Synnefo » snf-ganeti

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#

# Copyright (C) 2010, 2011 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

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# 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.

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# 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.

"""Module for query operations

How it works:

  - Add field definitions

    - See how L{NODE_FIELDS} is built

    - Each field gets:

      - Query field definition (L{objects.QueryFieldDefinition}, use

        L{_MakeField} for creating), containing:

          - Name, must be lowercase and match L{FIELD_NAME_RE}

          - Title for tables, must not contain whitespace and match

            L{TITLE_RE}

          - Value data type, e.g. L{constants.QFT_NUMBER}

      - Data request type, see e.g. C{NQ_*}

      - A retrieval function, see L{Query.__init__} for description

    - Pass list of fields through L{_PrepareFieldList} for preparation and

      checks

  - Instantiate L{Query} with prepared field list definition and selected fields

  - Call L{Query.RequestedData} to determine what data to collect/compute

  - Call L{Query.Query} or L{Query.OldStyleQuery} with collected data and use

    result

      - Data container must support iteration using C{__iter__}

      - Items are passed to retrieval functions and can have any format

  - Call L{Query.GetFields} to get list of definitions for selected fields

@attention: Retrieval functions must be idempotent. They can be called multiple

  times, in any order and any number of times. This is important to keep in

  mind for implementing filters in the future.

"""

import logging

import operator

import re

from ganeti import constants

from ganeti import errors

from ganeti import utils

from ganeti import compat

from ganeti import objects

from ganeti import ht

from ganeti.constants import (QFT_UNKNOWN, QFT_TEXT, QFT_BOOL, QFT_NUMBER,

                              QFT_UNIT, QFT_TIMESTAMP, QFT_OTHER,

                              RS_NORMAL, RS_UNKNOWN, RS_NODATA,

                              RS_UNAVAIL, RS_OFFLINE)

# Constants for requesting data from the caller/data provider. Each property

# collected/computed separately by the data provider should have its own to

# only collect the requested data and not more.

(NQ_CONFIG,

 NQ_INST,

 NQ_LIVE,

 NQ_GROUP,

 NQ_OOB) = range(1, 6)

(IQ_CONFIG,

 IQ_LIVE,

 IQ_DISKUSAGE) = range(100, 103)

(LQ_MODE,

 LQ_OWNER,

 LQ_PENDING) = range(10, 13)

(GQ_CONFIG,

 GQ_NODE,

 GQ_INST) = range(200, 203)

FIELD_NAME_RE = re.compile(r"^[a-z0-9/._]+$")

TITLE_RE = re.compile(r"^[^\s]+$")

#: Verification function for each field type

_VERIFY_FN = {

  QFT_UNKNOWN: ht.TNone,

  QFT_TEXT: ht.TString,

  QFT_BOOL: ht.TBool,

  QFT_NUMBER: ht.TInt,

  QFT_UNIT: ht.TInt,

  QFT_TIMESTAMP: ht.TOr(ht.TInt, ht.TFloat),

  QFT_OTHER: lambda _: True,

  }

# Unique objects for special field statuses

_FS_UNKNOWN = object()

_FS_NODATA = object()

_FS_UNAVAIL = object()

_FS_OFFLINE = object()

#: VType to QFT mapping

_VTToQFT = {

  # TODO: fix validation of empty strings

  constants.VTYPE_STRING: QFT_OTHER, # since VTYPE_STRINGs can be empty

  constants.VTYPE_MAYBE_STRING: QFT_OTHER,

  constants.VTYPE_BOOL: QFT_BOOL,

  constants.VTYPE_SIZE: QFT_UNIT,

  constants.VTYPE_INT: QFT_NUMBER,

  }

def _GetUnknownField(ctx, item): # pylint: disable-msg=W0613

  """Gets the contents of an unknown field.

  """

  return _FS_UNKNOWN

def _GetQueryFields(fielddefs, selected):

  """Calculates the internal list of selected fields.

  Unknown fields are returned as L{constants.QFT_UNKNOWN}.

  @type fielddefs: dict

  @param fielddefs: Field definitions

  @type selected: list of strings

  @param selected: List of selected fields

  """

  result = []

  for name in selected:

    try:

      fdef = fielddefs[name]

    except KeyError:

      fdef = (_MakeField(name, name, QFT_UNKNOWN), None, _GetUnknownField)

    assert len(fdef) == 3

    result.append(fdef)

  return result

def GetAllFields(fielddefs):

  """Extract L{objects.QueryFieldDefinition} from field definitions.

  @rtype: list of L{objects.QueryFieldDefinition}

  """

  return [fdef for (fdef, _, _) in fielddefs]

class Query:

  def __init__(self, fieldlist, selected):

    """Initializes this class.

    The field definition is a dictionary with the field's name as a key and a

    tuple containing, in order, the field definition object

    (L{objects.QueryFieldDefinition}, the data kind to help calling code

    collect data and a retrieval function. The retrieval function is called

    with two parameters, in order, the data container and the item in container

    (see L{Query.Query}).

    Users of this class can call L{RequestedData} before preparing the data

    container to determine what data is needed.

    @type fieldlist: dictionary

    @param fieldlist: Field definitions

    @type selected: list of strings

    @param selected: List of selected fields

    """

    self._fields = _GetQueryFields(fieldlist, selected)

  def RequestedData(self):

    """Gets requested kinds of data.

    @rtype: frozenset

    """

    return frozenset(datakind

                     for (_, datakind, _) in self._fields

                     if datakind is not None)

  def GetFields(self):

    """Returns the list of fields for this query.

    Includes unknown fields.

    @rtype: List of L{objects.QueryFieldDefinition}

    """

    return GetAllFields(self._fields)

  def Query(self, ctx):

    """Execute a query.

    @param ctx: Data container passed to field retrieval functions, must

      support iteration using C{__iter__}

    """

    result = [[_ProcessResult(fn(ctx, item)) for (_, _, fn) in self._fields]

              for item in ctx]

    # Verify result

    if __debug__:

      for row in result:

        _VerifyResultRow(self._fields, row)

    return result

  def OldStyleQuery(self, ctx):

    """Query with "old" query result format.

    See L{Query.Query} for arguments.

    """

    unknown = set(fdef.name

                  for (fdef, _, _) in self._fields if fdef.kind == QFT_UNKNOWN)

    if unknown:

      raise errors.OpPrereqError("Unknown output fields selected: %s" %

                                 (utils.CommaJoin(unknown), ),

                                 errors.ECODE_INVAL)

    return [[value for (_, value) in row]

            for row in self.Query(ctx)]

def _ProcessResult(value):

  """Converts result values into externally-visible ones.

  """

  if value is _FS_UNKNOWN:

    return (RS_UNKNOWN, None)

  elif value is _FS_NODATA:

    return (RS_NODATA, None)

  elif value is _FS_UNAVAIL:

    return (RS_UNAVAIL, None)

  elif value is _FS_OFFLINE:

    return (RS_OFFLINE, None)

  else:

    return (RS_NORMAL, value)

def _VerifyResultRow(fields, row):

  """Verifies the contents of a query result row.

  @type fields: list

  @param fields: Field definitions for result

  @type row: list of tuples

  @param row: Row data

  """

  assert len(row) == len(fields)

  errs = []

  for ((status, value), (fdef, _, _)) in zip(row, fields):

    if status == RS_NORMAL:

      if not _VERIFY_FN[fdef.kind](value):

        errs.append("normal field %s fails validation (value is %s)" %

                    (fdef.name, value))

    elif value is not None:

      errs.append("abnormal field %s has a non-None value" % fdef.name)

  assert not errs, ("Failed validation: %s in row %s" %

                    (utils.CommaJoin(errors), row))

def _PrepareFieldList(fields, aliases):

  """Prepares field list for use by L{Query}.

  Converts the list to a dictionary and does some verification.

  @type fields: list of tuples; (L{objects.QueryFieldDefinition}, data

      kind, retrieval function)

  @param fields: List of fields, see L{Query.__init__} for a better

      description

  @type aliases: list of tuples; (alias, target)

  @param aliases: list of tuples containing aliases; for each

      alias/target pair, a duplicate will be created in the field list

  @rtype: dict

  @return: Field dictionary for L{Query}

  """

  if __debug__:

    duplicates = utils.FindDuplicates(fdef.title.lower()

                                      for (fdef, _, _) in fields)

    assert not duplicates, "Duplicate title(s) found: %r" % duplicates

  result = {}

  for field in fields:

    (fdef, _, fn) = field

    assert fdef.name and fdef.title, "Name and title are required"

    assert FIELD_NAME_RE.match(fdef.name)

    assert TITLE_RE.match(fdef.title)

    assert callable(fn)

    assert fdef.name not in result, \

           "Duplicate field name '%s' found" % fdef.name

    result[fdef.name] = field

  for alias, target in aliases:

    assert alias not in result, "Alias %s overrides an existing field" % alias

    assert target in result, "Missing target %s for alias %s" % (target, alias)

    (fdef, k, fn) = result[target]

    fdef = fdef.Copy()

    fdef.name = alias

    result[alias] = (fdef, k, fn)

  assert len(result) == len(fields) + len(aliases)

  assert compat.all(name == fdef.name

                    for (name, (fdef, _, _)) in result.items())

  return result

def GetQueryResponse(query, ctx):

  """Prepares the response for a query.

  @type query: L{Query}

  @param ctx: Data container, see L{Query.Query}

  """

  return objects.QueryResponse(data=query.Query(ctx),

                               fields=query.GetFields()).ToDict()

def QueryFields(fielddefs, selected):

  """Returns list of available fields.

  @type fielddefs: dict

  @param fielddefs: Field definitions

  @type selected: list of strings

  @param selected: List of selected fields

  @return: List of L{objects.QueryFieldDefinition}

  """

  if selected is None:

    # Client requests all fields, sort by name

    fdefs = utils.NiceSort(GetAllFields(fielddefs.values()),

                           key=operator.attrgetter("name"))

  else:

    # Keep order as requested by client

    fdefs = Query(fielddefs, selected).GetFields()

  return objects.QueryFieldsResponse(fields=fdefs).ToDict()

def _MakeField(name, title, kind):

  """Wrapper for creating L{objects.QueryFieldDefinition} instances.

  @param name: Field name as a regular expression

  @param title: Human-readable title

  @param kind: Field type

  """

  return objects.QueryFieldDefinition(name=name, title=title, kind=kind)

def _GetNodeRole(node, master_name):

  """Determine node role.

  @type node: L{objects.Node}

  @param node: Node object

  @type master_name: string

  @param master_name: Master node name

  """

  if node.name == master_name:

    return "M"

  elif node.master_candidate:

    return "C"

  elif node.drained:

    return "D"

  elif node.offline:

    return "O"

  else:

    return "R"

def _GetItemAttr(attr):

  """Returns a field function to return an attribute of the item.

  @param attr: Attribute name

  """

  getter = operator.attrgetter(attr)

  return lambda _, item: getter(item)

def _GetItemTimestamp(getter):

  """Returns function for getting timestamp of item.

  @type getter: callable

  @param getter: Function to retrieve timestamp attribute

  """

  def fn(_, item):

    """Returns a timestamp of item.

    """

    timestamp = getter(item)

    if timestamp is None:

      # Old configs might not have all timestamps

      return _FS_UNAVAIL

    else:

      return timestamp

  return fn

def _GetItemTimestampFields(datatype):

  """Returns common timestamp fields.

  @param datatype: Field data type for use by L{Query.RequestedData}

  """

  return [

    (_MakeField("ctime", "CTime", QFT_TIMESTAMP), datatype,

     _GetItemTimestamp(operator.attrgetter("ctime"))),

    (_MakeField("mtime", "MTime", QFT_TIMESTAMP), datatype,

     _GetItemTimestamp(operator.attrgetter("mtime"))),

    ]

class NodeQueryData:

  """Data container for node data queries.

  """

  def __init__(self, nodes, live_data, master_name, node_to_primary,

               node_to_secondary, groups, oob_support, cluster):

    """Initializes this class.

    """

    self.nodes = nodes

    self.live_data = live_data

    self.master_name = master_name

    self.node_to_primary = node_to_primary

    self.node_to_secondary = node_to_secondary

    self.groups = groups

    self.oob_support = oob_support

    self.cluster = cluster

    # Used for individual rows

    self.curlive_data = None

  def __iter__(self):

    """Iterate over all nodes.

    This function has side-effects and only one instance of the resulting

    generator should be used at a time.

    """

    for node in self.nodes:

      if self.live_data:

        self.curlive_data = self.live_data.get(node.name, None)

      else:

        self.curlive_data = None

      yield node

#: Fields that are direct attributes of an L{objects.Node} object

_NODE_SIMPLE_FIELDS = {

  "drained": ("Drained", QFT_BOOL),

  "master_candidate": ("MasterC", QFT_BOOL),

  "master_capable": ("MasterCapable", QFT_BOOL),

  "name": ("Node", QFT_TEXT),

  "offline": ("Offline", QFT_BOOL),

  "serial_no": ("SerialNo", QFT_NUMBER),

  "uuid": ("UUID", QFT_TEXT),

  "vm_capable": ("VMCapable", QFT_BOOL),

  }

#: Fields requiring talking to the node

_NODE_LIVE_FIELDS = {

  "bootid": ("BootID", QFT_TEXT, "bootid"),

  "cnodes": ("CNodes", QFT_NUMBER, "cpu_nodes"),

  "csockets": ("CSockets", QFT_NUMBER, "cpu_sockets"),

  "ctotal": ("CTotal", QFT_NUMBER, "cpu_total"),

  "dfree": ("DFree", QFT_UNIT, "vg_free"),

  "dtotal": ("DTotal", QFT_UNIT, "vg_size"),

  "mfree": ("MFree", QFT_UNIT, "memory_free"),

  "mnode": ("MNode", QFT_UNIT, "memory_dom0"),

  "mtotal": ("MTotal", QFT_UNIT, "memory_total"),

  }

def _GetGroup(cb):

  """Build function for calling another function with an node group.

  @param cb: The callback to be called with the nodegroup

  """

  def fn(ctx, node):

    """Get group data for a node.

    @type ctx: L{NodeQueryData}

    @type inst: L{objects.Node}

    @param inst: Node object

    """

    ng = ctx.groups.get(node.group, None)

    if ng is None:

      # Nodes always have a group, or the configuration is corrupt

      return _FS_UNAVAIL

    return cb(ctx, node, ng)

  return fn

def _GetNodeGroup(ctx, node, ng): # pylint: disable-msg=W0613

  """Returns the name of a node's group.

  @type ctx: L{NodeQueryData}

  @type node: L{objects.Node}

  @param node: Node object

  @type ng: L{objects.NodeGroup}

  @param ng: The node group this node belongs to

  """

  return ng.name

def _GetNodePower(ctx, node):

  """Returns the node powered state

  @type ctx: L{NodeQueryData}

  @type node: L{objects.Node}

  @param node: Node object

  """

  if ctx.oob_support[node.name]:

    return node.powered

  return _FS_UNAVAIL

def _GetNdParams(ctx, node, ng):

  """Returns the ndparams for this node.

  @type ctx: L{NodeQueryData}

  @type node: L{objects.Node}

  @param node: Node object

  @type ng: L{objects.NodeGroup}

  @param ng: The node group this node belongs to

  """

  return ctx.cluster.SimpleFillND(ng.FillND(node))

def _GetLiveNodeField(field, kind, ctx, node):

  """Gets the value of a "live" field from L{NodeQueryData}.

  @param field: Live field name

  @param kind: Data kind, one of L{constants.QFT_ALL}

  @type ctx: L{NodeQueryData}

  @type node: L{objects.Node}

  @param node: Node object

  """

  if node.offline:

    return _FS_OFFLINE

  if not ctx.curlive_data:

    return _FS_NODATA

  try:

    value = ctx.curlive_data[field]

  except KeyError:

    return _FS_UNAVAIL

  if kind == QFT_TEXT:

    return value

  assert kind in (QFT_NUMBER, QFT_UNIT)

  # Try to convert into number

  try:

    return int(value)

  except (ValueError, TypeError):

    logging.exception("Failed to convert node field '%s' (value %r) to int",

                      value, field)

    return _FS_UNAVAIL

def _BuildNodeFields():

  """Builds list of fields for node queries.

  """

  fields = [

    (_MakeField("pip", "PrimaryIP", QFT_TEXT), NQ_CONFIG,

     _GetItemAttr("primary_ip")),

    (_MakeField("sip", "SecondaryIP", QFT_TEXT), NQ_CONFIG,

     _GetItemAttr("secondary_ip")),

    (_MakeField("tags", "Tags", QFT_OTHER), NQ_CONFIG,

     lambda ctx, node: list(node.GetTags())),

    (_MakeField("master", "IsMaster", QFT_BOOL), NQ_CONFIG,

     lambda ctx, node: node.name == ctx.master_name),

    (_MakeField("role", "Role", QFT_TEXT), NQ_CONFIG,

     lambda ctx, node: _GetNodeRole(node, ctx.master_name)),

    (_MakeField("group", "Group", QFT_TEXT), NQ_GROUP,

     _GetGroup(_GetNodeGroup)),

    (_MakeField("group.uuid", "GroupUUID", QFT_TEXT),

     NQ_CONFIG, _GetItemAttr("group")),

    (_MakeField("powered", "Powered", QFT_BOOL), NQ_OOB, _GetNodePower),

    (_MakeField("ndparams", "NodeParameters", QFT_OTHER), NQ_GROUP,

      _GetGroup(_GetNdParams)),

    (_MakeField("custom_ndparams", "CustomNodeParameters", QFT_OTHER),

      NQ_GROUP, _GetItemAttr("ndparams")),

    ]

  def _GetLength(getter):

    return lambda ctx, node: len(getter(ctx)[node.name])

  def _GetList(getter):

    return lambda ctx, node: list(getter(ctx)[node.name])

  # Add fields operating on instance lists

  for prefix, titleprefix, getter in \

      [("p", "Pri", operator.attrgetter("node_to_primary")),

       ("s", "Sec", operator.attrgetter("node_to_secondary"))]:

    fields.extend([

      (_MakeField("%sinst_cnt" % prefix, "%sinst" % prefix.upper(), QFT_NUMBER),

       NQ_INST, _GetLength(getter)),

      (_MakeField("%sinst_list" % prefix, "%sInstances" % titleprefix,

                  QFT_OTHER),

       NQ_INST, _GetList(getter)),

      ])

  # Add simple fields

  fields.extend([(_MakeField(name, title, kind), NQ_CONFIG, _GetItemAttr(name))

                 for (name, (title, kind)) in _NODE_SIMPLE_FIELDS.items()])

  # Add fields requiring live data

  fields.extend([

    (_MakeField(name, title, kind), NQ_LIVE,

     compat.partial(_GetLiveNodeField, nfield, kind))

    for (name, (title, kind, nfield)) in _NODE_LIVE_FIELDS.items()

    ])

  # Add timestamps

  fields.extend(_GetItemTimestampFields(NQ_CONFIG))

  return _PrepareFieldList(fields, [])

class InstanceQueryData:

  """Data container for instance data queries.

  """

  def __init__(self, instances, cluster, disk_usage, offline_nodes, bad_nodes,

               live_data):

    """Initializes this class.

    @param instances: List of instance objects

    @param cluster: Cluster object

    @type disk_usage: dict; instance name as key

    @param disk_usage: Per-instance disk usage

    @type offline_nodes: list of strings

    @param offline_nodes: List of offline nodes

    @type bad_nodes: list of strings

    @param bad_nodes: List of faulty nodes

    @type live_data: dict; instance name as key

    @param live_data: Per-instance live data

    """

    assert len(set(bad_nodes) & set(offline_nodes)) == len(offline_nodes), \

           "Offline nodes not included in bad nodes"

    assert not (set(live_data.keys()) & set(bad_nodes)), \

           "Found live data for bad or offline nodes"

    self.instances = instances

    self.cluster = cluster

    self.disk_usage = disk_usage

    self.offline_nodes = offline_nodes

    self.bad_nodes = bad_nodes

    self.live_data = live_data

    # Used for individual rows

    self.inst_hvparams = None

    self.inst_beparams = None

    self.inst_nicparams = None

  def __iter__(self):

    """Iterate over all instances.

    This function has side-effects and only one instance of the resulting

    generator should be used at a time.

    """

    for inst in self.instances:

      self.inst_hvparams = self.cluster.FillHV(inst, skip_globals=True)

      self.inst_beparams = self.cluster.FillBE(inst)

      self.inst_nicparams = [self.cluster.SimpleFillNIC(nic.nicparams)

                             for nic in inst.nics]

      yield inst

def _GetInstOperState(ctx, inst):

  """Get instance's operational status.

  @type ctx: L{InstanceQueryData}

  @type inst: L{objects.Instance}

  @param inst: Instance object

  """

  # Can't use RS_OFFLINE here as it would describe the instance to

  # be offline when we actually don't know due to missing data

  if inst.primary_node in ctx.bad_nodes:

    return _FS_NODATA

  else:

    return bool(ctx.live_data.get(inst.name))

def _GetInstLiveData(name):

  """Build function for retrieving live data.

  @type name: string

  @param name: Live data field name

  """