Synnefo » snf-ganeti » ganeti-local

#!/usr/bin/python

#

# Copyright (C) 2011, 2013 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.

"""Script for testing ganeti.hypervisor.hv_lxc"""

import string # pylint: disable=W0402

import unittest

import tempfile

import shutil

import random

import os

from ganeti import constants

from ganeti import objects

from ganeti import pathutils

from ganeti import hypervisor

from ganeti import utils

from ganeti import errors

from ganeti import compat

from ganeti.hypervisor import hv_xen

import testutils

# Map from hypervisor class to hypervisor name

HVCLASS_TO_HVNAME = utils.InvertDict(hypervisor._HYPERVISOR_MAP)

class TestConsole(unittest.TestCase):

  def test(self):

    for cls in [hv_xen.XenPvmHypervisor, hv_xen.XenHvmHypervisor]:

      instance = objects.Instance(name="xen.example.com",

                                  primary_node="node24828")

      cons = cls.GetInstanceConsole(instance, {}, {})

      self.assertTrue(cons.Validate())

      self.assertEqual(cons.kind, constants.CONS_SSH)

      self.assertEqual(cons.host, instance.primary_node)

      self.assertEqual(cons.command[-1], instance.name)

class TestCreateConfigCpus(unittest.TestCase):

  def testEmpty(self):

    for cpu_mask in [None, ""]:

      self.assertEqual(hv_xen._CreateConfigCpus(cpu_mask),

                       "cpus = [  ]")

  def testAll(self):

    self.assertEqual(hv_xen._CreateConfigCpus(constants.CPU_PINNING_ALL),

                     None)

  def testOne(self):

    self.assertEqual(hv_xen._CreateConfigCpus("9"), "cpu = \"9\"")

  def testMultiple(self):

    self.assertEqual(hv_xen._CreateConfigCpus("0-2,4,5-5:3:all"),

                     ("cpus = [ \"0,1,2,4,5\", \"3\", \"%s\" ]" %

                      constants.CPU_PINNING_ALL_XEN))

class TestParseXmList(testutils.GanetiTestCase):

  def test(self):

    data = testutils.ReadTestData("xen-xm-list-4.0.1-dom0-only.txt")

    # Exclude node

    self.assertEqual(hv_xen._ParseXmList(data.splitlines(), False), [])

    # Include node

    result = hv_xen._ParseXmList(data.splitlines(), True)

    self.assertEqual(len(result), 1)

    self.assertEqual(len(result[0]), 6)

    # Name

    self.assertEqual(result[0][0], hv_xen._DOM0_NAME)

    # ID

    self.assertEqual(result[0][1], 0)

    # Memory

    self.assertEqual(result[0][2], 1023)

    # VCPUs

    self.assertEqual(result[0][3], 1)

    # State

    self.assertEqual(result[0][4], "r-----")

    # Time

    self.assertAlmostEqual(result[0][5], 121152.6)

  def testWrongLineFormat(self):

    tests = [

      ["three fields only"],

      ["name InvalidID 128 1 r----- 12345"],

      ]

    for lines in tests:

      try:

        hv_xen._ParseXmList(["Header would be here"] + lines, False)

      except errors.HypervisorError, err:

        self.assertTrue("Can't parse output of xm list" in str(err))

      else:

        self.fail("Exception was not raised")

class TestGetXmList(testutils.GanetiTestCase):

  def _Fail(self):

    return utils.RunResult(constants.EXIT_FAILURE, None,

                           "stdout", "stderr", None,

                           NotImplemented, NotImplemented)

  def testTimeout(self):

    fn = testutils.CallCounter(self._Fail)

    try:

      hv_xen._GetXmList(fn, False, _timeout=0.1)

    except errors.HypervisorError, err:

      self.assertTrue("timeout exceeded" in str(err))

    else:

      self.fail("Exception was not raised")

    self.assertTrue(fn.Count() < 10,

                    msg="'xm list' was called too many times")

  def _Success(self, stdout):

    return utils.RunResult(constants.EXIT_SUCCESS, None, stdout, "", None,

                           NotImplemented, NotImplemented)

  def testSuccess(self):

    data = testutils.ReadTestData("xen-xm-list-4.0.1-four-instances.txt")

    fn = testutils.CallCounter(compat.partial(self._Success, data))

    result = hv_xen._GetXmList(fn, True, _timeout=0.1)

    self.assertEqual(len(result), 4)

    self.assertEqual(map(compat.fst, result), [

      "Domain-0",

      "server01.example.com",

      "web3106215069.example.com",

      "testinstance.example.com",

      ])

    self.assertEqual(fn.Count(), 1)

class TestParseNodeInfo(testutils.GanetiTestCase):

  def testEmpty(self):

    self.assertEqual(hv_xen._ParseNodeInfo(""), {})

  def testUnknownInput(self):

    data = "\n".join([

      "foo bar",

      "something else goes",

      "here",

      ])

    self.assertEqual(hv_xen._ParseNodeInfo(data), {})

  def testBasicInfo(self):

    data = testutils.ReadTestData("xen-xm-info-4.0.1.txt")

    result = hv_xen._ParseNodeInfo(data)

    self.assertEqual(result, {

      "cpu_nodes": 1,

      "cpu_sockets": 2,

      "cpu_total": 4,

      "hv_version": (4, 0),

      "memory_free": 8004,

      "memory_total": 16378,

      })

class TestMergeInstanceInfo(testutils.GanetiTestCase):

  def testEmpty(self):

    self.assertEqual(hv_xen._MergeInstanceInfo({}, lambda _: []), {})

  def _FakeXmList(self, include_node):

    self.assertTrue(include_node)

    return [

      (hv_xen._DOM0_NAME, NotImplemented, 4096, 7, NotImplemented,

       NotImplemented),

      ("inst1.example.com", NotImplemented, 2048, 4, NotImplemented,

       NotImplemented),

      ]

  def testMissingNodeInfo(self):

    result = hv_xen._MergeInstanceInfo({}, self._FakeXmList)

    self.assertEqual(result, {

      "memory_dom0": 4096,

      "dom0_cpus": 7,

      })

  def testWithNodeInfo(self):

    info = testutils.ReadTestData("xen-xm-info-4.0.1.txt")

    result = hv_xen._GetNodeInfo(info, self._FakeXmList)

    self.assertEqual(result, {

      "cpu_nodes": 1,

      "cpu_sockets": 2,

      "cpu_total": 4,

      "dom0_cpus": 7,

      "hv_version": (4, 0),

      "memory_dom0": 4096,

      "memory_free": 8004,

      "memory_hv": 2230,

      "memory_total": 16378,

      })

class TestGetConfigFileDiskData(unittest.TestCase):

  def testLetterCount(self):

    self.assertEqual(len(hv_xen._DISK_LETTERS), 26)

  def testNoDisks(self):

    self.assertEqual(hv_xen._GetConfigFileDiskData([], "hd"), [])

  def testManyDisks(self):

    for offset in [0, 1, 10]:

      disks = [(objects.Disk(dev_type=constants.LD_LV), "/tmp/disk/%s" % idx)

               for idx in range(len(hv_xen._DISK_LETTERS) + offset)]

      if offset == 0:

        result = hv_xen._GetConfigFileDiskData(disks, "hd")

        self.assertEqual(result, [

          "'phy:/tmp/disk/%s,hd%s,r'" % (idx, string.ascii_lowercase[idx])

          for idx in range(len(hv_xen._DISK_LETTERS) + offset)

          ])

      else:

        try:

          hv_xen._GetConfigFileDiskData(disks, "hd")

        except errors.HypervisorError, err:

          self.assertEqual(str(err), "Too many disks")

        else:

          self.fail("Exception was not raised")

  def testTwoLvDisksWithMode(self):

    disks = [

      (objects.Disk(dev_type=constants.LD_LV, mode=constants.DISK_RDWR),

       "/tmp/diskFirst"),

      (objects.Disk(dev_type=constants.LD_LV, mode=constants.DISK_RDONLY),

       "/tmp/diskLast"),

      ]

    result = hv_xen._GetConfigFileDiskData(disks, "hd")

    self.assertEqual(result, [

      "'phy:/tmp/diskFirst,hda,w'",

      "'phy:/tmp/diskLast,hdb,r'",

      ])

  def testFileDisks(self):

    disks = [

      (objects.Disk(dev_type=constants.LD_FILE, mode=constants.DISK_RDWR,

                    physical_id=[constants.FD_LOOP]),

       "/tmp/diskFirst"),

      (objects.Disk(dev_type=constants.LD_FILE, mode=constants.DISK_RDONLY,

                    physical_id=[constants.FD_BLKTAP]),

       "/tmp/diskTwo"),

      (objects.Disk(dev_type=constants.LD_FILE, mode=constants.DISK_RDWR,

                    physical_id=[constants.FD_LOOP]),

       "/tmp/diskThree"),

      (objects.Disk(dev_type=constants.LD_FILE, mode=constants.DISK_RDWR,

                    physical_id=[constants.FD_BLKTAP]),

       "/tmp/diskLast"),

      ]

    result = hv_xen._GetConfigFileDiskData(disks, "sd")

    self.assertEqual(result, [

      "'file:/tmp/diskFirst,sda,w'",

      "'tap:aio:/tmp/diskTwo,sdb,r'",

      "'file:/tmp/diskThree,sdc,w'",

      "'tap:aio:/tmp/diskLast,sdd,w'",

      ])

  def testInvalidFileDisk(self):

    disks = [

      (objects.Disk(dev_type=constants.LD_FILE, mode=constants.DISK_RDWR,

                    physical_id=["#unknown#"]),

       "/tmp/diskinvalid"),

      ]

    self.assertRaises(KeyError, hv_xen._GetConfigFileDiskData, disks, "sd")

class TestXenHypervisorUnknownCommand(unittest.TestCase):

  def test(self):

    cmd = "#unknown command#"

    self.assertFalse(cmd in constants.KNOWN_XEN_COMMANDS)

    hv = hv_xen.XenHypervisor(_cfgdir=NotImplemented,

                              _run_cmd_fn=NotImplemented,

                              _cmd=cmd)

    self.assertRaises(errors.ProgrammerError, hv._RunXen, [])

class TestXenHypervisorWriteConfigFile(unittest.TestCase):

  def setUp(self):

    self.tmpdir = tempfile.mkdtemp()

  def tearDown(self):

    shutil.rmtree(self.tmpdir)

  def testWriteError(self):

    cfgdir = utils.PathJoin(self.tmpdir, "foobar")

    hv = hv_xen.XenHypervisor(_cfgdir=cfgdir,

                              _run_cmd_fn=NotImplemented,

                              _cmd=NotImplemented)

    self.assertFalse(os.path.exists(cfgdir))

    try:

      hv._WriteConfigFile("name", "data")

    except errors.HypervisorError, err:

      self.assertTrue(str(err).startswith("Cannot write Xen instance"))

    else:

      self.fail("Exception was not raised")

class _TestXenHypervisor(object):

  TARGET = NotImplemented

  CMD = NotImplemented

  HVNAME = NotImplemented

  def setUp(self):

    super(_TestXenHypervisor, self).setUp()

    self.tmpdir = tempfile.mkdtemp()

    self.vncpw = "".join(random.sample(string.ascii_letters, 10))

    self.vncpw_path = utils.PathJoin(self.tmpdir, "vncpw")

    utils.WriteFile(self.vncpw_path, data=self.vncpw)

  def tearDown(self):

    super(_TestXenHypervisor, self).tearDown()

    shutil.rmtree(self.tmpdir)

  def _GetHv(self, run_cmd=NotImplemented):

    return self.TARGET(_cfgdir=self.tmpdir, _run_cmd_fn=run_cmd, _cmd=self.CMD)

  def _SuccessCommand(self, stdout, cmd):

    self.assertEqual(cmd[0], self.CMD)

    return utils.RunResult(constants.EXIT_SUCCESS, None, stdout, "", None,

                           NotImplemented, NotImplemented)

  def _FailingCommand(self, cmd):

    self.assertEqual(cmd[0], self.CMD)

    return utils.RunResult(constants.EXIT_FAILURE, None,

                           "", "This command failed", None,

                           NotImplemented, NotImplemented)

  def _FakeTcpPing(self, expected, result, target, port, **kwargs):

    self.assertEqual((target, port), expected)

    return result

  def testReadingNonExistentConfigFile(self):

    hv = self._GetHv()

    try:

      hv._ReadConfigFile("inst15780.example.com")

    except errors.HypervisorError, err:

      self.assertTrue(str(err).startswith("Failed to load Xen config file:"))

    else:

      self.fail("Exception was not raised")

  def testRemovingAutoConfigFile(self):

    name = "inst8206.example.com"

    cfgfile = utils.PathJoin(self.tmpdir, name)

    autodir = utils.PathJoin(self.tmpdir, "auto")

    autocfgfile = utils.PathJoin(autodir, name)

    os.mkdir(autodir)

    utils.WriteFile(autocfgfile, data="")

    hv = self._GetHv()

    self.assertTrue(os.path.isfile(autocfgfile))

    hv._WriteConfigFile(name, "content")

    self.assertFalse(os.path.exists(autocfgfile))

    self.assertEqual(utils.ReadFile(cfgfile), "content")

  def _XenList(self, cmd):

    self.assertEqual(cmd, [self.CMD, "list"])

    # TODO: Use actual data from "xl" command

    output = testutils.ReadTestData("xen-xm-list-4.0.1-four-instances.txt")

    return self._SuccessCommand(output, cmd)

  def testGetInstanceInfo(self):

    hv = self._GetHv(run_cmd=self._XenList)

    (name, instid, memory, vcpus, state, runtime) = \

      hv.GetInstanceInfo("server01.example.com")

    self.assertEqual(name, "server01.example.com")

    self.assertEqual(instid, 1)

    self.assertEqual(memory, 1024)

    self.assertEqual(vcpus, 1)

    self.assertEqual(state, "-b----")

    self.assertAlmostEqual(runtime, 167643.2)

  def testGetInstanceInfoDom0(self):

    hv = self._GetHv(run_cmd=self._XenList)

    # TODO: Not sure if this is actually used anywhere (can't find it), but the

    # code supports querying for Dom0

    (name, instid, memory, vcpus, state, runtime) = \

      hv.GetInstanceInfo(hv_xen._DOM0_NAME)

    self.assertEqual(name, "Domain-0")

    self.assertEqual(instid, 0)

    self.assertEqual(memory, 1023)

    self.assertEqual(vcpus, 1)

    self.assertEqual(state, "r-----")

    self.assertAlmostEqual(runtime, 154706.1)

  def testGetInstanceInfoUnknown(self):

    hv = self._GetHv(run_cmd=self._XenList)

    result = hv.GetInstanceInfo("unknown.example.com")

    self.assertTrue(result is None)

  def testGetAllInstancesInfo(self):

    hv = self._GetHv(run_cmd=self._XenList)

    result = hv.GetAllInstancesInfo()

    self.assertEqual(map(compat.fst, result), [

      "server01.example.com",

      "web3106215069.example.com",

      "testinstance.example.com",

      ])

  def testListInstances(self):

    hv = self._GetHv(run_cmd=self._XenList)

    self.assertEqual(hv.ListInstances(), [

      "server01.example.com",

      "web3106215069.example.com",

      "testinstance.example.com",

      ])

  def testVerify(self):

    output = testutils.ReadTestData("xen-xm-info-4.0.1.txt")

    hv = self._GetHv(run_cmd=compat.partial(self._SuccessCommand,

                                            output))

    self.assertTrue(hv.Verify() is None)

  def testVerifyFailing(self):

    hv = self._GetHv(run_cmd=self._FailingCommand)

    self.assertTrue("failed:" in hv.Verify())

  def _StartInstanceCommand(self, inst, paused, failcreate, cmd):

    if cmd == [self.CMD, "info"]:

      output = testutils.ReadTestData("xen-xm-info-4.0.1.txt")

    elif cmd == [self.CMD, "list"]:

      output = testutils.ReadTestData("xen-xm-list-4.0.1-dom0-only.txt")

    elif cmd[:2] == [self.CMD, "create"]:

      args = cmd[2:]

      cfgfile = utils.PathJoin(self.tmpdir, inst.name)

      if paused:

        self.assertEqual(args, ["-p", cfgfile])

      else:

        self.assertEqual(args, [cfgfile])

      if failcreate:

        return self._FailingCommand(cmd)

      output = ""

    else:

      self.fail("Unhandled command: %s" % (cmd, ))

    return self._SuccessCommand(output, cmd)

  def _MakeInstance(self):

    # Copy default parameters

    bep = objects.FillDict(constants.BEC_DEFAULTS, {})

    hvp = objects.FillDict(constants.HVC_DEFAULTS[self.HVNAME], {})

    # Override default VNC password file path

    if constants.HV_VNC_PASSWORD_FILE in hvp:

      hvp[constants.HV_VNC_PASSWORD_FILE] = self.vncpw_path

    disks = [

      (objects.Disk(dev_type=constants.LD_LV, mode=constants.DISK_RDWR),

       utils.PathJoin(self.tmpdir, "disk0")),

      (objects.Disk(dev_type=constants.LD_LV, mode=constants.DISK_RDONLY),

       utils.PathJoin(self.tmpdir, "disk1")),

      ]

    inst = objects.Instance(name="server01.example.com",

                            hvparams=hvp, beparams=bep,

                            osparams={}, nics=[], os="deb1",

                            disks=map(compat.fst, disks))

    inst.UpgradeConfig()

    return (inst, disks)

  def testStartInstance(self):

    (inst, disks) = self._MakeInstance()

    pathutils.LOG_XEN_DIR = self.tmpdir

    for failcreate in [False, True]:

      for paused in [False, True]:

        run_cmd = compat.partial(self._StartInstanceCommand,

                                 inst, paused, failcreate)

        hv = self._GetHv(run_cmd=run_cmd)

        # Ensure instance is not listed

        self.assertTrue(inst.name not in hv.ListInstances())

        # Remove configuration

        cfgfile = utils.PathJoin(self.tmpdir, inst.name)

        utils.RemoveFile(cfgfile)

        if failcreate:

          self.assertRaises(errors.HypervisorError, hv.StartInstance,

                            inst, disks, paused)

          # Check whether a stale config file is left behind

          self.assertFalse(os.path.exists(cfgfile))

        else:

          hv.StartInstance(inst, disks, paused)

          # Check if configuration was updated

          lines = utils.ReadFile(cfgfile).splitlines()

        if constants.HV_VNC_PASSWORD_FILE in inst.hvparams:

          self.assertTrue(("vncpasswd = '%s'" % self.vncpw) in lines)

        else:

          extra = inst.hvparams[constants.HV_KERNEL_ARGS]

          self.assertTrue(("extra = '%s'" % extra) in lines)

  def _StopInstanceCommand(self, instance_name, force, fail, cmd):

    if (cmd == [self.CMD, "list"]):

      output = "Name  ID  Mem  VCPUs  State  Time(s)\n" \

        "Domain-0  0  1023  1  r-----  142691.0\n" \

        "%s  417  128  1  r-----  3.2\n" % instance_name

    elif cmd[:2] == [self.CMD, "destroy"]:

      self.assertEqual(cmd[2:], [instance_name])

      output = ""

    elif not force and cmd[:3] == [self.CMD, "shutdown", "-w"]:

      self.assertEqual(cmd[3:], [instance_name])

      output = ""

    else:

      self.fail("Unhandled command: %s" % (cmd, ))

    if fail:

      # Simulate a failing command

      return self._FailingCommand(cmd)

    else:

      return self._SuccessCommand(output, cmd)

  def testStopInstance(self):

    name = "inst4284.example.com"

    cfgfile = utils.PathJoin(self.tmpdir, name)

    cfgdata = "config file content\n"

    for force in [False, True]:

      for fail in [False, True]:

        utils.WriteFile(cfgfile, data=cfgdata)

        run_cmd = compat.partial(self._StopInstanceCommand, name, force, fail)

        hv = self._GetHv(run_cmd=run_cmd)

        self.assertTrue(os.path.isfile(cfgfile))

        if fail:

          try:

            hv._StopInstance(name, force)

          except errors.HypervisorError, err:

            self.assertTrue(str(err).startswith("xm list failed"),

                            msg=str(err))

          else:

            self.fail("Exception was not raised")

          self.assertEqual(utils.ReadFile(cfgfile), cfgdata,

                           msg=("Configuration was removed when stopping"

                                " instance failed"))

        else:

          hv._StopInstance(name, force)

          self.assertFalse(os.path.exists(cfgfile))

  def _MigrateNonRunningInstCmd(self, cmd):

    if cmd == [self.CMD, "list"]:

      output = testutils.ReadTestData("xen-xm-list-4.0.1-dom0-only.txt")

    else:

      self.fail("Unhandled command: %s" % (cmd, ))

    return self._SuccessCommand(output, cmd)

  def testMigrateInstanceNotRunning(self):

    name = "nonexistinginstance.example.com"

    target = constants.IP4_ADDRESS_LOCALHOST

    port = 14618

    hv = self._GetHv(run_cmd=self._MigrateNonRunningInstCmd)

    for live in [False, True]:

      try:

        hv._MigrateInstance(NotImplemented, name, target, port, live,

                            _ping_fn=NotImplemented)

      except errors.HypervisorError, err:

        self.assertEqual(str(err), "Instance not running, cannot migrate")

      else:

        self.fail("Exception was not raised")

  def _MigrateInstTargetUnreachCmd(self, cmd):

    if cmd == [self.CMD, "list"]:

      output = testutils.ReadTestData("xen-xm-list-4.0.1-four-instances.txt")

    else:

      self.fail("Unhandled command: %s" % (cmd, ))

    return self._SuccessCommand(output, cmd)

  def testMigrateTargetUnreachable(self):

    name = "server01.example.com"

    target = constants.IP4_ADDRESS_LOCALHOST

    port = 28349

    hv = self._GetHv(run_cmd=self._MigrateInstTargetUnreachCmd)

    for live in [False, True]:

      if self.CMD == constants.XEN_CMD_XL:

        # TODO: Detect unreachable targets

        pass

      else:

        try:

          hv._MigrateInstance(NotImplemented, name, target, port, live,

                              _ping_fn=compat.partial(self._FakeTcpPing,

                                                      (target, port), False))

        except errors.HypervisorError, err:

          wanted = "Remote host %s not" % target

          self.assertTrue(str(err).startswith(wanted))

        else:

          self.fail("Exception was not raised")

  def _MigrateInstanceCmd(self, cluster_name, instance_name, target, port,

                          live, fail, cmd):

    if cmd == [self.CMD, "list"]:

      output = testutils.ReadTestData("xen-xm-list-4.0.1-four-instances.txt")

    elif cmd[:2] == [self.CMD, "migrate"]:

      if self.CMD == constants.XEN_CMD_XM:

        args = ["-p", str(port)]

        if live:

          args.append("-l")

      elif self.CMD == constants.XEN_CMD_XL:

        args = [

          "-s", constants.XL_SSH_CMD % cluster_name,

          "-C", utils.PathJoin(self.tmpdir, instance_name),

          ]

      else:

        self.fail("Unknown Xen command '%s'" % self.CMD)

      args.extend([instance_name, target])

      self.assertEqual(cmd[2:], args)

      if fail:

        return self._FailingCommand(cmd)

      output = ""

    else:

      self.fail("Unhandled command: %s" % (cmd, ))

    return self._SuccessCommand(output, cmd)

  def testMigrateInstance(self):

    clustername = "cluster.example.com"

    instname = "server01.example.com"

    target = constants.IP4_ADDRESS_LOCALHOST

    port = 22364

    for live in [False, True]:

      for fail in [False, True]:

        ping_fn = \

          testutils.CallCounter(compat.partial(self._FakeTcpPing,

                                               (target, port), True))

        run_cmd = \

          compat.partial(self._MigrateInstanceCmd,

                         clustername, instname, target, port, live,

                         fail)

        hv = self._GetHv(run_cmd=run_cmd)

        if fail:

          try:

            hv._MigrateInstance(clustername, instname, target, port, live,

                                _ping_fn=ping_fn)

          except errors.HypervisorError, err:

            self.assertTrue(str(err).startswith("Failed to migrate instance"))

          else:

            self.fail("Exception was not raised")

        else:

          hv._MigrateInstance(clustername, instname, target, port, live,

                              _ping_fn=ping_fn)

        if self.CMD == constants.XEN_CMD_XM:

          expected_pings = 1

        else:

          expected_pings = 0

        self.assertEqual(ping_fn.Count(), expected_pings)

  def _GetNodeInfoCmd(self, fail, cmd):

    if cmd == [self.CMD, "info"]:

      if fail:

        return self._FailingCommand(cmd)

      else:

        output = testutils.ReadTestData("xen-xm-info-4.0.1.txt")

    elif cmd == [self.CMD, "list"]:

      if fail:

        self.fail("'xm list' shouldn't be called when 'xm info' failed")

      else:

        output = testutils.ReadTestData("xen-xm-list-4.0.1-four-instances.txt")

    else:

      self.fail("Unhandled command: %s" % (cmd, ))

    return self._SuccessCommand(output, cmd)

  def testGetNodeInfo(self):

    run_cmd = compat.partial(self._GetNodeInfoCmd, False)

    hv = self._GetHv(run_cmd=run_cmd)

    result = hv.GetNodeInfo()

    self.assertEqual(result["hv_version"], (4, 0))

    self.assertEqual(result["memory_free"], 8004)

  def testGetNodeInfoFailing(self):

    run_cmd = compat.partial(self._GetNodeInfoCmd, True)

    hv = self._GetHv(run_cmd=run_cmd)

    self.assertTrue(hv.GetNodeInfo() is None)

def _MakeTestClass(cls, cmd):

  """Makes a class for testing.

  The returned class has structure as shown in the following pseudo code:

    class Test{cls.__name__}{cmd}(_TestXenHypervisor, unittest.TestCase):

      TARGET = {cls}

      CMD = {cmd}

      HVNAME = {Hypervisor name retrieved using class}

  @type cls: class

  @param cls: Hypervisor class to be tested

  @type cmd: string

  @param cmd: Hypervisor command

  @rtype: tuple

  @return: Class name and class object (not instance)

  """

  name = "Test%sCmd%s" % (cls.__name__, cmd.title())