Synnefo » snf-ganeti

	qa/qa_utils.py \

        qa/rapi-workload.py

#!/usr/bin/python -u

#

# Copyright (C) 2013 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.

#

# 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.

"""Script for providing a large amount of RAPI calls to Ganeti.

"""

# pylint: disable=C0103

# due to invalid name

import sys

from ganeti.rapi.client import GanetiApiError

import qa_config

import qa_node

import qa_rapi

# The purpose of this file is to provide a stable and extensive RAPI workload

# that manipulates the cluster only using RAPI commands, with the assumption

# that an empty cluster was set up beforehand. All the nodes that can be added

# to the cluster should be a part of it, and no instances should be present.

#

# Its intended use is in RAPI compatibility tests, where different versions with

# possibly vastly different QAs must be compared. Running the QA on both

# versions of the cluster will produce RAPI calls, but there is no guarantee

# that they will match, or that functions invoked in between will not change the

# results.

#

# By using only RAPI functions, we are sure to be able to capture and log all

# the changes in cluster state, and be able to compare them afterwards.

#

# The functionality of the QA is still used to generate a functioning,

# RAPI-enabled cluster, and to set up a C{GanetiRapiClient} capable of issuing

# commands to the cluster.

#

# Due to the fact that not all calls issued as a part of the workload might be

# implemented in the different versions of Ganeti, the client does not halt or

# produce a non-zero exit code upon encountering a RAPI error. Instead, it

# reports it and moves on. Any utility comparing the requests should account for

# this.

def MockMethod(*_args, **_kwargs):

  """ Absorbs all arguments, does nothing, returns None.

  """

  return None

def InvokerCreator(fn, name):

  """ Returns an invoker function that will invoke the given function

  with any arguments passed to the invoker at a later time, while

  catching any specific non-fatal errors we would like to know more

  about.

  @type fn arbitrary function

  @param fn The function to invoke later.

  @type name string

  @param name The name of the function, for debugging purposes.

  @rtype function

  """

  def decoratedFn(*args, **kwargs):

    result = None

    try:

      print "Using method %s" % name

      result = fn(*args, **kwargs)

    except GanetiApiError as e:

      print "RAPI error while performing function %s : %s" % \

            (name, str(e))

    return result

  return decoratedFn

RAPI_USERNAME = "ganeti-qa"

class GanetiRapiClientWrapper(object):

  """ Creates and initializes a GanetiRapiClient, and acts as a wrapper invoking

  only the methods that the version of the client actually uses.

  """

  def __init__(self):

    self._client = qa_rapi.Setup(RAPI_USERNAME,

                                 qa_rapi.LookupRapiSecret(RAPI_USERNAME))

  def __getattr__(self, attr):

    """ Fetches an attribute from the underlying client if necessary.

    """

    # Assuming that this method exposes no public methods of its own,

    # and that any private methods are named according to the style

    # guide, this will stop infinite loops in attribute fetches.

    if attr.startswith("_"):

      return self.__getattribute__(attr)

    try:

      return InvokerCreator(self._client.__getattribute__(attr), attr)

    except AttributeError:

      print "Missing method %s; supplying mock method" % attr

      return MockMethod

def Workload(client):

  """ The actual RAPI workload used for tests.

  @type client C{GanetiRapiClientWrapper}

  @param client A wrapped RAPI client.

  """

  print client.GetVersion()

def Usage():

  sys.stderr.write("Usage:\n\trapi-workload.py qa-config-file")

def Main():

  if len(sys.argv) < 2:

    Usage()

  qa_config.Load(sys.argv[1])

  # Only the master will be present after a fresh QA cluster setup, so we have

  # to invoke this to get all the other nodes.

  qa_node.TestNodeAddAll()

  client = GanetiRapiClientWrapper()

  Workload(client)

  qa_node.TestNodeRemoveAll()

if __name__ == "__main__":

  Main()