src/nepi/core/execute.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 from nepi.core.attributes import Attribute, AttributesMap
   5 from nepi.core.connector import ConnectorTypeBase
   6 from nepi.util import proxy, validation
   7 from nepi.util.constants import STATUS_FINISHED, TIME_NOW
   8 from nepi.util.parser._xml import XmlExperimentParser
   9 import sys
  10 import re
  11 import threading
  12 import ConfigParser
  13 import os
  14
  15 ATTRIBUTE_PATTERN_BASE = re.compile(r"\{#\[(?P<label>[-a-zA-Z0-9._]*)\](?P<expr>(?P<component>\.addr\[[0-9]+\]|\.route\[[0-9]+\]|\.trace\[[0-9]+\]|).\[(?P<attribute>[-a-zA-Z0-9._]*)\])#}")
  16 ATTRIBUTE_PATTERN_GUID_SUB = r"{#[%(guid)s]%(expr)s#}"
  17 COMPONENT_PATTERN = re.compile(r"(?P<kind>[a-z]*)\[(?P<index>.*)\]")
  18
  19 class ConnectorType(ConnectorTypeBase):
  20     def __init__(self, testbed_id, factory_id, name, max = -1, min = 0):
  21         super(ConnectorType, self).__init__(testbed_id, factory_id, name, max, min)
  22         # from_connections -- connections where the other connector is the "From"
  23         # to_connections -- connections where the other connector is the "To"
  24         # keys in the dictionary correspond to the
  25         # connector_type_id for possible connections. The value is a tuple:
  26         # (can_cross, connect)
  27         # can_cross: indicates if the connection is allowed accros different
  28         #    testbed instances
  29         # code: is the connection function to be invoked when the elements
  30         #    are connected
  31         self._from_connections = dict()
  32         self._to_connections = dict()
  33
  34     def add_from_connection(self, testbed_id, factory_id, name, can_cross,
  35             init_code, compl_code):
  36         type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  37         self._from_connections[type_id] = (can_cross, init_code, compl_code)
  38
  39     def add_to_connection(self, testbed_id, factory_id, name, can_cross,
  40             init_code, compl_code):
  41         type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  42         self._to_connections[type_id] = (can_cross, init_code, compl_code)
  43
  44     def can_connect(self, testbed_id, factory_id, name, count,
  45             must_cross = False):
  46         connector_type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  47         for lookup_type_id in self._type_resolution_order(connector_type_id):
  48             if lookup_type_id in self._from_connections:
  49                 (can_cross, init_code, compl_code) = self._from_connections[lookup_type_id]
  50             elif lookup_type_id in self._to_connections:
  51                 (can_cross, init_code, compl_code) = self._to_connections[lookup_type_id]
  52             else:
  53                 # keey trying
  54                 continue
  55             return not must_cross or can_cross
  56         else:
  57             return False
  58
  59     def _connect_to_code(self, testbed_id, factory_id, name):
  60         connector_type_id = self.make_connector_type_id(testbed_id, factory_id, name)
  61         for lookup_type_id in self._type_resolution_order(connector_type_id):
  62             if lookup_type_id in self._to_connections:
  63                 (can_cross, init_code, compl_code) = self._to_connections[lookup_type_id]
  64                 return (init_code, compl_code)
  65         else:
  66             return (False, False)
  67
  68     def connect_to_init_code(self, testbed_id, factory_id, name):
  69         return self._connect_to_code(testbed_id, factory_id, name)[0]
  70
  71     def connect_to_compl_code(self, testbed_id, factory_id, name):
  72         return self._connect_to_code(testbed_id, factory_id, name)[1]
  73
  74 class Factory(AttributesMap):
  75     def __init__(self, factory_id, create_function, start_function,
  76             stop_function, status_function,
  77             configure_function, preconfigure_function,
  78             allow_addresses = False, has_addresses = False,
  79             allow_routes = False, has_routes = False):
  80         super(Factory, self).__init__()
  81         self._factory_id = factory_id
  82         self._allow_addresses = bool(allow_addresses)
  83         self._allow_routes = bool(allow_routes)
  84         self._has_addresses = bool(has_addresses) or self._allow_addresses
  85         self._has_routes = bool(has_routes) or self._allow_routes
  86         self._create_function = create_function
  87         self._start_function = start_function
  88         self._stop_function = stop_function
  89         self._status_function = status_function
  90         self._configure_function = configure_function
  91         self._preconfigure_function = preconfigure_function
  92         self._connector_types = dict()
  93         self._traces = list()
  94         self._box_attributes = AttributesMap()
  95
  96     @property
  97     def factory_id(self):
  98         return self._factory_id
  99
 100     @property
 101     def allow_addresses(self):
 102         return self._allow_addresses
 103
 104     @property
 105     def allow_routes(self):
 106         return self._allow_routes
 107
 108     @property
 109     def has_addresses(self):
 110         return self._has_addresses
 111
 112     @property
 113     def has_routes(self):
 114         return self._has_routes
 115
 116     @property
 117     def box_attributes(self):
 118         return self._box_attributes
 119
 120     @property
 121     def create_function(self):
 122         return self._create_function
 123
 124     @property
 125     def start_function(self):
 126         return self._start_function
 127
 128     @property
 129     def stop_function(self):
 130         return self._stop_function
 131
 132     @property
 133     def status_function(self):
 134         return self._status_function
 135
 136     @property
 137     def configure_function(self):
 138         return self._configure_function
 139
 140     @property
 141     def preconfigure_function(self):
 142         return self._preconfigure_function
 143
 144     @property
 145     def traces(self):
 146         return self._traces
 147
 148     def connector_type(self, name):
 149         return self._connector_types[name]
 150
 151     def add_connector_type(self, connector_type):
 152         self._connector_types[connector_type.name] = connector_type
 153
 154     def add_trace(self, trace_id):
 155         self._traces.append(trace_id)
 156
 157     def add_box_attribute(self, name, help, type, value = None, range = None,
 158         allowed = None, flags = Attribute.NoFlags, validation_function = None):
 159         self._box_attributes.add_attribute(name, help, type, value, range,
 160                 allowed, flags, validation_function)
 161
 162 class TestbedController(object):
 163     def __init__(self, testbed_id, testbed_version):
 164         self._testbed_id = testbed_id
 165         self._testbed_version = testbed_version
 166
 167     @property
 168     def testbed_id(self):
 169         return self._testbed_id
 170
 171     @property
 172     def testbed_version(self):
 173         return self._testbed_version
 174
 175     @property
 176     def guids(self):
 177         raise NotImplementedError
 178
 179     def defer_configure(self, name, value):
 180         """Instructs setting a configuartion attribute for the testbed instance"""
 181         raise NotImplementedError
 182
 183     def defer_create(self, guid, factory_id):
 184         """Instructs creation of element """
 185         raise NotImplementedError
 186
 187     def defer_create_set(self, guid, name, value):
 188         """Instructs setting an initial attribute on an element"""
 189         raise NotImplementedError
 190
 191     def defer_factory_set(self, guid, name, value):
 192         """Instructs setting an attribute on a factory"""
 193         raise NotImplementedError
 194
 195     def defer_connect(self, guid1, connector_type_name1, guid2,
 196             connector_type_name2):
 197         """Instructs creation of a connection between the given connectors"""
 198         raise NotImplementedError
 199
 200     def defer_cross_connect(self, guid, connector_type_name, cross_guid,
 201             cross_testbed_id, cross_factory_id, cross_connector_type_name):
 202         """
 203         Instructs creation of a connection between the given connectors
 204         of different testbed instances
 205         """
 206         raise NotImplementedError
 207
 208     def defer_add_trace(self, guid, trace_id):
 209         """Instructs the addition of a trace"""
 210         raise NotImplementedError
 211
 212     def defer_add_address(self, guid, address, netprefix, broadcast):
 213         """Instructs the addition of an address"""
 214         raise NotImplementedError
 215
 216     def defer_add_route(self, guid, destination, netprefix, nexthop):
 217         """Instructs the addition of a route"""
 218         raise NotImplementedError
 219
 220     def do_setup(self):
 221         """After do_setup the testbed initial configuration is done"""
 222         raise NotImplementedError
 223
 224     def do_create(self):
 225         """
 226         After do_create all instructed elements are created and
 227         attributes setted
 228         """
 229         raise NotImplementedError
 230
 231     def do_connect_init(self):
 232         """
 233         After do_connect_init all internal connections between testbed elements
 234         are initiated
 235         """
 236         raise NotImplementedError
 237
 238     def do_connect_compl(self):
 239         """
 240         After do_connect all internal connections between testbed elements
 241         are completed
 242         """
 243         raise NotImplementedError
 244
 245     def do_configure(self):
 246         """After do_configure elements are configured"""
 247         raise NotImplementedError
 248
 249     def do_cross_connect_init(self, cross_data):
 250         """
 251         After do_cross_connect_init initiation of all external connections
 252         between different testbed elements is performed
 253         """
 254         raise NotImplementedError
 255
 256     def do_cross_connect_compl(self, cross_data):
 257         """
 258         After do_cross_connect_compl completion of all external connections
 259         between different testbed elements is performed
 260         """
 261         raise NotImplementedError
 262
 263     def start(self):
 264         raise NotImplementedError
 265
 266     def stop(self):
 267         raise NotImplementedError
 268
 269     def set(self, guid, name, value, time = TIME_NOW):
 270         raise NotImplementedError
 271
 272     def get(self, guid, name, time = TIME_NOW):
 273         raise NotImplementedError
 274
 275     def get_route(self, guid, index, attribute):
 276         """
 277         Params:
 278
 279             guid: guid of box to query
 280             index: number of routing entry to fetch
 281             attribute: one of Destination, NextHop, NetPrefix
 282         """
 283         raise NotImplementedError
 284
 285     def get_address(self, guid, index, attribute='Address'):
 286         """
 287         Params:
 288
 289             guid: guid of box to query
 290             index: number of inteface to select
 291             attribute: one of Address, NetPrefix, Broadcast
 292         """
 293         raise NotImplementedError
 294
 295     def get_attribute_list(self, guid):
 296         raise NotImplementedError
 297
 298     def action(self, time, guid, action):
 299         raise NotImplementedError
 300
 301     def status(self, guid):
 302         raise NotImplementedError
 303
 304     def trace(self, guid, trace_id, attribute='value'):
 305         raise NotImplementedError
 306
 307     def shutdown(self):
 308         raise NotImplementedError
 309
 310 class ExperimentController(object):
 311     def __init__(self, experiment_xml, root_dir):
 312         self._experiment_xml = experiment_xml
 313         self._testbeds = dict()
 314         self._deployment_config = dict()
 315         self._netrefs = dict()
 316         self._cross_data = dict()
 317         self._root_dir = root_dir
 318
 319         self.persist_experiment_xml()
 320
 321     @property
 322     def experiment_xml(self):
 323         return self._experiment_xml
 324
 325     def persist_experiment_xml(self):
 326         xml_path = os.path.join(self._root_dir, "experiment.xml")
 327         f = open(xml_path, "w")
 328         f.write(self._experiment_xml)
 329         f.close()
 330
 331     def trace(self, testbed_guid, guid, trace_id, attribute='value'):
 332         return self._testbeds[testbed_guid].trace(guid, trace_id, attribute)
 333
 334     @staticmethod
 335     def _parallel(callables):
 336         threads = [ threading.Thread(target=callable) for callable in callables ]
 337         for thread in threads:
 338             thread.start()
 339         for thread in threads:
 340             thread.join()
 341
 342     def start(self):
 343         self._init_testbed_controllers()
 344
 345         # persist testbed connection data, for potential recovery
 346         self._persist_testbed_proxies()
 347
 348         # perform setup in parallel for all test beds,
 349         # wait for all threads to finish
 350         self._parallel([testbed.do_setup
 351                         for testbed in self._testbeds.itervalues()])
 352
 353         # perform create-connect in parallel, wait
 354         # (internal connections only)
 355         self._parallel([testbed.do_create
 356                         for testbed in self._testbeds.itervalues()])
 357
 358         self._parallel([testbed.do_connect_init
 359                         for testbed in self._testbeds.itervalues()])
 360
 361         self._parallel([testbed.do_connect_compl
 362                         for testbed in self._testbeds.itervalues()])
 363
 364         self._parallel([testbed.do_preconfigure
 365                         for testbed in self._testbeds.itervalues()])
 366
 367         # resolve netrefs
 368         self.do_netrefs(fail_if_undefined=True)
 369
 370         # perform do_configure in parallel for al testbeds
 371         # (it's internal configuration for each)
 372         self._parallel([testbed.do_configure
 373                         for testbed in self._testbeds.itervalues()])
 374
 375         # cross-connect (cannot be done in parallel)
 376         for guid, testbed in self._testbeds.iteritems():
 377             cross_data = self._get_cross_data(guid)
 378             testbed.do_cross_connect_init(cross_data)
 379         for guid, testbed in self._testbeds.iteritems():
 380             cross_data = self._get_cross_data(guid)
 381             testbed.do_cross_connect_compl(cross_data)
 382
 383         # start experiment (parallel start on all testbeds)
 384         self._parallel([testbed.start
 385                         for testbed in self._testbeds.itervalues()])
 386
 387     def _persist_testbed_proxies(self):
 388         TRANSIENT = ('Recover',)
 389
 390         # persist access configuration for all testbeds, so that
 391         # recovery mode can reconnect to them if it becomes necessary
 392         conf = ConfigParser.RawConfigParser()
 393         for testbed_guid, testbed_config in self._deployment_config.iteritems():
 394             testbed_guid = str(testbed_guid)
 395             conf.add_section(testbed_guid)
 396             for attr in testbed_config.attributes_list:
 397                 if attr not in TRANSIENT:
 398                     conf.set(testbed_guid, attr,
 399                         testbed_config.get_attribute_value(attr))
 400
 401         f = open(os.path.join(self._root_dir, 'deployment_config.ini'), 'w')
 402         conf.write(f)
 403         f.close()
 404
 405     def _load_testbed_proxies(self):
 406         TYPEMAP = {
 407             STRING : 'get',
 408             INTEGER : 'getint',
 409             FLOAT : 'getfloat',
 410             BOOLEAN : 'getboolean',
 411         }
 412
 413         conf = ConfigParser.RawConfigParser()
 414         conf.read(os.path.join(self._root_dir, 'deployment_config.ini'))
 415         for testbed_guid in conf.sections():
 416             testbed_config = proxy.AccessConfiguration()
 417             for attr in conf.options(testbed_guid):
 418                 testbed_config.set_attribute_value(attr,
 419                     conf.get(testbed_guid, attr) )
 420
 421             testbed_guid = str(testbed_guid)
 422             conf.add_section(testbed_guid)
 423             for attr in testbed_config.attributes_list:
 424                 if attr not in TRANSIENT:
 425                     getter = getattr(conf, TYPEMAP.get(
 426                         testbed_config.get_attribute_type(attr),
 427                         'get') )
 428                     testbed_config.set_attribute_value(
 429                         testbed_guid, attr, getter(attr))
 430
 431     def _unpersist_testbed_proxies(self):
 432         try:
 433             os.remove(os.path.join(self._root_dir, 'deployment_config.ini'))
 434         except:
 435             # Just print exceptions, this is just cleanup
 436             import traceback
 437             traceback.print_exc(file=sys.stderr)
 438
 439     def stop(self):
 440        for testbed in self._testbeds.values():
 441            testbed.stop()
 442        self._unpersist_testbed_proxies()
 443
 444     def recover(self):
 445         # reload perviously persisted testbed access configurations
 446         self._load_testbed_proxies()
 447
 448         # recreate testbed proxies by reconnecting only
 449         self._init_testbed_controllers(recover = True)
 450
 451     def is_finished(self, guid):
 452         for testbed in self._testbeds.values():
 453             for guid_ in testbed.guids:
 454                 if guid_ == guid:
 455                     return testbed.status(guid) == STATUS_FINISHED
 456         raise RuntimeError("No element exists with guid %d" % guid)
 457
 458     def set(self, testbed_guid, guid, name, value, time = TIME_NOW):
 459         testbed = self._testbeds[testbed_guid]
 460         testbed.set(guid, name, value, time)
 461
 462     def get(self, testbed_guid, guid, name, time = TIME_NOW):
 463         testbed = self._testbeds[testbed_guid]
 464         return testbed.get(guid, name, time)
 465
 466     def shutdown(self):
 467        for testbed in self._testbeds.values():
 468            testbed.shutdown()
 469
 470     @staticmethod
 471     def _netref_component_split(component):
 472         match = COMPONENT_PATTERN.match(component)
 473         if match:
 474             return match.group("kind"), match.group("index")
 475         else:
 476             return component, None
 477
 478     def do_netrefs(self, fail_if_undefined = False):
 479         COMPONENT_GETTERS = {
 480             'addr':
 481                 lambda testbed, guid, index, name:
 482                     testbed.get_address(guid, index, name),
 483             'route' :
 484                 lambda testbed, guid, index, name:
 485                     testbed.get_route(guid, index, name),
 486             'trace' :
 487                 lambda testbed, guid, index, name:
 488                     testbed.trace(guid, index, name),
 489             '' :
 490                 lambda testbed, guid, index, name:
 491                     testbed.get(guid, name),
 492         }
 493
 494         for (testbed_guid, guid), attrs in self._netrefs.iteritems():
 495             testbed = self._testbeds[testbed_guid]
 496             for name in attrs:
 497                 value = testbed.get(guid, name)
 498                 if isinstance(value, basestring):
 499                     match = ATTRIBUTE_PATTERN_BASE.search(value)
 500                     if match:
 501                         label = match.group("label")
 502                         if label.startswith('GUID-'):
 503                             ref_guid = int(label[5:])
 504                             if ref_guid:
 505                                 expr = match.group("expr")
 506                                 component = match.group("component")[1:] # skip the dot
 507                                 attribute = match.group("attribute")
 508
 509                                 # split compound components into component kind and index
 510                                 # eg: 'addr[0]' -> ('addr', '0')
 511                                 component, component_index = self._netref_component_split(component)
 512
 513                                 # find object and resolve expression
 514                                 for ref_testbed in self._testbeds.itervalues():
 515                                     if component not in COMPONENT_GETTERS:
 516                                         raise ValueError, "Malformed netref: %r - unknown component" % (expr,)
 517                                     else:
 518                                         ref_value = COMPONENT_GETTERS[component](
 519                                             ref_testbed, ref_guid, component_index, attribute)
 520                                         if ref_value:
 521                                             testbed.set(guid, name,
 522                                                     value.replace(match.group(), ref_value))
 523                                             break
 524                                 else:
 525                                     # couldn't find value
 526                                     if fail_if_undefined:
 527                                         raise ValueError, "Unresolvable GUID: %r, in netref: %r" % (ref_guid, expr)
 528
 529     def _init_testbed_controllers(self, recover = False):
 530         parser = XmlExperimentParser()
 531         data = parser.from_xml_to_data(self._experiment_xml)
 532         element_guids = list()
 533         label_guids = dict()
 534         data_guids = data.guids
 535
 536         # create testbed controllers
 537         for guid in data_guids:
 538             if data.is_testbed_data(guid):
 539                 self._create_testbed_controller(guid, data, element_guids,
 540                         recover)
 541             else:
 542                 element_guids.append(guid)
 543                 label = data.get_attribute_data(guid, "label")
 544                 if label is not None:
 545                     if label in label_guids:
 546                         raise RuntimeError, "Label %r is not unique" % (label,)
 547                     label_guids[label] = guid
 548
 549         # replace references to elements labels for its guid
 550         self._resolve_labels(data, data_guids, label_guids)
 551
 552         # program testbed controllers
 553         if not recover:
 554             self._program_testbed_controllers(element_guids, data)
 555
 556     def _resolve_labels(self, data, data_guids, label_guids):
 557         netrefs = self._netrefs
 558         for guid in data_guids:
 559             if not data.is_testbed_data(guid):
 560                 for name, value in data.get_attribute_data(guid):
 561                     if isinstance(value, basestring):
 562                         match = ATTRIBUTE_PATTERN_BASE.search(value)
 563                         if match:
 564                             label = match.group("label")
 565                             if not label.startswith('GUID-'):
 566                                 ref_guid = label_guids.get(label)
 567                                 if ref_guid is not None:
 568                                     value = ATTRIBUTE_PATTERN_BASE.sub(
 569                                         ATTRIBUTE_PATTERN_GUID_SUB % dict(
 570                                             guid = 'GUID-%d' % (ref_guid,),
 571                                             expr = match.group("expr"),
 572                                             label = label),
 573                                         value)
 574                                     data.set_attribute_data(guid, name, value)
 575
 576                                     # memorize which guid-attribute pairs require
 577                                     # postprocessing, to avoid excessive controller-testbed
 578                                     # communication at configuration time
 579                                     # (which could require high-latency network I/O)
 580                                     (testbed_guid, factory_id) = data.get_box_data(guid)
 581                                     netrefs.setdefault((testbed_guid, guid), set()).add(name)
 582
 583     def _create_testbed_controller(self, guid, data, element_guids, recover):
 584         (testbed_id, testbed_version) = data.get_testbed_data(guid)
 585         deployment_config = self._deployment_config.get(guid)
 586
 587         if deployment_config is None:
 588             # need to create one
 589             deployment_config = self._deployment_config[guid] = proxy.AccessConfiguration()
 590
 591             for (name, value) in data.get_attribute_data(guid):
 592                 if value is not None and deployment_config.has_attribute(name):
 593                     deployment_config.set_attribute_value(name, value)
 594
 595         if deployment_config is not None:
 596             # force recovery mode
 597             deployment_config.set_attribute_value("recover",recover)
 598
 599         testbed = proxy.create_testbed_controller(testbed_id,
 600                 testbed_version, deployment_config)
 601         for (name, value) in data.get_attribute_data(guid):
 602             testbed.defer_configure(name, value)
 603         self._testbeds[guid] = testbed
 604
 605     def _program_testbed_controllers(self, element_guids, data):
 606         for guid in element_guids:
 607             (testbed_guid, factory_id) = data.get_box_data(guid)
 608             testbed = self._testbeds[testbed_guid]
 609             testbed.defer_create(guid, factory_id)
 610             for (name, value) in data.get_attribute_data(guid):
 611                 testbed.defer_create_set(guid, name, value)
 612
 613         for guid in element_guids:
 614             (testbed_guid, factory_id) = data.get_box_data(guid)
 615             testbed = self._testbeds[testbed_guid]
 616             for (connector_type_name, cross_guid, cross_connector_type_name) \
 617                     in data.get_connection_data(guid):
 618                 (testbed_guid, factory_id) = data.get_box_data(guid)
 619                 (cross_testbed_guid, cross_factory_id) = data.get_box_data(
 620                         cross_guid)
 621                 if testbed_guid == cross_testbed_guid:
 622                     testbed.defer_connect(guid, connector_type_name,
 623                             cross_guid, cross_connector_type_name)
 624                 else:
 625                     cross_testbed = self._testbeds[cross_testbed_guid]
 626                     cross_testbed_id = cross_testbed.testbed_id
 627                     testbed.defer_cross_connect(guid, connector_type_name, cross_guid,
 628                             cross_testbed_guid, cross_testbed_id, cross_factory_id,
 629                             cross_connector_type_name)
 630                     # save cross data for later
 631                     self._add_crossdata(testbed_guid, guid, cross_testbed_guid,
 632                             cross_guid)
 633             for trace_id in data.get_trace_data(guid):
 634                 testbed.defer_add_trace(guid, trace_id)
 635             for (autoconf, address, netprefix, broadcast) in \
 636                     data.get_address_data(guid):
 637                 if address != None:
 638                     testbed.defer_add_address(guid, address, netprefix,
 639                             broadcast)
 640             for (destination, netprefix, nexthop) in data.get_route_data(guid):
 641                 testbed.defer_add_route(guid, destination, netprefix, nexthop)
 642
 643     def _add_crossdata(self, testbed_guid, guid, cross_testbed_guid, cross_guid):
 644         if testbed_guid not in self._cross_data:
 645             self._cross_data[testbed_guid] = dict()
 646         if cross_testbed_guid not in self._cross_data[testbed_guid]:
 647             self._cross_data[testbed_guid][cross_testbed_guid] = set()
 648         self._cross_data[testbed_guid][cross_testbed_guid].add(cross_guid)
 649
 650     def _get_cross_data(self, testbed_guid):
 651         cross_data = dict()
 652         if not testbed_guid in self._cross_data:
 653             return cross_data
 654         for cross_testbed_guid, guid_list in \
 655                 self._cross_data[testbed_guid].iteritems():
 656             cross_data[cross_testbed_guid] = dict()
 657             cross_testbed = self._testbeds[cross_testbed_guid]
 658             for cross_guid in guid_list:
 659                 elem_cross_data = dict()
 660                 cross_data[cross_testbed_guid][cross_guid] = elem_cross_data
 661                 attributes_list = cross_testbed.get_attribute_list(cross_guid)
 662                 for attr_name in attributes_list:
 663                     attr_value = cross_testbed.get(cross_guid, attr_name)
 664                     elem_cross_data[attr_name] = attr_value
 665         return cross_data
 666