Synnefo » snf-ganeti

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"""OpCodes module

This module implements the data structures which define the cluster

operations - the so-called opcodes.

Every operation which modifies the cluster state is expressed via

opcodes.

"""

# this are practically structures, so disable the message about too

# few public methods:

# pylint: disable-msg=R0903

import logging

import re

import operator

from ganeti import constants

from ganeti import errors

from ganeti import ht

# Common opcode attributes

#: output fields for a query operation

_POutputFields = ("output_fields", ht.NoDefault, ht.TListOf(ht.TNonEmptyString),

                  "Selected output fields")

#: the shutdown timeout

_PShutdownTimeout = \

  ("shutdown_timeout", constants.DEFAULT_SHUTDOWN_TIMEOUT, ht.TPositiveInt,

   "How long to wait for instance to shut down")

#: the force parameter

_PForce = ("force", False, ht.TBool, "Whether to force the operation")

#: a required instance name (for single-instance LUs)

_PInstanceName = ("instance_name", ht.NoDefault, ht.TNonEmptyString,

                  "Instance name")

#: Whether to ignore offline nodes

_PIgnoreOfflineNodes = ("ignore_offline_nodes", False, ht.TBool,

                        "Whether to ignore offline nodes")

#: a required node name (for single-node LUs)

_PNodeName = ("node_name", ht.NoDefault, ht.TNonEmptyString, "Node name")

#: a required node group name (for single-group LUs)

_PGroupName = ("group_name", ht.NoDefault, ht.TNonEmptyString, "Group name")

#: Migration type (live/non-live)

_PMigrationMode = ("mode", None,

                   ht.TOr(ht.TNone, ht.TElemOf(constants.HT_MIGRATION_MODES)),

                   "Migration mode")

#: Obsolete 'live' migration mode (boolean)

_PMigrationLive = ("live", None, ht.TMaybeBool,

                   "Legacy setting for live migration, do not use")

#: Tag type

_PTagKind = ("kind", ht.NoDefault, ht.TElemOf(constants.VALID_TAG_TYPES), None)

#: List of tag strings

_PTags = ("tags", ht.NoDefault, ht.TListOf(ht.TNonEmptyString), None)

_PForceVariant = ("force_variant", False, ht.TBool,

                  "Whether to force an unknown OS variant")

_PWaitForSync = ("wait_for_sync", True, ht.TBool,

                 "Whether to wait for the disk to synchronize")

_PIgnoreConsistency = ("ignore_consistency", False, ht.TBool,

                       "Whether to ignore disk consistency")

_PStorageName = ("name", ht.NoDefault, ht.TMaybeString, "Storage name")

_PUseLocking = ("use_locking", False, ht.TBool,

                "Whether to use synchronization")

_PNameCheck = ("name_check", True, ht.TBool, "Whether to check name")

_PNodeGroupAllocPolicy = \

  ("alloc_policy", None,

   ht.TOr(ht.TNone, ht.TElemOf(constants.VALID_ALLOC_POLICIES)),

   "Instance allocation policy")

_PGroupNodeParams = ("ndparams", None, ht.TMaybeDict,

                     "Default node parameters for group")

_PQueryWhat = ("what", ht.NoDefault, ht.TElemOf(constants.QR_VIA_OP),

               "Resource(s) to query for")

_PEarlyRelease = ("early_release", False, ht.TBool,

                  "Whether to release locks as soon as possible")

_PIpCheckDoc = "Whether to ensure instance's IP address is inactive"

#: Do not remember instance state changes

_PNoRemember = ("no_remember", False, ht.TBool,

                "Do not remember the state change")

#: Target node for instance migration/failover

_PMigrationTargetNode = ("target_node", None, ht.TMaybeString,

                         "Target node for shared-storage instances")

_PStartupPaused = ("startup_paused", False, ht.TBool,

                   "Pause instance at startup")

#: OP_ID conversion regular expression

_OPID_RE = re.compile("([a-z])([A-Z])")

#: Utility function for L{OpClusterSetParams}

_TestClusterOsList = ht.TOr(ht.TNone,

  ht.TListOf(ht.TAnd(ht.TList, ht.TIsLength(2),

    ht.TMap(ht.WithDesc("GetFirstItem")(operator.itemgetter(0)),

            ht.TElemOf(constants.DDMS_VALUES)))))

# TODO: Generate check from constants.INIC_PARAMS_TYPES

#: Utility function for testing NIC definitions

_TestNicDef = ht.TDictOf(ht.TElemOf(constants.INIC_PARAMS),

                         ht.TOr(ht.TNone, ht.TNonEmptyString))

_SUMMARY_PREFIX = {

  "CLUSTER_": "C_",

  "GROUP_": "G_",

  "NODE_": "N_",

  "INSTANCE_": "I_",

  }

def _NameToId(name):

  """Convert an opcode class name to an OP_ID.

  @type name: string

  @param name: the class name, as OpXxxYyy

  @rtype: string

  @return: the name in the OP_XXXX_YYYY format

  """

  if not name.startswith("Op"):

    return None

  # Note: (?<=[a-z])(?=[A-Z]) would be ideal, since it wouldn't

  # consume any input, and hence we would just have all the elements

  # in the list, one by one; but it seems that split doesn't work on

  # non-consuming input, hence we have to process the input string a

  # bit

  name = _OPID_RE.sub(r"\1,\2", name)

  elems = name.split(",")

  return "_".join(n.upper() for n in elems)

def RequireFileStorage():

  """Checks that file storage is enabled.

  While it doesn't really fit into this module, L{utils} was deemed too large

  of a dependency to be imported for just one or two functions.

  @raise errors.OpPrereqError: when file storage is disabled

  """

  if not constants.ENABLE_FILE_STORAGE:

    raise errors.OpPrereqError("File storage disabled at configure time",

                               errors.ECODE_INVAL)

def RequireSharedFileStorage():

  """Checks that shared file storage is enabled.

  While it doesn't really fit into this module, L{utils} was deemed too large

  of a dependency to be imported for just one or two functions.

  @raise errors.OpPrereqError: when shared file storage is disabled

  """

  if not constants.ENABLE_SHARED_FILE_STORAGE:

    raise errors.OpPrereqError("Shared file storage disabled at"

                               " configure time", errors.ECODE_INVAL)

@ht.WithDesc("CheckFileStorage")

def _CheckFileStorage(value):

  """Ensures file storage is enabled if used.

  """

  if value == constants.DT_FILE:

    RequireFileStorage()

  elif value == constants.DT_SHARED_FILE:

    RequireSharedFileStorage()

  return True

_CheckDiskTemplate = ht.TAnd(ht.TElemOf(constants.DISK_TEMPLATES),

                             _CheckFileStorage)

def _CheckStorageType(storage_type):

  """Ensure a given storage type is valid.

  """

  if storage_type not in constants.VALID_STORAGE_TYPES:

    raise errors.OpPrereqError("Unknown storage type: %s" % storage_type,

                               errors.ECODE_INVAL)

  if storage_type == constants.ST_FILE:

    RequireFileStorage()

  return True

#: Storage type parameter

_PStorageType = ("storage_type", ht.NoDefault, _CheckStorageType,

                 "Storage type")

class _AutoOpParamSlots(type):

  """Meta class for opcode definitions.

  """

  def __new__(mcs, name, bases, attrs):

    """Called when a class should be created.

    @param mcs: The meta class

    @param name: Name of created class

    @param bases: Base classes

    @type attrs: dict

    @param attrs: Class attributes

    """

    assert "__slots__" not in attrs, \

      "Class '%s' defines __slots__ when it should use OP_PARAMS" % name

    assert "OP_ID" not in attrs, "Class '%s' defining OP_ID" % name

    attrs["OP_ID"] = _NameToId(name)

    # Always set OP_PARAMS to avoid duplicates in BaseOpCode.GetAllParams

    params = attrs.setdefault("OP_PARAMS", [])

    # Use parameter names as slots

    slots = [pname for (pname, _, _, _) in params]

    assert "OP_DSC_FIELD" not in attrs or attrs["OP_DSC_FIELD"] in slots, \

      "Class '%s' uses unknown field in OP_DSC_FIELD" % name

    attrs["__slots__"] = slots

    return type.__new__(mcs, name, bases, attrs)

class BaseOpCode(object):

  """A simple serializable object.

  This object serves as a parent class for OpCode without any custom

  field handling.

  """

  # pylint: disable-msg=E1101

  # as OP_ID is dynamically defined

  __metaclass__ = _AutoOpParamSlots

  def __init__(self, **kwargs):

    """Constructor for BaseOpCode.

    The constructor takes only keyword arguments and will set

    attributes on this object based on the passed arguments. As such,

    it means that you should not pass arguments which are not in the

    __slots__ attribute for this class.

    """

    slots = self._all_slots()

    for key in kwargs:

      if key not in slots:

        raise TypeError("Object %s doesn't support the parameter '%s'" %

                        (self.__class__.__name__, key))

      setattr(self, key, kwargs[key])

  def __getstate__(self):

    """Generic serializer.

    This method just returns the contents of the instance as a

    dictionary.

    @rtype:  C{dict}

    @return: the instance attributes and their values

    """

    state = {}

    for name in self._all_slots():

      if hasattr(self, name):

        state[name] = getattr(self, name)

    return state

  def __setstate__(self, state):

    """Generic unserializer.

    This method just restores from the serialized state the attributes

    of the current instance.

    @param state: the serialized opcode data

    @type state:  C{dict}

    """

    if not isinstance(state, dict):

      raise ValueError("Invalid data to __setstate__: expected dict, got %s" %

                       type(state))

    for name in self._all_slots():

      if name not in state and hasattr(self, name):

        delattr(self, name)

    for name in state:

      setattr(self, name, state[name])

  @classmethod

  def _all_slots(cls):

    """Compute the list of all declared slots for a class.

    """

    slots = []

    for parent in cls.__mro__:

      slots.extend(getattr(parent, "__slots__", []))

    return slots

  @classmethod

  def GetAllParams(cls):

    """Compute list of all parameters for an opcode.

    """

    slots = []

    for parent in cls.__mro__:

      slots.extend(getattr(parent, "OP_PARAMS", []))

    return slots

  def Validate(self, set_defaults):

    """Validate opcode parameters, optionally setting default values.

    @type set_defaults: bool

    @param set_defaults: Whether to set default values

    @raise errors.OpPrereqError: When a parameter value doesn't match

                                 requirements

    """

    for (attr_name, default, test, _) in self.GetAllParams():

      assert test == ht.NoType or callable(test)

      if not hasattr(self, attr_name):

        if default == ht.NoDefault:

          raise errors.OpPrereqError("Required parameter '%s.%s' missing" %

                                     (self.OP_ID, attr_name),

                                     errors.ECODE_INVAL)

        elif set_defaults:

          if callable(default):

            dval = default()

          else:

            dval = default

          setattr(self, attr_name, dval)

      if test == ht.NoType:

        # no tests here

        continue

      if set_defaults or hasattr(self, attr_name):

        attr_val = getattr(self, attr_name)

        if not test(attr_val):

          logging.error("OpCode %s, parameter %s, has invalid type %s/value %s",

                        self.OP_ID, attr_name, type(attr_val), attr_val)

          raise errors.OpPrereqError("Parameter '%s.%s' fails validation" %

                                     (self.OP_ID, attr_name),

                                     errors.ECODE_INVAL)

class OpCode(BaseOpCode):

  """Abstract OpCode.

  This is the root of the actual OpCode hierarchy. All clases derived

  from this class should override OP_ID.

  @cvar OP_ID: The ID of this opcode. This should be unique amongst all

               children of this class.

  @cvar OP_DSC_FIELD: The name of a field whose value will be included in the

                      string returned by Summary(); see the docstring of that

                      method for details).

  @cvar OP_PARAMS: List of opcode attributes, the default values they should

                   get if not already defined, and types they must match.

  @cvar WITH_LU: Boolean that specifies whether this should be included in

      mcpu's dispatch table

  @ivar dry_run: Whether the LU should be run in dry-run mode, i.e. just

                 the check steps

  @ivar priority: Opcode priority for queue

  """

  # pylint: disable-msg=E1101

  # as OP_ID is dynamically defined

  WITH_LU = True

  OP_PARAMS = [

    ("dry_run", None, ht.TMaybeBool, "Run checks only, don't execute"),

    ("debug_level", None, ht.TOr(ht.TNone, ht.TPositiveInt), "Debug level"),

    ("priority", constants.OP_PRIO_DEFAULT,

     ht.TElemOf(constants.OP_PRIO_SUBMIT_VALID), "Opcode priority"),

    ]

  def __getstate__(self):

    """Specialized getstate for opcodes.

    This method adds to the state dictionary the OP_ID of the class,

    so that on unload we can identify the correct class for

    instantiating the opcode.

    @rtype:   C{dict}

    @return:  the state as a dictionary

    """

    data = BaseOpCode.__getstate__(self)

    data["OP_ID"] = self.OP_ID

    return data

  @classmethod

  def LoadOpCode(cls, data):

    """Generic load opcode method.

    The method identifies the correct opcode class from the dict-form

    by looking for a OP_ID key, if this is not found, or its value is

    not available in this module as a child of this class, we fail.

    @type data:  C{dict}

    @param data: the serialized opcode

    """

    if not isinstance(data, dict):

      raise ValueError("Invalid data to LoadOpCode (%s)" % type(data))

    if "OP_ID" not in data:

      raise ValueError("Invalid data to LoadOpcode, missing OP_ID")

    op_id = data["OP_ID"]

    op_class = None

    if op_id in OP_MAPPING:

      op_class = OP_MAPPING[op_id]

    else:

      raise ValueError("Invalid data to LoadOpCode: OP_ID %s unsupported" %

                       op_id)

    op = op_class()

    new_data = data.copy()

    del new_data["OP_ID"]

    op.__setstate__(new_data)

    return op

  def Summary(self):

    """Generates a summary description of this opcode.

    The summary is the value of the OP_ID attribute (without the "OP_"

    prefix), plus the value of the OP_DSC_FIELD attribute, if one was

    defined; this field should allow to easily identify the operation

    (for an instance creation job, e.g., it would be the instance

    name).

    """

    assert self.OP_ID is not None and len(self.OP_ID) > 3

    # all OP_ID start with OP_, we remove that

    txt = self.OP_ID[3:]

    field_name = getattr(self, "OP_DSC_FIELD", None)

    if field_name:

      field_value = getattr(self, field_name, None)

      if isinstance(field_value, (list, tuple)):

        field_value = ",".join(str(i) for i in field_value)

      txt = "%s(%s)" % (txt, field_value)

    return txt

  def TinySummary(self):

    """Generates a compact summary description of the opcode.

    """

    assert self.OP_ID.startswith("OP_")

    text = self.OP_ID[3:]

    for (prefix, supplement) in _SUMMARY_PREFIX.items():

      if text.startswith(prefix):

        return supplement + text[len(prefix):]

    return text

# cluster opcodes

class OpClusterPostInit(OpCode):

  """Post cluster initialization.

  This opcode does not touch the cluster at all. Its purpose is to run hooks

  after the cluster has been initialized.

  """

class OpClusterDestroy(OpCode):

  """Destroy the cluster.

  This opcode has no other parameters. All the state is irreversibly

  lost after the execution of this opcode.

  """

class OpClusterQuery(OpCode):

  """Query cluster information."""

class OpClusterVerifyConfig(OpCode):

  """Verify the cluster config.

  """

  OP_PARAMS = [

    ("verbose", False, ht.TBool, None),

    ("error_codes", False, ht.TBool, None),

    ("debug_simulate_errors", False, ht.TBool, None),

    ]

class OpClusterVerifyGroup(OpCode):

  """Run verify on a node group from the cluster.

  @type skip_checks: C{list}

  @ivar skip_checks: steps to be skipped from the verify process; this

                     needs to be a subset of

                     L{constants.VERIFY_OPTIONAL_CHECKS}; currently

                     only L{constants.VERIFY_NPLUSONE_MEM} can be passed

  """

  OP_DSC_FIELD = "group_name"

  OP_PARAMS = [

    ("group_name", ht.NoDefault, ht.TNonEmptyString, None),

    ("skip_checks", ht.EmptyList,

     ht.TListOf(ht.TElemOf(constants.VERIFY_OPTIONAL_CHECKS)), None),

    ("verbose", False, ht.TBool, None),

    ("error_codes", False, ht.TBool, None),

    ("debug_simulate_errors", False, ht.TBool, None),

    ]

class OpClusterVerifyDisks(OpCode):

  """Verify the cluster disks.

  Parameters: none

  Result: a tuple of four elements:

    - list of node names with bad data returned (unreachable, etc.)

    - dict of node names with broken volume groups (values: error msg)

    - list of instances with degraded disks (that should be activated)

    - dict of instances with missing logical volumes (values: (node, vol)

      pairs with details about the missing volumes)

  In normal operation, all lists should be empty. A non-empty instance

  list (3rd element of the result) is still ok (errors were fixed) but

  non-empty node list means some node is down, and probably there are

  unfixable drbd errors.

  Note that only instances that are drbd-based are taken into

  consideration. This might need to be revisited in the future.

  """

class OpClusterRepairDiskSizes(OpCode):

  """Verify the disk sizes of the instances and fixes configuration

  mimatches.

  Parameters: optional instances list, in case we want to restrict the

  checks to only a subset of the instances.

  Result: a list of tuples, (instance, disk, new-size) for changed

  configurations.

  In normal operation, the list should be empty.

  @type instances: list

  @ivar instances: the list of instances to check, or empty for all instances

  """

  OP_PARAMS = [

    ("instances", ht.EmptyList, ht.TListOf(ht.TNonEmptyString), None),

    ]

class OpClusterConfigQuery(OpCode):

  """Query cluster configuration values."""

  OP_PARAMS = [

    _POutputFields

    ]

class OpClusterRename(OpCode):

  """Rename the cluster.

  @type name: C{str}

  @ivar name: The new name of the cluster. The name and/or the master IP

              address will be changed to match the new name and its IP

              address.

  """

  OP_DSC_FIELD = "name"

  OP_PARAMS = [

    ("name", ht.NoDefault, ht.TNonEmptyString, None),

    ]

class OpClusterSetParams(OpCode):

  """Change the parameters of the cluster.

  @type vg_name: C{str} or C{None}

  @ivar vg_name: The new volume group name or None to disable LVM usage.

  """

  OP_PARAMS = [

    ("vg_name", None, ht.TMaybeString, "Volume group name"),

    ("enabled_hypervisors", None,

     ht.TOr(ht.TAnd(ht.TListOf(ht.TElemOf(constants.HYPER_TYPES)), ht.TTrue),

            ht.TNone),

     "List of enabled hypervisors"),

    ("hvparams", None, ht.TOr(ht.TDictOf(ht.TNonEmptyString, ht.TDict),

                              ht.TNone),

     "Cluster-wide hypervisor parameter defaults, hypervisor-dependent"),

    ("beparams", None, ht.TOr(ht.TDict, ht.TNone),

     "Cluster-wide backend parameter defaults"),

    ("os_hvp", None, ht.TOr(ht.TDictOf(ht.TNonEmptyString, ht.TDict),

                            ht.TNone),

     "Cluster-wide per-OS hypervisor parameter defaults"),

    ("osparams", None, ht.TOr(ht.TDictOf(ht.TNonEmptyString, ht.TDict),

                              ht.TNone),

     "Cluster-wide OS parameter defaults"),

    ("candidate_pool_size", None, ht.TOr(ht.TStrictPositiveInt, ht.TNone),

     "Master candidate pool size"),

    ("uid_pool", None, ht.NoType,

     "Set UID pool, must be list of lists describing UID ranges (two items,"

     " start and end inclusive)"),

    ("add_uids", None, ht.NoType,

     "Extend UID pool, must be list of lists describing UID ranges (two"

     " items, start and end inclusive) to be added"),

    ("remove_uids", None, ht.NoType,

     "Shrink UID pool, must be list of lists describing UID ranges (two"

     " items, start and end inclusive) to be removed"),

    ("maintain_node_health", None, ht.TMaybeBool,

     "Whether to automatically maintain node health"),

    ("prealloc_wipe_disks", None, ht.TMaybeBool,

     "Whether to wipe disks before allocating them to instances"),

    ("nicparams", None, ht.TMaybeDict, "Cluster-wide NIC parameter defaults"),

    ("ndparams", None, ht.TMaybeDict, "Cluster-wide node parameter defaults"),

    ("drbd_helper", None, ht.TOr(ht.TString, ht.TNone), "DRBD helper program"),

    ("default_iallocator", None, ht.TOr(ht.TString, ht.TNone),

     "Default iallocator for cluster"),

    ("master_netdev", None, ht.TOr(ht.TString, ht.TNone),

     "Master network device"),

    ("reserved_lvs", None, ht.TOr(ht.TListOf(ht.TNonEmptyString), ht.TNone),

     "List of reserved LVs"),

    ("hidden_os", None, _TestClusterOsList,

     "Modify list of hidden operating systems. Each modification must have"

     " two items, the operation and the OS name. The operation can be"

     " ``%s`` or ``%s``." % (constants.DDM_ADD, constants.DDM_REMOVE)),

    ("blacklisted_os", None, _TestClusterOsList,

     "Modify list of blacklisted operating systems. Each modification must have"

     " two items, the operation and the OS name. The operation can be"

     " ``%s`` or ``%s``." % (constants.DDM_ADD, constants.DDM_REMOVE)),

    ]

class OpClusterRedistConf(OpCode):

  """Force a full push of the cluster configuration.

  """

class OpQuery(OpCode):

  """Query for resources/items.

  @ivar what: Resources to query for, must be one of L{constants.QR_VIA_OP}

  @ivar fields: List of fields to retrieve

  @ivar filter: Query filter

  """

  OP_PARAMS = [

    _PQueryWhat,

    ("fields", ht.NoDefault, ht.TListOf(ht.TNonEmptyString),

     "Requested fields"),

    ("filter", None, ht.TOr(ht.TNone, ht.TListOf),

     "Query filter"),

    ]

class OpQueryFields(OpCode):

  """Query for available resource/item fields.

  @ivar what: Resources to query for, must be one of L{constants.QR_VIA_OP}

  @ivar fields: List of fields to retrieve

  """

  OP_PARAMS = [

    _PQueryWhat,

    ("fields", None, ht.TOr(ht.TNone, ht.TListOf(ht.TNonEmptyString)),

     "Requested fields; if not given, all are returned"),

    ]