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#

#

# Copyright (C) 2006, 2007, 2008 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.

"""Remote API base resources library.

"""

# pylint: disable-msg=C0103

# C0103: Invalid name, since the R_* names are not conforming

import logging

from ganeti import luxi

from ganeti import rapi

from ganeti import http

from ganeti import ssconf

from ganeti import constants

from ganeti import opcodes

from ganeti import errors

# Dummy value to detect unchanged parameters

_DEFAULT = object()

def BuildUriList(ids, uri_format, uri_fields=("name", "uri")):

  """Builds a URI list as used by index resources.

  @param ids: list of ids as strings

  @param uri_format: format to be applied for URI

  @param uri_fields: optional parameter for field IDs

  """

  (field_id, field_uri) = uri_fields

  def _MapId(m_id):

    return { field_id: m_id, field_uri: uri_format % m_id, }

  # Make sure the result is sorted, makes it nicer to look at and simplifies

  # unittests.

  ids.sort()

  return map(_MapId, ids)

def ExtractField(sequence, index):

  """Creates a list containing one column out of a list of lists.

  @param sequence: sequence of lists

  @param index: index of field

  """

  return map(lambda item: item[index], sequence)

def MapFields(names, data):

  """Maps two lists into one dictionary.

  Example::

      >>> MapFields(["a", "b"], ["foo", 123])

      {'a': 'foo', 'b': 123}

  @param names: field names (list of strings)

  @param data: field data (list)

  """

  if len(names) != len(data):

    raise AttributeError("Names and data must have the same length")

  return dict(zip(names, data))

def _Tags_GET(kind, name):

  """Helper function to retrieve tags.

  """

  if kind == constants.TAG_INSTANCE or kind == constants.TAG_NODE:

    if not name:

      raise http.HttpBadRequest("Missing name on tag request")

    cl = GetClient()

    if kind == constants.TAG_INSTANCE:

      fn = cl.QueryInstances

    else:

      fn = cl.QueryNodes

    result = fn(names=[name], fields=["tags"], use_locking=False)

    if not result or not result[0]:

      raise http.HttpBadGateway("Invalid response from tag query")

    tags = result[0][0]

  elif kind == constants.TAG_CLUSTER:

    ssc = ssconf.SimpleStore()

    tags = ssc.GetClusterTags()

  return list(tags)

def _Tags_PUT(kind, tags, name, dry_run):

  """Helper function to set tags.

  """

  return SubmitJob([opcodes.OpAddTags(kind=kind, name=name,

                                      tags=tags, dry_run=dry_run)])

def _Tags_DELETE(kind, tags, name, dry_run):

  """Helper function to delete tags.

  """

  return SubmitJob([opcodes.OpDelTags(kind=kind, name=name,

                                      tags=tags, dry_run=dry_run)])

def MapBulkFields(itemslist, fields):

  """Map value to field name in to one dictionary.

  @param itemslist: a list of items values

  @param fields: a list of items names

  @return: a list of mapped dictionaries

  """

  items_details = []

  for item in itemslist:

    mapped = MapFields(fields, item)

    items_details.append(mapped)

  return items_details

def MakeParamsDict(opts, params):

  """Makes params dictionary out of a option set.

  This function returns a dictionary needed for hv or be parameters. But only

  those fields which provided in the option set. Takes parameters frozensets

  from constants.

  @type opts: dict

  @param opts: selected options

  @type params: frozenset

  @param params: subset of options

  @rtype: dict

  @return: dictionary of options, filtered by given subset.

  """

  result = {}

  for p in params:

    try:

      value = opts[p]

    except KeyError:

      continue

    result[p] = value

  return result

def SubmitJob(op, cl=None):

  """Generic wrapper for submit job, for better http compatibility.

  @type op: list

  @param op: the list of opcodes for the job

  @type cl: None or luxi.Client

  @param cl: optional luxi client to use

  @rtype: string

  @return: the job ID

  """

  try:

    if cl is None:

      cl = GetClient()

    return cl.SubmitJob(op)

  except errors.JobQueueFull:

    raise http.HttpServiceUnavailable("Job queue is full, needs archiving")

  except errors.JobQueueDrainError:

    raise http.HttpServiceUnavailable("Job queue is drained, cannot submit")

  except luxi.NoMasterError, err:

    raise http.HttpBadGateway("Master seems to unreachable: %s" % str(err))

  except luxi.TimeoutError, err:

    raise http.HttpGatewayTimeout("Timeout while talking to the master"

                                  " daemon. Error: %s" % str(err))

def HandleItemQueryErrors(fn, *args, **kwargs):

  """Converts errors when querying a single item.

  """

  try:

    return fn(*args, **kwargs)

  except errors.OpPrereqError, err:

    if len(err.args) == 2 and err.args[1] == errors.ECODE_NOENT:

      raise http.HttpNotFound()

    raise

def GetClient():

  """Geric wrapper for luxi.Client(), for better http compatiblity.

  """

  try:

    return luxi.Client()

  except luxi.NoMasterError, err:

    raise http.HttpBadGateway("Master seems to unreachable: %s" % str(err))

def FeedbackFn(msg):

  """Feedback logging function for jobs.

  We don't have a stdout for printing log messages, so log them to the

  http log at least.

  @param msg: the message

  """

  (_, log_type, log_msg) = msg

  logging.info("%s: %s", log_type, log_msg)

def CheckType(value, exptype, descr):

  """Abort request if value type doesn't match expected type.

  @param value: Value

  @type exptype: type

  @param exptype: Expected type

  @type descr: string

  @param descr: Description of value

  @return: Value (allows inline usage)

  """

  if not isinstance(value, exptype):

    raise http.HttpBadRequest("%s: Type is '%s', but '%s' is expected" %

                              (descr, type(value).__name__, exptype.__name__))

  return value

def CheckParameter(data, name, default=_DEFAULT, exptype=_DEFAULT):

  """Check and return the value for a given parameter.

  If no default value was given and the parameter doesn't exist in the input

  data, an error is raise.

  @type data: dict

  @param data: Dictionary containing input data

  @type name: string

  @param name: Parameter name

  @param default: Default value (can be None)

  @param exptype: Expected type (can be None)

  """

  try:

    value = data[name]

  except KeyError:

    if default is not _DEFAULT:

      return default

    raise http.HttpBadRequest("Required parameter '%s' is missing" %

                              name)

  if exptype is _DEFAULT:

    return value

  return CheckType(value, exptype, "'%s' parameter" % name)

class R_Generic(object):

  """Generic class for resources.

  """

  # Default permission requirements

  GET_ACCESS = []

  PUT_ACCESS = [rapi.RAPI_ACCESS_WRITE]

  POST_ACCESS = [rapi.RAPI_ACCESS_WRITE]

  DELETE_ACCESS = [rapi.RAPI_ACCESS_WRITE]

  def __init__(self, items, queryargs, req):

    """Generic resource constructor.

    @param items: a list with variables encoded in the URL

    @param queryargs: a dictionary with additional options from URL

    """

    self.items = items

    self.queryargs = queryargs

    self._req = req

  def _GetRequestBody(self):

    """Returns the body data.

    """

    return self._req.private.body_data

  request_body = property(fget=_GetRequestBody)

  def _checkIntVariable(self, name, default=0):

    """Return the parsed value of an int argument.

    """

    val = self.queryargs.get(name, default)

    if isinstance(val, list):

      if val:

        val = val[0]

      else:

        val = default

    try:

      val = int(val)

    except (ValueError, TypeError):

      raise http.HttpBadRequest("Invalid value for the"

                                " '%s' parameter" % (name,))

    return val

  def _checkStringVariable(self, name, default=None):

    """Return the parsed value of an int argument.

    """

    val = self.queryargs.get(name, default)

    if isinstance(val, list):

      if val:

        val = val[0]

      else:

        val = default

    return val

  def getBodyParameter(self, name, *args):

    """Check and return the value for a given parameter.

    If a second parameter is not given, an error will be returned,

    otherwise this parameter specifies the default value.

    @param name: the required parameter

    """

    if args:

      return CheckParameter(self.request_body, name, default=args[0])

    return CheckParameter(self.request_body, name)

  def useLocking(self):

    """Check if the request specifies locking.

    """

    return bool(self._checkIntVariable("lock"))

  def useBulk(self):

    """Check if the request specifies bulk querying.

    """

    return bool(self._checkIntVariable("bulk"))

  def useForce(self):

    """Check if the request specifies a forced operation.

    """

    return bool(self._checkIntVariable("force"))

  def dryRun(self):

    """Check if the request specifies dry-run mode.

    """

    return bool(self._checkIntVariable("dry-run"))