src/nepi/resources/linux/ns3/ns3simulation.py

   1 #
   2 #    NEPI, a framework to manage network experiments
   3 #    Copyright (C) 2014 INRIA
   4 #
   5 #    This program is free software: you can redistribute it and/or modify
   6 #    it under the terms of the GNU General Public License as published by
   7 #    the Free Software Foundation, either version 3 of the License, or
   8 #    (at your option) any later version.
   9 #
  10 #    This program is distributed in the hope that it will be useful,
  11 #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 #    GNU General Public License for more details.
  14 #
  15 #    You should have received a copy of the GNU General Public License
  16 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 #
  18 # Author: Alina Quereilhac <alina.quereilhac@inria.fr>
  19
  20 from nepi.execution.attribute import Attribute, Flags, Types
  21 from nepi.execution.trace import Trace, TraceAttr
  22 from nepi.execution.resource import ResourceManager, clsinit_copy, \
  23         ResourceState, ResourceFactory
  24 from nepi.resources.linux.application import LinuxApplication
  25 from nepi.util.timefuncs import tnow, tdiffsec
  26 from nepi.resources.ns3.ns3simulation import NS3Simulation
  27 from nepi.resources.ns3.ns3wrapper import SIMULATOR_UUID, GLOBAL_VALUE_UUID, \
  28         IPV4_GLOBAL_ROUTING_HELPER_UUID
  29 from nepi.resources.linux.ns3.ns3client import LinuxNS3Client
  30
  31 import os
  32 import time
  33 import threading
  34
  35 ## TODO: Clean up DCE part. All that is DCE specific should go
  36 ##       in the linux ns3dceapplication.py
  37
  38 @clsinit_copy
  39 class LinuxNS3Simulation(LinuxApplication, NS3Simulation):
  40     _rtype = "LinuxNS3Simulation"
  41
  42     @classmethod
  43     def _register_attributes(cls):
  44         impl_type = Attribute("simulatorImplementationType",
  45                 "The object class to use as the simulator implementation",
  46             allowed = ["ns3::DefaultSimulatorImpl", "ns3::RealtimeSimulatorImpl"],
  47             default = "ns3::DefaultSimulatorImpl",
  48             type = Types.Enumerate,
  49             flags = Flags.Design)
  50
  51         sched_type = Attribute("schedulerType",
  52                 "The object class to use as the scheduler implementation",
  53                 allowed = ["ns3::MapScheduler",
  54                             "ns3::ListScheduler",
  55                             "ns3::HeapScheduler",
  56                             "ns3::MapScheduler",
  57                             "ns3::CalendarScheduler"
  58                     ],
  59             default = "ns3::MapScheduler",
  60             type = Types.Enumerate,
  61             flags = Flags.Design)
  62
  63         check_sum = Attribute("checksumEnabled",
  64                 "A global switch to enable all checksums for all protocols",
  65             default = False,
  66             type = Types.Bool,
  67             flags = Flags.Design)
  68
  69         ns_log = Attribute("nsLog",
  70             "NS_LOG environment variable. " \
  71                     " Will only generate output if ns-3 is compiled in DEBUG mode. ",
  72             flags = Flags.Design)
  73
  74         verbose = Attribute("verbose",
  75             "True to output debugging info from the ns3 client-server communication",
  76             type = Types.Bool,
  77             flags = Flags.Design)
  78
  79         enable_dump = Attribute("enableDump",
  80             "Enable dumping the remote executed ns-3 commands to a script "
  81             "in order to later reproduce and debug the experiment",
  82             type = Types.Bool,
  83             default = False,
  84             flags = Flags.Design)
  85
  86         build_mode = Attribute("buildMode",
  87             "Mode used to build ns-3 with waf. One if: debug, release, oprimized ",
  88             default = "optimized",
  89             allowed = ["debug", "release", "optimized"],
  90             type = Types.Enumerate,
  91             flags = Flags.Design)
  92
  93         ns3_version = Attribute("ns3Version",
  94             "Version of ns-3 to install from nsam repo",
  95             default = "ns-3.20",
  96             #default = "ns-3-dev",
  97             flags = Flags.Design)
  98
  99         pybindgen_version = Attribute("pybindgenVersion",
 100             "Version of pybindgen to install from bazar repo",
 101             default = "868",
 102             #default = "876",
 103             flags = Flags.Design)
 104
 105         dce_version = Attribute("dceVersion",
 106             "Version of dce to install from nsam repo (tag branch for repo)",
 107             #default = "dce-1.3",
 108             default = "dce-dev",
 109             flags = Flags.Design)
 110
 111         populate_routing_tables = Attribute("populateRoutingTables",
 112             "Invokes  Ipv4GlobalRoutingHelper.PopulateRoutingTables() ",
 113             default = False,
 114             type = Types.Bool,
 115             flags = Flags.Design)
 116
 117         stoptime = Attribute("StopTime",
 118             "Time at which the simulation will stop",
 119             flags = Flags.Design)
 120
 121         cls._register_attribute(impl_type)
 122         cls._register_attribute(sched_type)
 123         cls._register_attribute(check_sum)
 124         cls._register_attribute(ns_log)
 125         cls._register_attribute(enable_dump)
 126         cls._register_attribute(verbose)
 127         cls._register_attribute(build_mode)
 128         cls._register_attribute(ns3_version)
 129         cls._register_attribute(pybindgen_version)
 130         cls._register_attribute(dce_version)
 131         cls._register_attribute(populate_routing_tables)
 132         cls._register_attribute(stoptime)
 133
 134     def __init__(self, ec, guid):
 135         LinuxApplication.__init__(self, ec, guid)
 136         NS3Simulation.__init__(self)
 137
 138         self._client = None
 139         self._home = "ns3-simu-%s" % self.guid
 140         self._socket_name = "ns3-%s.sock" % os.urandom(4).encode('hex')
 141         self._enable_dce = None
 142
 143     @property
 144     def socket_name(self):
 145         return self._socket_name
 146
 147     @property
 148     def remote_socket(self):
 149         return os.path.join(self.run_home, self.socket_name)
 150
 151     def trace(self, name, attr = TraceAttr.ALL, block = 512, offset = 0):
 152         # stout needs to get flushed on the ns-3 server side, else we will
 153         # get an empty stream. We try twice to retrieve the stream
 154         # if we get empty stdout since the stream might not be
 155         # flushed immediately.
 156         if name.endswith("stdout"):
 157             self._client.flush()
 158             result = LinuxApplication.trace(self, name, attr, block, offset)
 159             if result:
 160                 return result
 161             # Let the stream be flushed
 162             time.sleep(1)
 163
 164         return LinuxApplication.trace(self, name, attr, block, offset)
 165
 166     def upload_sources(self):
 167         self.node.mkdir(os.path.join(self.node.src_dir, "ns3wrapper"))
 168
 169         # upload ns3 wrapper python script
 170         ns3_wrapper = os.path.join(os.path.dirname(__file__), "..", "..", "ns3",
 171                 "ns3wrapper.py")
 172
 173         self.node.upload(ns3_wrapper,
 174                 os.path.join(self.node.src_dir, "ns3wrapper", "ns3wrapper.py"),
 175                 overwrite = False)
 176
 177         # upload ns3 wrapper debug python script
 178         ns3_wrapper_debug = os.path.join(os.path.dirname(__file__), "..", "..", "ns3",
 179                 "ns3wrapper_debug.py")
 180
 181         self.node.upload(ns3_wrapper_debug,
 182                 os.path.join(self.node.src_dir, "ns3wrapper", "ns3wrapper_debug.py"),
 183                 overwrite = False)
 184
 185         # upload ns3_server python script
 186         ns3_server = os.path.join(os.path.dirname(__file__), "..", "..", "ns3",
 187                 "ns3server.py")
 188
 189         self.node.upload(ns3_server,
 190                 os.path.join(self.node.src_dir, "ns3wrapper", "ns3server.py"),
 191                 overwrite = False)
 192
 193         if self.node.use_rpm:
 194             # upload pygccxml sources
 195             pygccxml_tar = os.path.join(os.path.dirname(__file__), "dependencies",
 196                     "%s.tar.gz" % self.pygccxml_version)
 197
 198             self.node.upload(pygccxml_tar,
 199                     os.path.join(self.node.src_dir, "%s.tar.gz" % self.pygccxml_version),
 200                     overwrite = False)
 201
 202         # Upload user defined ns-3 sources
 203         self.node.mkdir(os.path.join(self.node.src_dir, "ns-3"))
 204         src_dir = os.path.join(self.node.src_dir, "ns-3")
 205
 206         super(LinuxNS3Simulation, self).upload_sources(src_dir = src_dir)
 207
 208     def upload_extra_sources(self, sources = None, src_dir = None):
 209         return super(LinuxNS3Simulation, self).upload_sources(
 210                 sources = sources,
 211                 src_dir = src_dir)
 212
 213     def upload_start_command(self):
 214         command = self.get("command")
 215         env = self.get("env")
 216
 217         # We want to make sure the ccnd is running
 218         # before the experiment starts.
 219         # Run the command as a bash script in background,
 220         # in the host ( but wait until the command has
 221         # finished to continue )
 222         env = self.replace_paths(env)
 223         command = self.replace_paths(command)
 224
 225         shfile = os.path.join(self.app_home, "start.sh")
 226         self.node.upload_command(command,
 227                     shfile = shfile,
 228                     env = env,
 229                     overwrite = True)
 230
 231         # Run the ns3wrapper
 232         self._run_in_background()
 233
 234         # Wait until the remote socket is created
 235         self.wait_remote_socket()
 236
 237     def configure(self):
 238         if self.has_changed("simulatorImplementationType"):
 239             simu_type = self.get("simulatorImplementationType")
 240             stype = self.create("StringValue", simu_type)
 241             self.invoke(GLOBAL_VALUE_UUID, "Bind", "SimulatorImplementationType", stype)
 242
 243         if self.has_changed("checksumEnabled"):
 244             check_sum = self.get("checksumEnabled")
 245             btrue = self.create("BooleanValue", check_sum)
 246             self.invoke(GLOBAL_VALUE_UUID, "Bind", "ChecksumEnabled", btrue)
 247
 248         if self.has_changed("schedulerType"):
 249             sched_type = self.get("schedulerType")
 250             stype = self.create("StringValue", sched_type)
 251             self.invoke(GLOBAL_VALUE_UUID, "Bind", "SchedulerType", btrue)
 252
 253     def do_deploy(self):
 254         if not self.node or self.node.state < ResourceState.READY:
 255             self.debug("---- RESCHEDULING DEPLOY ---- node state %s " % self.node.state )
 256
 257             # ccnd needs to wait until node is deployed and running
 258             self.ec.schedule(self.reschedule_delay, self.deploy)
 259         else:
 260             if not self.get("command"):
 261                 self.set("command", self._start_command)
 262
 263             if not self.get("depends"):
 264                 self.set("depends", self._dependencies)
 265
 266             if self.get("sources"):
 267                 sources = self.get("sources")
 268                 source = sources.split(" ")[0]
 269                 basename = os.path.basename(source)
 270                 version = ( basename.strip().replace(".tar.gz", "")
 271                     .replace(".tar","")
 272                     .replace(".gz","")
 273                     .replace(".zip","") )
 274
 275                 self.set("ns3Version", version)
 276                 self.set("sources", source)
 277
 278             if not self.get("build"):
 279                 self.set("build", self._build)
 280
 281             if not self.get("install"):
 282                 self.set("install", self._install)
 283
 284             if not self.get("env"):
 285                 self.set("env", self._environment)
 286
 287             self.do_discover()
 288             self.do_provision()
 289
 290             # Create client
 291             self._client = LinuxNS3Client(self)
 292
 293             self.configure()
 294
 295             self.set_ready()
 296
 297     def do_start(self):
 298         """ Starts simulation execution
 299
 300         """
 301         self.info("Starting")
 302
 303         if self.state == ResourceState.READY:
 304             if self.get("populateRoutingTables") == True:
 305                 self.invoke(IPV4_GLOBAL_ROUTING_HELPER_UUID, "PopulateRoutingTables")
 306
 307             time = self.get("StopTime")
 308             if time:
 309                 self._client.stop(time=time)
 310
 311             self._client.start()
 312
 313             self.set_started()
 314         else:
 315             msg = " Failed to execute command '%s'" % command
 316             self.error(msg, out, err)
 317             raise RuntimeError, msg
 318
 319     def do_stop(self):
 320         """ Stops simulation execution
 321
 322         """
 323         if self.state == ResourceState.STARTED:
 324             if not self.get("StopTime"):
 325                 self._client.stop()
 326             self.set_stopped()
 327
 328     def do_release(self):
 329         self.info("Releasing resource")
 330
 331         tear_down = self.get("tearDown")
 332         if tear_down:
 333             self.node.execute(tear_down)
 334
 335         self.do_stop()
 336         self._client.shutdown()
 337         LinuxApplication.do_stop(self)
 338
 339         super(LinuxApplication, self).do_release()
 340
 341     @property
 342     def enable_dce(self):
 343         if self._enable_dce is None:
 344             from nepi.resources.ns3.ns3dceapplication import NS3BaseDceApplication
 345             rclass = ResourceFactory.get_resource_type(
 346                     NS3BaseDceApplication.get_rtype())
 347
 348             self._enable_dce = False
 349             for guid in self.ec.resources:
 350                 rm = self.ec.get_resource(guid)
 351                 if isinstance(rm, rclass):
 352                     self._enable_dce = True
 353                     break
 354
 355         return self._enable_dce
 356
 357     @property
 358     def _start_command(self):
 359         command = []
 360
 361         command.append("PYTHONPATH=$PYTHONPATH:${SRC}/ns3wrapper/")
 362
 363         command.append("python ${SRC}/ns3wrapper/ns3server.py -S %s" % \
 364                 os.path.basename(self.remote_socket) )
 365
 366         ns_log = self.get("nsLog")
 367         if ns_log:
 368             command.append("-L '%s'" % ns_log)
 369
 370         if self.get("enableDump"):
 371             command.append("-D")
 372
 373         if self.get("verbose"):
 374             command.append("-v")
 375
 376         command = " ".join(command)
 377         return command
 378
 379     @property
 380     def _dependencies(self):
 381         if self.node.use_rpm:
 382             return ( " gcc gcc-c++ python python-devel mercurial bzr tcpdump socat gccxml unzip")
 383         elif self.node.use_deb:
 384             return ( " gcc g++ python python-dev mercurial bzr tcpdump socat gccxml python-pygccxml unzip")
 385         return ""
 386
 387     @property
 388     def ns3_repo(self):
 389         return "http://code.nsnam.org"
 390
 391     @property
 392     def pygccxml_version(self):
 393         return "pygccxml-1.0.0"
 394
 395     @property
 396     def dce_repo(self):
 397         return "http://code.nsnam.org/ns-3-dce"
 398         #eturn "http://code.nsnam.org/epmancini/ns-3-dce"
 399
 400     @property
 401     def dce_version(self):
 402         dce_version = self.get("dceVersion")
 403         return dce_version or "dce-dev"
 404
 405     @property
 406     def ns3_build_location(self):
 407         location = "${BIN}/ns-3/%(ns3_version)s%(dce_version)s/%(build_mode)s/build" \
 408                     % {
 409                         "ns3_version": self.get("ns3Version"),
 410                         "dce_version": "-%s" % self.get("dceVersion") \
 411                                 if self.enable_dce else "",
 412                         "build_mode": self.get("buildMode"),
 413                       }
 414
 415         return location
 416
 417
 418     @property
 419     def ns3_src_location(self):
 420         location = "${SRC}/ns-3/%(ns3_version)s" \
 421                     % {
 422                         "ns3_version": self.get("ns3Version"),
 423                       }
 424
 425         return location
 426
 427     @property
 428     def dce_src_location(self):
 429         location = "${SRC}/ns-3-dce/%(dce_version)s" \
 430                    % {
 431                         "dce_version": self.get("dceVersion"),
 432                      }
 433
 434         return location
 435
 436     @property
 437     def _clone_ns3_command(self):
 438         source = self.get("sources")
 439
 440         if not source:
 441             clone_ns3_cmd = "hg clone %(ns3_repo)s/%(ns3_version)s %(ns3_src)s" \
 442                     % {
 443                         "ns3_version": self.get("ns3Version"),
 444                         "ns3_repo": self.ns3_repo,
 445                         "ns3_src": self.ns3_src_location,
 446                       }
 447         else:
 448             if source.find(".tar.gz") > -1:
 449                 clone_ns3_cmd = (
 450                             "tar xzf ${SRC}/ns-3/%(basename)s "
 451                             " --strip-components=1 -C %(ns3_src)s"
 452                             ) % {
 453                                 "basename": os.path.basename(source),
 454                                 "ns3_src": self.ns3_src_location,
 455                                 }
 456             elif source.find(".tar") > -1:
 457                 clone_ns3_cmd = (
 458                             "tar xf ${SRC}/ns-3/%(basename)s "
 459                             " --strip-components=1 -C %(ns3_src)s"
 460                             ) % {
 461                                 "basename": os.path.basename(source),
 462                                 "ns3_src": self.ns3_src_location,
 463                                 }
 464             elif source.find(".zip") > -1:
 465                 basename = os.path.basename(source)
 466                 bare_basename = basename.replace(".zip", "")
 467
 468                 clone_ns3_cmd = (
 469                             "unzip ${SRC}/ns-3/%(basename)s && "
 470                             "mv ${SRC}/ns-3/%(bare_basename)s %(ns3_src)s"
 471                             ) % {
 472                                 "bare_basename": basename_name,
 473                                 "basename": basename,
 474                                 "ns3_src": self.ns3_src_location,
 475                                 }
 476
 477         return clone_ns3_cmd
 478
 479     @property
 480     def _clone_dce_command(self):
 481         clone_dce_cmd = " echo 'DCE will not be built' "
 482
 483         if self.enable_dce:
 484             dce_version = self.dce_version
 485             dce_tag = ""
 486             if dce_version != "dce-dev":
 487                 dce_tag = "-r %s" % dce_version
 488
 489             clone_dce_cmd = (
 490                         # DCE installation
 491                         # Test if dce is alredy cloned
 492                         " ( "
 493                         "  ( "
 494                         "    ( test -d %(dce_src)s ) "
 495                         "   && echo 'dce binaries found, nothing to do'"
 496                         "  ) "
 497                         " ) "
 498                         "  || "
 499                         # Get dce source code
 500                         " ( "
 501                         "   mkdir -p %(dce_src)s && "
 502                         "   hg clone %(dce_repo)s %(dce_tag)s %(dce_src)s"
 503                         " ) "
 504                      ) % {
 505                             "dce_repo": self.dce_repo,
 506                             "dce_tag": dce_tag,
 507                             "dce_src": self.dce_src_location,
 508                          }
 509
 510         return clone_dce_cmd
 511
 512     @property
 513     def _build(self):
 514         # If the user defined local sources for ns-3, we uncompress the sources
 515         # on the remote sources directory. Else we clone ns-3 from the official repo.
 516         clone_ns3_cmd = self._clone_ns3_command
 517         clone_dce_cmd = self._clone_dce_command
 518
 519         ns3_build_cmd = (
 520                 # NS3 installation
 521                 "( "
 522                 " ( "
 523                 # Test if ns-3 is alredy cloned
 524                 "  ((( test -d %(ns3_src)s ) || "
 525                 "    ( test -d ${NS3BINDINGS:='None'} && test -d ${NS3LIBRARIES:='None'})) "
 526                 "  && echo 'ns-3 binaries found, nothing to do' )"
 527                 " ) "
 528                 "  || "
 529                 # If not, install ns-3 and its dependencies
 530                 " (   "
 531                 # Install pygccxml
 532                 "   (   "
 533                 "     ( "
 534                 "       python -c 'import pygccxml' && "
 535                 "       echo 'pygccxml not found' "
 536                 "     ) "
 537                 "      || "
 538                 "     ( "
 539                 "       tar xf ${SRC}/%(pygccxml_version)s.tar.gz -C ${SRC} && "
 540                 "       cd ${SRC}/%(pygccxml_version)s && "
 541                 "       python setup.py build && "
 542                 "       sudo -S python setup.py install "
 543                 "     ) "
 544                 "   ) "
 545                 # Install pybindgen
 546                 "  && "
 547                 "   (   "
 548                 "     ( "
 549                 "       test -d ${SRC}/pybindgen/%(pybindgen_version)s && "
 550                 "       echo 'binaries found, nothing to do' "
 551                 "     ) "
 552                 "      || "
 553                 # If not, clone and build
 554                 "      ( cd ${SRC} && "
 555                 "        mkdir -p ${SRC}/pybindgen && "
 556                 "        bzr checkout lp:pybindgen -r %(pybindgen_version)s ${SRC}/pybindgen/%(pybindgen_version)s && "
 557                 "        cd ${SRC}/pybindgen/%(pybindgen_version)s && "
 558                 "        ./waf configure && "
 559                 "        ./waf "
 560                 "      ) "
 561                 "   ) "
 562                 " && "
 563                 # Get ns-3 source code
 564                 "  ( "
 565                 "     mkdir -p %(ns3_src)s && "
 566                 "     %(clone_ns3_cmd)s "
 567                 "  ) "
 568                 " ) "
 569                 ") "
 570                 " && "
 571                 "( "
 572                 "   %(clone_dce_cmd)s "
 573                 ") "
 574              ) % {
 575                     "ns3_src": self.ns3_src_location,
 576                     "pybindgen_version": self.get("pybindgenVersion"),
 577                     "pygccxml_version": self.pygccxml_version,
 578                     "clone_ns3_cmd": clone_ns3_cmd,
 579                     "clone_dce_cmd": clone_dce_cmd,
 580                  }
 581
 582         return ns3_build_cmd
 583
 584     @property
 585     def _install_dce_command(self):
 586         install_dce_cmd = " echo 'DCE will not be installed'"
 587
 588         if self.enable_dce:
 589             install_dce_cmd = (
 590                         " ( "
 591                         "   ((test -d %(ns3_build)s/bin_dce ) && "
 592                         "    echo 'dce binaries found, nothing to do' )"
 593                         " ) "
 594                         " ||"
 595                         " (   "
 596                          # If not, copy build to dce
 597                         "  cd %(dce_src)s && "
 598                         "  rm -rf %(dce_src)s/build && "
 599                         "  ./waf configure %(enable_opt)s --with-pybindgen=${SRC}/pybindgen/%(pybindgen_version)s "
 600                         "  --prefix=%(ns3_build)s --with-ns3=%(ns3_build)s && "
 601                         "  ./waf build && "
 602                         "  ./waf install && "
 603                         "  [ ! -e %(ns3_build)s/lib/python/site-packages/ns/dce.so ] && "
 604                         "   mv %(ns3_build)s/lib*/python*/site-packages/ns/dce.so %(ns3_build)s/lib/python/site-packages/ns/ "
 605                         " )"
 606                 ) % {
 607                     "pybindgen_version": self.get("pybindgenVersion"),
 608                     "enable_opt": "--enable-opt" if  self.get("buildMode") == "optimized" else "",
 609                     "ns3_build": self.ns3_build_location,
 610                     "dce_src": self.dce_src_location,
 611                      }
 612
 613         return install_dce_cmd
 614
 615     @property
 616     def _install(self):
 617         install_dce_cmd = self._install_dce_command
 618
 619         install_ns3_cmd = (
 620                  # Test if ns-3 is alredy installed
 621                 "("
 622                 " ( "
 623                 "  ( ( (test -d %(ns3_build)s/lib ) || "
 624                 "    (test -d ${NS3BINDINGS:='None'} && test -d ${NS3LIBRARIES:='None'}) ) && "
 625                 "    echo 'binaries found, nothing to do' )"
 626                 " ) "
 627                 " ||"
 628                 " (   "
 629                  # If not, copy ns-3 build to bin
 630                 "  mkdir -p %(ns3_build)s && "
 631                 "  cd %(ns3_src)s && "
 632                 "  rm -rf %(ns3_src)s/build && "
 633                 "  ./waf configure -d %(build_mode)s --with-pybindgen=${SRC}/pybindgen/%(pybindgen_version)s "
 634                 "  --prefix=%(ns3_build)s && "
 635                 "  ./waf build && "
 636                 "  ./waf install && "
 637                 "  mv %(ns3_build)s/lib*/python* %(ns3_build)s/lib/python "
 638                 " )"
 639                 ") "
 640                 " && "
 641                 "( "
 642                 "   %(install_dce_cmd)s "
 643                 ") "
 644               ) % {
 645                     "pybindgen_version": self.get("pybindgenVersion"),
 646                     "build_mode": self.get("buildMode"),
 647                     "install_dce_cmd": install_dce_cmd,
 648                     "ns3_build": self.ns3_build_location,
 649                     "ns3_src": self.ns3_src_location,
 650                  }
 651
 652         return install_ns3_cmd
 653
 654     @property
 655     def _environment(self):
 656         env = []
 657         env.append("PYTHONPATH=$PYTHONPATH:${NS3BINDINGS:=%(ns3_build)s/lib/python/site-packages}" % {
 658                     "ns3_build": self.ns3_build_location
 659                  })
 660         # If NS3LIBRARIES is defined and not empty, assign its value,
 661         # if not assign ns3_build_home/lib/ to NS3LIBRARIES and LD_LIBARY_PATH
 662         env.append("LD_LIBRARY_PATH=${NS3LIBRARIES:=%(ns3_build)s/lib}" % {
 663                     "ns3_build": self.ns3_build_location
 664                  })
 665         env.append("DCE_PATH=$NS3LIBRARIES/../bin_dce")
 666         env.append("DCE_ROOT=$NS3LIBRARIES/..")
 667
 668         return " ".join(env)
 669
 670     def replace_paths(self, command):
 671         """
 672         Replace all special path tags with shell-escaped actual paths.
 673         """
 674         return ( command
 675             .replace("${USR}", self.node.usr_dir)
 676             .replace("${LIB}", self.node.lib_dir)
 677             .replace("${BIN}", self.node.bin_dir)
 678             .replace("${SRC}", self.node.src_dir)
 679             .replace("${SHARE}", self.node.share_dir)
 680             .replace("${EXP}", self.node.exp_dir)
 681             .replace("${EXP_HOME}", self.node.exp_home)
 682             .replace("${APP_HOME}", self.app_home)
 683             .replace("${RUN_HOME}", self.run_home)
 684             .replace("${NODE_HOME}", self.node.node_home)
 685             .replace("${HOME}", self.node.home_dir)
 686             # If NS3LIBRARIES is defined and not empty, use that value,
 687             # if not use ns3_build_home/lib/
 688             .replace("${BIN_DCE}", "${NS3LIBRARIES-%s/lib}/../bin_dce" % \
 689                     self.ns3_build_location)
 690             )
 691
 692     def valid_connection(self, guid):
 693         # TODO: Validate!
 694         return True
 695
 696     def wait_remote_socket(self):
 697         """ Waits until the remote socket is created
 698         """
 699         command = " [ -e %s ] && echo 'DONE' " % self.remote_socket
 700
 701         for i in xrange(200):
 702             (out, err), proc = self.node.execute(command, retry = 1,
 703                     with_lock = True)
 704
 705             if out.find("DONE") > -1:
 706                 break
 707         else:
 708             raise RuntimeError("Remote socket not found at %s" % \
 709                     self.remote_socket)
 710
 711