Synnefo » snf-ganeti

#

#

# Copyright (C) 2010 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.

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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"""

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

(NQ_CONFIG,

 NQ_INST,

 NQ_LIVE,

 NQ_GROUP) = range(1, 5)

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

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

#: Verification function for each field type

_VERIFY_FN = {

  constants.QFT_UNKNOWN: ht.TNone,

  constants.QFT_TEXT: ht.TString,

  constants.QFT_BOOL: ht.TBool,

  constants.QFT_NUMBER: ht.TInt,

  constants.QFT_UNIT: ht.TInt,

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

  constants.QFT_OTHER: lambda _: True,

  }

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

  """Gets the contents of an unknown field.

  """

  return (constants.QRFS_UNKNOWN, None)

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

              for item in ctx]

    # Verify result

    if __debug__:

      for (idx, row) in enumerate(result):

        assert _VerifyResultRow(self._fields, row), \

               ("Inconsistent result for fields %s in row %s: %r" %

                (GetAllFields(self._fields), idx, 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 == constants.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 _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

  """

  return (len(row) == len(fields) and

          compat.all((status == constants.QRFS_NORMAL and

                      _VERIFY_FN[fdef.kind](value)) or

                     # Value for an abnormal status must be None

                     (status != constants.QRFS_NORMAL and value is None)

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

def _PrepareFieldList(fields):

  """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

  @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

  assert len(result) == len(fields)

  assert compat.all(name == fdef.name

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

  return result

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: (constants.QRFS_NORMAL, getter(item))

class NodeQueryData:

  """Data container for node data queries.

  """

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

               node_to_secondary, groups):

    """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

    # 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 = {

  "ctime": ("CTime", constants.QFT_TIMESTAMP),

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

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

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

  "mtime": ("MTime", constants.QFT_TIMESTAMP),

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

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

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

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

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

  }

#: Fields requiring talking to the node

_NODE_LIVE_FIELDS = {

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

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

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

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

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

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

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

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

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

  }

def _GetNodeGroup(ctx, node):

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

  @type ctx: L{NodeQueryData}

  @type node: L{objects.Node}

  @param node: Node object

  """

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

  if ng is None:

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

    return (constants.QRFS_UNAVAIL, None)

  return (constants.QRFS_NORMAL, ng.name)

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

  """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}

  """

  if not ctx.curlive_data:

    return (constants.QRFS_NODATA, None)

  try:

    value = ctx.curlive_data[field]

  except KeyError:

    return (constants.QRFS_UNAVAIL, None)

  if kind == constants.QFT_TEXT:

    return (constants.QRFS_NORMAL, value)

  assert kind in (constants.QFT_NUMBER, constants.QFT_UNIT)

  # Try to convert into number

  try:

    return (constants.QRFS_NORMAL, int(value))

  except (ValueError, TypeError):

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

                      value, field)

    return (constants.QRFS_UNAVAIL, None)

def _BuildNodeFields():

  """Builds list of fields for node queries.

  """

  fields = [

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

     lambda ctx, node: (constants.QRFS_NORMAL, node.primary_ip)),

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

     lambda ctx, node: (constants.QRFS_NORMAL, node.secondary_ip)),

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

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

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

     lambda ctx, node: (constants.QRFS_NORMAL, node.name == ctx.master_name)),

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

     lambda ctx, node: (constants.QRFS_NORMAL,

                        _GetNodeRole(node, ctx.master_name))),

    (_MakeField("group", "Group", constants.QFT_TEXT), NQ_GROUP, _GetNodeGroup),

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

     NQ_CONFIG, lambda ctx, node: (constants.QRFS_NORMAL, node.group)),

    ]

  def _GetLength(getter):

    return lambda ctx, node: (constants.QRFS_NORMAL,

                              len(getter(ctx)[node.name]))

  def _GetList(getter):

    return lambda ctx, node: (constants.QRFS_NORMAL,

                              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(),

                  constants.QFT_NUMBER),

       NQ_INST, _GetLength(getter)),

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

                  constants.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()

    ])

  return _PrepareFieldList(fields)

#: Fields available for node queries

NODE_FIELDS = _BuildNodeFields()