Synnefo » snf-ganeti » ganeti-local

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# Copyright (C) 2006, 2007, 2008 Google Inc.

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# This program is free software; you can redistribute it and/or modify

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# the Free Software Foundation; either version 2 of the License, or

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# General Public License for more details.

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# You should have received a copy of the GNU General Public License

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# 02110-1301, USA.

"""Base class for all hypervisors

The syntax for the _CHECK variables and the contents of the PARAMETERS

dict is the same, see the docstring for L{BaseHypervisor.PARAMETERS}.

@var _FILE_CHECK: stub for file checks, without the required flag

@var _DIR_CHECK: stub for directory checks, without the required flag

@var REQ_FILE_CHECK: mandatory file parameter

@var OPT_FILE_CHECK: optional file parameter

@var REQ_DIR_CHECK: mandatory directory parametr

@var OPT_DIR_CHECK: optional directory parameter

@var NO_CHECK: parameter without any checks at all

@var REQUIRED_CHECK: parameter required to exist (and non-false), but

    without other checks; beware that this can't be used for boolean

    parameters, where you should use NO_CHECK or a custom checker

"""

import os

import re

from ganeti import errors

from ganeti import utils

# Read the BaseHypervisor.PARAMETERS docstring for the syntax of the

# _CHECK values

# must be afile

_FILE_CHECK = (utils.IsNormAbsPath, "must be an absolute normalized path",

              os.path.isfile, "not found or not a file")

# must be a directory

_DIR_CHECK = (utils.IsNormAbsPath, "must be an absolute normalized path",

             os.path.isdir, "not found or not a directory")

# nice wrappers for users

REQ_FILE_CHECK = (True, ) + _FILE_CHECK

OPT_FILE_CHECK = (False, ) + _FILE_CHECK

REQ_DIR_CHECK = (True, ) + _DIR_CHECK

OPT_DIR_CHECK = (False, ) + _DIR_CHECK

# no checks at all

NO_CHECK = (False, None, None, None, None)

# required, but no other checks

REQUIRED_CHECK = (True, None, None, None, None)

def ParamInSet(required, my_set):

  """Builds parameter checker for set membership.

  @type required: boolean

  @param required: whether this is a required parameter

  @type my_set: tuple, list or set

  @param my_set: allowed values set

  """

  fn = lambda x: x in my_set

  err = ("The value must be one of: %s" % utils.CommaJoin(my_set))

  return (required, fn, err, None, None)

class BaseHypervisor(object):

  """Abstract virtualisation technology interface

  The goal is that all aspects of the virtualisation technology are

  abstracted away from the rest of code.

  @cvar PARAMETERS: a dict of parameter name: check type; the check type is

      a five-tuple containing:

          - the required flag (boolean)

          - a function to check for syntax, that will be used in

            L{CheckParameterSyntax}, in the master daemon process

          - an error message for the above function

          - a function to check for parameter validity on the remote node,

            in the L{ValidateParameters} function

          - an error message for the above function

  """

  PARAMETERS = {}

  ANCILLARY_FILES = []

  def __init__(self):

    pass

  def StartInstance(self, instance, block_devices):

    """Start an instance."""

    raise NotImplementedError

  def StopInstance(self, instance, force=False):

    """Stop an instance."""

    raise NotImplementedError

  def RebootInstance(self, instance):

    """Reboot an instance."""

    raise NotImplementedError

  def ListInstances(self):

    """Get the list of running instances."""

    raise NotImplementedError

  def GetInstanceInfo(self, instance_name):

    """Get instance properties.

    @type instance_name: string

    @param instance_name: the instance name

    @return: tuple (name, id, memory, vcpus, state, times)

    """

    raise NotImplementedError

  def GetAllInstancesInfo(self):

    """Get properties of all instances.

    @return: list of tuples (name, id, memory, vcpus, stat, times)

    """

    raise NotImplementedError

  def GetNodeInfo(self):

    """Return information about the node.

    @return: a dict with the following keys (values in MiB):

          - memory_total: the total memory size on the node

          - memory_free: the available memory on the node for instances

          - memory_dom0: the memory used by the node itself, if available

    """

    raise NotImplementedError

  @classmethod

  def GetShellCommandForConsole(cls, instance, hvparams, beparams):

    """Return a command for connecting to the console of an instance.

    """

    raise NotImplementedError

  @classmethod

  def GetAncillaryFiles(cls):

    """Return a list of ancillary files to be copied to all nodes as ancillary

    configuration files.

    @rtype: list of strings

    @return: list of absolute paths of files to ship cluster-wide

    """

    # By default we return a member variable, so that if an hypervisor has just

    # a static list of files it doesn't have to override this function.

    return cls.ANCILLARY_FILES

  def Verify(self):

    """Verify the hypervisor.

    """

    raise NotImplementedError

  def MigrationInfo(self, instance):

    """Get instance information to perform a migration.

    By default assume no information is needed.

    @type instance: L{objects.Instance}

    @param instance: instance to be migrated

    @rtype: string/data (opaque)

    @return: instance migration information - serialized form

    """

    return ''

  def AcceptInstance(self, instance, info, target):

    """Prepare to accept an instance.

    By default assume no preparation is needed.

    @type instance: L{objects.Instance}

    @param instance: instance to be accepted

    @type info: string/data (opaque)

    @param info: migration information, from the source node

    @type target: string

    @param target: target host (usually ip), on this node

    """

    pass

  def FinalizeMigration(self, instance, info, success):

    """Finalized an instance migration.

    Should finalize or revert any preparation done to accept the instance.

    Since by default we do no preparation, we also don't have anything to do

    @type instance: L{objects.Instance}

    @param instance: instance whose migration is being aborted

    @type info: string/data (opaque)

    @param info: migration information, from the source node

    @type success: boolean

    @param success: whether the migration was a success or a failure

    """

    pass

  def MigrateInstance(self, name, target, live):

    """Migrate an instance.

    @type name: string

    @param name: name of the instance to be migrated

    @type target: string

    @param target: hostname (usually ip) of the target node

    @type live: boolean

    @param live: whether to do a live or non-live migration

    """

    raise NotImplementedError

  @classmethod

  def CheckParameterSyntax(cls, hvparams):

    """Check the given parameters for validity.

    This should check the passed set of parameters for

    validity. Classes should extend, not replace, this function.

    @type hvparams:  dict

    @param hvparams: dictionary with parameter names/value

    @raise errors.HypervisorError: when a parameter is not valid

    """

    for key in hvparams:

      if key not in cls.PARAMETERS:

        raise errors.HypervisorError("Parameter '%s' is not supported" % key)

    # cheap tests that run on the master, should not access the world

    for name, (required, check_fn, errstr, _, _) in cls.PARAMETERS.items():

      if name not in hvparams:

        raise errors.HypervisorError("Parameter '%s' is missing" % name)

      value = hvparams[name]

      if not required and not value:

        continue

      if not value:

        raise errors.HypervisorError("Parameter '%s' is required but"

                                     " is currently not defined" % (name, ))

      if check_fn is not None and not check_fn(value):

        raise errors.HypervisorError("Parameter '%s' fails syntax"

                                     " check: %s (current value: '%s')" %

                                     (name, errstr, value))

  @classmethod

  def ValidateParameters(cls, hvparams):

    """Check the given parameters for validity.

    This should check the passed set of parameters for

    validity. Classes should extend, not replace, this function.

    @type hvparams:  dict

    @param hvparams: dictionary with parameter names/value

    @raise errors.HypervisorError: when a parameter is not valid

    """

    for name, (required, _, _, check_fn, errstr) in cls.PARAMETERS.items():

      value = hvparams[name]

      if not required and not value:

        continue

      if check_fn is not None and not check_fn(value):

        raise errors.HypervisorError("Parameter '%s' fails"

                                     " validation: %s (current value: '%s')" %

                                     (name, errstr, value))

  def GetLinuxNodeInfo(self):

    """For linux systems, return actual OS information.

    This is an abstraction for all non-hypervisor-based classes, where

    the node actually sees all the memory and CPUs via the /proc

    interface and standard commands. The other case if for example

    xen, where you only see the hardware resources via xen-specific

    tools.

    @return: a dict with the following keys (values in MiB):

          - memory_total: the total memory size on the node

          - memory_free: the available memory on the node for instances

          - memory_dom0: the memory used by the node itself, if available

    """

    try:

      fh = file("/proc/meminfo")

      try:

        data = fh.readlines()

      finally:

        fh.close()

    except EnvironmentError, err:

      raise errors.HypervisorError("Failed to list node info: %s" % (err,))

    result = {}

    sum_free = 0

    try:

      for line in data:

        splitfields = line.split(":", 1)

        if len(splitfields) > 1:

          key = splitfields[0].strip()

          val = splitfields[1].strip()

          if key == 'MemTotal':

            result['memory_total'] = int(val.split()[0])/1024

          elif key in ('MemFree', 'Buffers', 'Cached'):

            sum_free += int(val.split()[0])/1024

          elif key == 'Active':

            result['memory_dom0'] = int(val.split()[0])/1024

    except (ValueError, TypeError), err:

      raise errors.HypervisorError("Failed to compute memory usage: %s" %

                                   (err,))

    result['memory_free'] = sum_free

    cpu_total = 0

    try:

      fh = open("/proc/cpuinfo")

      try:

        cpu_total = len(re.findall("(?m)^processor\s*:\s*[0-9]+\s*$",

                                   fh.read()))

      finally:

        fh.close()

    except EnvironmentError, err:

      raise errors.HypervisorError("Failed to list node info: %s" % (err,))

    result['cpu_total'] = cpu_total

    # FIXME: export correct data here

    result['cpu_nodes'] = 1

    result['cpu_sockets'] = 1

    return result