  """
  instance_name = args[0]
  force = opts.force
  cl = GetClient()

  if not force:
    _EnsureInstancesExist(cl, [instance_name])

    usertext = ("This will remove the volumes of the instance %s"
                " (including mirrors), thus removing all the data"
                " of the instance. Continue?") % instance_name
    if not AskUser(usertext):
      return 1

  op = opcodes.OpRemoveInstance(instance_name=instance_name,
                                ignore_failures=opts.ignore_failures)
  SubmitOrSend(op, opts, cl=cl)
  return 0


def RenameInstance(opts, args):
  """Rename an instance.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain two elements, the old and the
      new instance names
  @rtype: int
  @return: the desired exit code

  """
  op = opcodes.OpRenameInstance(instance_name=args[0],
                                new_name=args[1],
                                ignore_ip=opts.ignore_ip)
  SubmitOrSend(op, opts)
  return 0


def ActivateDisks(opts, args):
  """Activate an instance's disks.

  This serves two purposes:
    - it allows (as long as the instance is not running)
      mounting the disks and modifying them from the node
    - it repairs inactive secondary drbds

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  instance_name = args[0]
  op = opcodes.OpActivateInstanceDisks(instance_name=instance_name,
                                       ignore_size=opts.ignore_size)
  disks_info = SubmitOrSend(op, opts)
  for host, iname, nname in disks_info:
    ToStdout("%s:%s:%s", host, iname, nname)
  return 0


def DeactivateDisks(opts, args):
  """Deactivate an instance's disks.

  This function takes the instance name, looks for its primary node
  and the tries to shutdown its block devices on that node.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  instance_name = args[0]
  op = opcodes.OpDeactivateInstanceDisks(instance_name=instance_name)
  SubmitOrSend(op, opts)
  return 0


def RecreateDisks(opts, args):
  """Recreate an instance's disks.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  instance_name = args[0]
  if opts.disks:
    try:
      opts.disks = [int(v) for v in opts.disks.split(",")]
    except (ValueError, TypeError), err:
      ToStderr("Invalid disks value: %s" % str(err))
      return 1
  else:
    opts.disks = []

  op = opcodes.OpRecreateInstanceDisks(instance_name=instance_name,
                                       disks=opts.disks)
  SubmitOrSend(op, opts)
  return 0


def GrowDisk(opts, args):
  """Grow an instance's disks.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain two elements, the instance name
      whose disks we grow and the disk name, e.g. I{sda}
  @rtype: int
  @return: the desired exit code

  """
  instance = args[0]
  disk = args[1]
  try:
    disk = int(disk)
  except ValueError, err:
    raise errors.OpPrereqError("Invalid disk index: %s" % str(err))
  amount = utils.ParseUnit(args[2])
  op = opcodes.OpGrowDisk(instance_name=instance, disk=disk, amount=amount,
                          wait_for_sync=opts.wait_for_sync)
  SubmitOrSend(op, opts)
  return 0


def StartupInstance(opts, args):
  """Startup instances.

  Depending on the options given, this will start one or more
  instances.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: the instance or node names based on which we
      create the final selection (in conjunction with the
      opts argument)
  @rtype: int
  @return: the desired exit code

  """
  cl = GetClient()
  if opts.multi_mode is None:
    opts.multi_mode = _SHUTDOWN_INSTANCES
  inames = _ExpandMultiNames(opts.multi_mode, args, client=cl)
  if not inames:
    raise errors.OpPrereqError("Selection filter does not match any instances")
  multi_on = opts.multi_mode != _SHUTDOWN_INSTANCES or len(inames) > 1
  if not (opts.force_multi or not multi_on
          or _ConfirmOperation(inames, "startup")):
    return 1
  jex = cli.JobExecutor(verbose=multi_on, cl=cl)
  for name in inames:
    op = opcodes.OpStartupInstance(instance_name=name,
                                   force=opts.force)
    # do not add these parameters to the opcode unless they're defined
    if opts.hvparams:
      op.hvparams = opts.hvparams
    if opts.beparams:
      op.beparams = opts.beparams
    jex.QueueJob(name, op)
  jex.WaitOrShow(not opts.submit_only)
  return 0


def RebootInstance(opts, args):
  """Reboot instance(s).

  Depending on the parameters given, this will reboot one or more
  instances.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: the instance or node names based on which we
      create the final selection (in conjunction with the
      opts argument)
  @rtype: int
  @return: the desired exit code

  """
  cl = GetClient()
  if opts.multi_mode is None:
    opts.multi_mode = _SHUTDOWN_INSTANCES
  inames = _ExpandMultiNames(opts.multi_mode, args, client=cl)
  if not inames:
    raise errors.OpPrereqError("Selection filter does not match any instances")
  multi_on = opts.multi_mode != _SHUTDOWN_INSTANCES or len(inames) > 1
  if not (opts.force_multi or not multi_on
          or _ConfirmOperation(inames, "reboot")):
    return 1
  jex = JobExecutor(verbose=multi_on, cl=cl)
  for name in inames:
    op = opcodes.OpRebootInstance(instance_name=name,
                                  reboot_type=opts.reboot_type,
                                  ignore_secondaries=opts.ignore_secondaries)
    jex.QueueJob(name, op)
  jex.WaitOrShow(not opts.submit_only)
  return 0


def ShutdownInstance(opts, args):
  """Shutdown an instance.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: the instance or node names based on which we
      create the final selection (in conjunction with the
      opts argument)
  @rtype: int
  @return: the desired exit code

  """
  cl = GetClient()
  if opts.multi_mode is None:
    opts.multi_mode = _SHUTDOWN_INSTANCES
  inames = _ExpandMultiNames(opts.multi_mode, args, client=cl)
  if not inames:
    raise errors.OpPrereqError("Selection filter does not match any instances")
  multi_on = opts.multi_mode != _SHUTDOWN_INSTANCES or len(inames) > 1
  if not (opts.force_multi or not multi_on
          or _ConfirmOperation(inames, "shutdown")):
    return 1

  jex = cli.JobExecutor(verbose=multi_on, cl=cl)
  for name in inames:
    op = opcodes.OpShutdownInstance(instance_name=name)
    jex.QueueJob(name, op)
  jex.WaitOrShow(not opts.submit_only)
  return 0


def ReplaceDisks(opts, args):
  """Replace the disks of an instance

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  instance_name = args[0]
  new_2ndary = opts.new_secondary
  iallocator = opts.iallocator
  if opts.disks is None:
    disks = []
  else:
    try:
      disks = [int(i) for i in opts.disks.split(",")]
    except ValueError, err:
      raise errors.OpPrereqError("Invalid disk index passed: %s" % str(err))
  cnt = [opts.on_primary, opts.on_secondary, opts.auto,
         new_2ndary is not None, iallocator is not None].count(True)
  if cnt != 1:
    raise errors.OpPrereqError("One and only one of the -p, -s, -a, -n and -i"
                               " options must be passed")
  elif opts.on_primary:
    mode = constants.REPLACE_DISK_PRI
  elif opts.on_secondary:
    mode = constants.REPLACE_DISK_SEC
  elif opts.auto:
    mode = constants.REPLACE_DISK_AUTO
    if disks:
      raise errors.OpPrereqError("Cannot specify disks when using automatic"
                                 " mode")
  elif new_2ndary is not None or iallocator is not None:
    # replace secondary
    mode = constants.REPLACE_DISK_CHG

  op = opcodes.OpReplaceDisks(instance_name=args[0], disks=disks,
                              remote_node=new_2ndary, mode=mode,
                              iallocator=iallocator)
  SubmitOrSend(op, opts)
  return 0


def FailoverInstance(opts, args):
  """Failover an instance.

  The failover is done by shutting it down on its present node and
  starting it on the secondary.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  cl = GetClient()
  instance_name = args[0]
  force = opts.force

  if not force:
    _EnsureInstancesExist(cl, [instance_name])

    usertext = ("Failover will happen to image %s."
                " This requires a shutdown of the instance. Continue?" %
                (instance_name,))
    if not AskUser(usertext):
      return 1

  op = opcodes.OpFailoverInstance(instance_name=instance_name,
                                  ignore_consistency=opts.ignore_consistency)
  SubmitOrSend(op, opts, cl=cl)
  return 0


def MigrateInstance(opts, args):
  """Migrate an instance.

  The migrate is done without shutdown.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  cl = GetClient()
  instance_name = args[0]
  force = opts.force

  if not force:
    _EnsureInstancesExist(cl, [instance_name])

    if opts.cleanup:
      usertext = ("Instance %s will be recovered from a failed migration."
                  " Note that the migration procedure (including cleanup)" %
                  (instance_name,))
    else:
      usertext = ("Instance %s will be migrated. Note that migration" %
                  (instance_name,))
    usertext += (" is **experimental** in this version."
                " This might impact the instance if anything goes wrong."
                " Continue?")
    if not AskUser(usertext):
      return 1

  op = opcodes.OpMigrateInstance(instance_name=instance_name, live=opts.live,
                                 cleanup=opts.cleanup)
  SubmitOpCode(op, cl=cl)
  return 0


def MoveInstance(opts, args):
  """Move an instance.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  cl = GetClient()
  instance_name = args[0]
  force = opts.force

  if not force:
    usertext = ("Instance %s will be moved."
                " This requires a shutdown of the instance. Continue?" %
                (instance_name,))
    if not AskUser(usertext):
      return 1

  op = opcodes.OpMoveInstance(instance_name=instance_name,
                              target_node=opts.target_node)
  SubmitOrSend(op, opts, cl=cl)
  return 0


def ConnectToInstanceConsole(opts, args):
  """Connect to the console of an instance.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: should contain only one element, the instance name
  @rtype: int
  @return: the desired exit code

  """
  instance_name = args[0]

  op = opcodes.OpConnectConsole(instance_name=instance_name)
  cmd = SubmitOpCode(op)

  if opts.show_command:
    ToStdout("%s", utils.ShellQuoteArgs(cmd))
  else:
    try:
      os.execvp(cmd[0], cmd)
    finally:
      ToStderr("Can't run console command %s with arguments:\n'%s'",
               cmd[0], " ".join(cmd))
      os._exit(1)


def _FormatLogicalID(dev_type, logical_id):
  """Formats the logical_id of a disk.

  """
  if dev_type == constants.LD_DRBD8:
    node_a, node_b, port, minor_a, minor_b, key = logical_id
    data = [
      ("nodeA", "%s, minor=%s" % (node_a, minor_a)),
      ("nodeB", "%s, minor=%s" % (node_b, minor_b)),
      ("port", port),
      ("auth key", key),
      ]
  elif dev_type == constants.LD_LV:
    vg_name, lv_name = logical_id
    data = ["%s/%s" % (vg_name, lv_name)]
  else:
    data = [str(logical_id)]

  return data


def _FormatBlockDevInfo(idx, top_level, dev, static):
  """Show block device information.

  This is only used by L{ShowInstanceConfig}, but it's too big to be
  left for an inline definition.

  @type idx: int
  @param idx: the index of the current disk
  @type top_level: boolean
  @param top_level: if this a top-level disk?
  @type dev: dict
  @param dev: dictionary with disk information
  @type static: boolean
  @param static: wheter the device information doesn't contain
      runtime information but only static data
  @return: a list of either strings, tuples or lists
      (which should be formatted at a higher indent level)

  """
  def helper(dtype, status):
    """Format one line for physical device status.

    @type dtype: str
    @param dtype: a constant from the L{constants.LDS_BLOCK} set
    @type status: tuple
    @param status: a tuple as returned from L{backend.FindBlockDevice}
    @return: the string representing the status

    """
    if not status:
      return "not active"
    txt = ""
    (path, major, minor, syncp, estt, degr, ldisk_status) = status
    if major is None:
      major_string = "N/A"
    else:
      major_string = str(major)

    if minor is None:
      minor_string = "N/A"
    else:
      minor_string = str(minor)

    txt += ("%s (%s:%s)" % (path, major_string, minor_string))
    if dtype in (constants.LD_DRBD8, ):
      if syncp is not None:
        sync_text = "*RECOVERING* %5.2f%%," % syncp
        if estt:
          sync_text += " ETA %ds" % estt
        else:
          sync_text += " ETA unknown"
      else:
        sync_text = "in sync"
      if degr:
        degr_text = "*DEGRADED*"
      else:
        degr_text = "ok"
      if ldisk_status == constants.LDS_FAULTY:
        ldisk_text = " *MISSING DISK*"
      elif ldisk_status == constants.LDS_UNKNOWN:
        ldisk_text = " *UNCERTAIN STATE*"
      else:
        ldisk_text = ""
      txt += (" %s, status %s%s" % (sync_text, degr_text, ldisk_text))
    elif dtype == constants.LD_LV:
      if ldisk_status == constants.LDS_FAULTY:
        ldisk_text = " *FAILED* (failed drive?)"
      else:
        ldisk_text = ""
      txt += ldisk_text
    return txt

  # the header
  if top_level:
    if dev["iv_name"] is not None:
      txt = dev["iv_name"]
    else:
      txt = "disk %d" % idx
  else:
    txt = "child %d" % idx
  if isinstance(dev["size"], int):
    nice_size = utils.FormatUnit(dev["size"], "h")
  else:
    nice_size = dev["size"]
  d1 = ["- %s: %s, size %s" % (txt, dev["dev_type"], nice_size)]
  data = []
  if top_level:
    data.append(("access mode", dev["mode"]))
  if dev["logical_id"] is not None:
    try:
      l_id = _FormatLogicalID(dev["dev_type"], dev["logical_id"])
    except ValueError:
      l_id = [str(dev["logical_id"])]
    if len(l_id) == 1:
      data.append(("logical_id", l_id[0]))
    else:
      data.extend(l_id)
  elif dev["physical_id"] is not None:
    data.append("physical_id:")
    data.append([dev["physical_id"]])
  if not static:
    data.append(("on primary", helper(dev["dev_type"], dev["pstatus"])))
  if dev["sstatus"] and not static:
    data.append(("on secondary", helper(dev["dev_type"], dev["sstatus"])))

  if dev["children"]:
    data.append("child devices:")
    for c_idx, child in enumerate(dev["children"]):
      data.append(_FormatBlockDevInfo(c_idx, False, child, static))
  d1.append(data)
  return d1


def _FormatList(buf, data, indent_level):
  """Formats a list of data at a given indent level.

  If the element of the list is:
    - a string, it is simply formatted as is
    - a tuple, it will be split into key, value and the all the
      values in a list will be aligned all at the same start column
    - a list, will be recursively formatted

  @type buf: StringIO
  @param buf: the buffer into which we write the output
  @param data: the list to format
  @type indent_level: int
  @param indent_level: the indent level to format at

  """
  max_tlen = max([len(elem[0]) for elem in data
                 if isinstance(elem, tuple)] or [0])
  for elem in data:
    if isinstance(elem, basestring):
      buf.write("%*s%s\n" % (2*indent_level, "", elem))
    elif isinstance(elem, tuple):
      key, value = elem
      spacer = "%*s" % (max_tlen - len(key), "")
      buf.write("%*s%s:%s %s\n" % (2*indent_level, "", key, spacer, value))
    elif isinstance(elem, list):
      _FormatList(buf, elem, indent_level+1)


def ShowInstanceConfig(opts, args):
  """Compute instance run-time status.

  @param opts: the command line options selected by the user
  @type args: list
  @param args: either an empty list, and then we query all
      instances, or should contain a list of instance names
  @rtype: int
  @return: the desired exit code

  """