src/allmydata/test/test_client.py

   1 import os, sys
   2 from twisted.trial import unittest
   3 from twisted.application import service
   4
   5 import allmydata
   6 from allmydata.node import Node, OldConfigError, OldConfigOptionError, MissingConfigEntry, UnescapedHashError
   7 from allmydata import client
   8 from allmydata.storage_client import StorageFarmBroker
   9 from allmydata.manhole import AuthorizedKeysManhole
  10 from allmydata.util import base32, fileutil
  11 from allmydata.interfaces import IFilesystemNode, IFileNode, \
  12      IImmutableFileNode, IMutableFileNode, IDirectoryNode
  13 from foolscap.api import flushEventualQueue
  14 import allmydata.test.common_util as testutil
  15
  16 import mock
  17
  18 BASECONFIG = ("[client]\n"
  19               "introducer.furl = \n"
  20               )
  21
  22 BASECONFIG_I = ("[client]\n"
  23               "introducer.furl = %s\n"
  24               )
  25
  26 class Basic(testutil.ReallyEqualMixin, unittest.TestCase):
  27     def test_loadable(self):
  28         basedir = "test_client.Basic.test_loadable"
  29         os.mkdir(basedir)
  30         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
  31                            BASECONFIG)
  32         client.Client(basedir)
  33
  34     def test_comment(self):
  35         should_fail = [r"test#test", r"#testtest", r"test\\#test"]
  36         should_not_fail = [r"test\#test", r"test\\\#test", r"testtest"]
  37
  38         basedir = "test_client.Basic.test_comment"
  39         os.mkdir(basedir)
  40
  41         def write_config(s):
  42             config = ("[client]\n"
  43                       "introducer.furl = %s\n" % s)
  44             fileutil.write(os.path.join(basedir, "tahoe.cfg"), config)
  45
  46         for s in should_fail:
  47             self.failUnless(Node._contains_unescaped_hash(s))
  48             write_config(s)
  49             self.failUnlessRaises(UnescapedHashError, client.Client, basedir)
  50
  51         for s in should_not_fail:
  52             self.failIf(Node._contains_unescaped_hash(s))
  53             write_config(s)
  54             client.Client(basedir)
  55
  56
  57     @mock.patch('twisted.python.log.msg')
  58     def test_error_on_old_config_files(self, mock_log_msg):
  59         basedir = "test_client.Basic.test_error_on_old_config_files"
  60         os.mkdir(basedir)
  61         fileutil.write(os.path.join(basedir, "tahoe.cfg"),
  62                        BASECONFIG +
  63                        "[storage]\n" +
  64                        "enabled = false\n" +
  65                        "reserved_space = bogus\n")
  66         fileutil.write(os.path.join(basedir, "introducer.furl"), "")
  67         fileutil.write(os.path.join(basedir, "no_storage"), "")
  68         fileutil.write(os.path.join(basedir, "readonly_storage"), "")
  69         fileutil.write(os.path.join(basedir, "debug_discard_storage"), "")
  70
  71         e = self.failUnlessRaises(OldConfigError, client.Client, basedir)
  72         abs_basedir = fileutil.abspath_expanduser_unicode(unicode(basedir)).encode(sys.getfilesystemencoding())
  73         self.failUnlessIn(os.path.join(abs_basedir, "introducer.furl"), e.args[0])
  74         self.failUnlessIn(os.path.join(abs_basedir, "no_storage"), e.args[0])
  75         self.failUnlessIn(os.path.join(abs_basedir, "readonly_storage"), e.args[0])
  76         self.failUnlessIn(os.path.join(abs_basedir, "debug_discard_storage"), e.args[0])
  77
  78         for oldfile in ['introducer.furl', 'no_storage', 'readonly_storage',
  79                         'debug_discard_storage']:
  80             logged = [ m for m in mock_log_msg.call_args_list if
  81                        ("Found pre-Tahoe-LAFS-v1.3 configuration file" in str(m[0][0]) and oldfile in str(m[0][0])) ]
  82             self.failUnless(logged, (oldfile, mock_log_msg.call_args_list))
  83
  84         for oldfile in [
  85             'nickname', 'webport', 'keepalive_timeout', 'log_gatherer.furl',
  86             'disconnect_timeout', 'advertised_ip_addresses', 'helper.furl',
  87             'key_generator.furl', 'stats_gatherer.furl', 'sizelimit',
  88             'run_helper']:
  89             logged = [ m for m in mock_log_msg.call_args_list if
  90                        ("Found pre-Tahoe-LAFS-v1.3 configuration file" in str(m[0][0]) and oldfile in str(m[0][0])) ]
  91             self.failIf(logged, oldfile)
  92
  93     def test_secrets(self):
  94         basedir = "test_client.Basic.test_secrets"
  95         os.mkdir(basedir)
  96         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
  97                            BASECONFIG)
  98         c = client.Client(basedir)
  99         secret_fname = os.path.join(basedir, "private", "secret")
 100         self.failUnless(os.path.exists(secret_fname), secret_fname)
 101         renew_secret = c.get_renewal_secret()
 102         self.failUnless(base32.b2a(renew_secret))
 103         cancel_secret = c.get_cancel_secret()
 104         self.failUnless(base32.b2a(cancel_secret))
 105
 106     def test_nodekey_yes_storage(self):
 107         basedir = "test_client.Basic.test_nodekey_yes_storage"
 108         os.mkdir(basedir)
 109         fileutil.write(os.path.join(basedir, "tahoe.cfg"),
 110                        BASECONFIG)
 111         c = client.Client(basedir)
 112         self.failUnless(c.get_long_nodeid().startswith("v0-"))
 113
 114     def test_nodekey_no_storage(self):
 115         basedir = "test_client.Basic.test_nodekey_no_storage"
 116         os.mkdir(basedir)
 117         fileutil.write(os.path.join(basedir, "tahoe.cfg"),
 118                        BASECONFIG + "[storage]\n" + "enabled = false\n")
 119         c = client.Client(basedir)
 120         self.failUnless(c.get_long_nodeid().startswith("v0-"))
 121
 122     def test_reserved_1(self):
 123         basedir = "client.Basic.test_reserved_1"
 124         os.mkdir(basedir)
 125         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
 126                            BASECONFIG + \
 127                            "[storage]\n" + \
 128                            "enabled = true\n" + \
 129                            "reserved_space = 1000\n")
 130         c = client.Client(basedir)
 131         self.failUnlessEqual(c.getServiceNamed("storage").reserved_space, 1000)
 132
 133     def test_reserved_2(self):
 134         basedir = "client.Basic.test_reserved_2"
 135         os.mkdir(basedir)
 136         fileutil.write(os.path.join(basedir, "tahoe.cfg"),  \
 137                            BASECONFIG + \
 138                            "[storage]\n" + \
 139                            "enabled = true\n" + \
 140                            "reserved_space = 10K\n")
 141         c = client.Client(basedir)
 142         self.failUnlessEqual(c.getServiceNamed("storage").reserved_space, 10*1000)
 143
 144     def test_reserved_3(self):
 145         basedir = "client.Basic.test_reserved_3"
 146         os.mkdir(basedir)
 147         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
 148                            BASECONFIG + \
 149                            "[storage]\n" + \
 150                            "enabled = true\n" + \
 151                            "reserved_space = 5mB\n")
 152         c = client.Client(basedir)
 153         self.failUnlessEqual(c.getServiceNamed("storage").reserved_space,
 154                              5*1000*1000)
 155
 156     def test_reserved_4(self):
 157         basedir = "client.Basic.test_reserved_4"
 158         os.mkdir(basedir)
 159         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
 160                            BASECONFIG + \
 161                            "[storage]\n" + \
 162                            "enabled = true\n" + \
 163                            "reserved_space = 78Gb\n")
 164         c = client.Client(basedir)
 165         self.failUnlessEqual(c.getServiceNamed("storage").reserved_space,
 166                              78*1000*1000*1000)
 167
 168     def test_reserved_bad(self):
 169         basedir = "client.Basic.test_reserved_bad"
 170         os.mkdir(basedir)
 171         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
 172                            BASECONFIG + \
 173                            "[storage]\n" + \
 174                            "enabled = true\n" + \
 175                            "reserved_space = bogus\n")
 176         self.failUnlessRaises(ValueError, client.Client, basedir)
 177
 178     def test_web_staticdir(self):
 179         basedir = u"client.Basic.test_web_staticdir"
 180         os.mkdir(basedir)
 181         fileutil.write(os.path.join(basedir, "tahoe.cfg"),
 182                        BASECONFIG +
 183                        "[node]\n" +
 184                        "web.port = tcp:0:interface=127.0.0.1\n" +
 185                        "web.static = relative\n")
 186         c = client.Client(basedir)
 187         w = c.getServiceNamed("webish")
 188         abs_basedir = fileutil.abspath_expanduser_unicode(basedir)
 189         expected = fileutil.abspath_expanduser_unicode(u"relative", abs_basedir)
 190         self.failUnlessReallyEqual(w.staticdir, expected)
 191
 192     def test_manhole_keyfile(self):
 193         basedir = u"client.Basic.test_manhole_keyfile"
 194         os.mkdir(basedir)
 195         fileutil.write(os.path.join(basedir, "tahoe.cfg"),
 196                        BASECONFIG +
 197                        "[node]\n" +
 198                        "ssh.port = tcp:0:interface=127.0.0.1\n" +
 199                        "ssh.authorized_keys_file = relative\n")
 200         c = client.Client(basedir)
 201         m = [s for s in c if isinstance(s, AuthorizedKeysManhole)][0]
 202         abs_basedir = fileutil.abspath_expanduser_unicode(basedir)
 203         expected = fileutil.abspath_expanduser_unicode(u"relative", abs_basedir)
 204         self.failUnlessReallyEqual(m.keyfile, expected)
 205
 206     def _permute(self, sb, key):
 207         return [ s.get_longname() for s in sb.get_servers_for_psi(key) ]
 208
 209     def test_permute(self):
 210         sb = StorageFarmBroker(None, True)
 211         for k in ["%d" % i for i in range(5)]:
 212             ann = {"anonymous-storage-FURL": "pb://abcde@nowhere/fake",
 213                    "permutation-seed-base32": base32.b2a(k) }
 214             sb.test_add_rref(k, "rref", ann)
 215
 216         self.failUnlessReallyEqual(self._permute(sb, "one"), ['3','1','0','4','2'])
 217         self.failUnlessReallyEqual(self._permute(sb, "two"), ['0','4','2','1','3'])
 218         sb.servers.clear()
 219         self.failUnlessReallyEqual(self._permute(sb, "one"), [])
 220
 221     def test_versions(self):
 222         basedir = "test_client.Basic.test_versions"
 223         os.mkdir(basedir)
 224         fileutil.write(os.path.join(basedir, "tahoe.cfg"), \
 225                            BASECONFIG + \
 226                            "[storage]\n" + \
 227                            "enabled = true\n")
 228         c = client.Client(basedir)
 229         ss = c.getServiceNamed("storage")
 230         verdict = ss.remote_get_version()
 231         self.failUnlessReallyEqual(verdict["application-version"],
 232                                    str(allmydata.__full_version__))
 233         self.failIfEqual(str(allmydata.__version__), "unknown")
 234         self.failUnless("." in str(allmydata.__full_version__),
 235                         "non-numeric version in '%s'" % allmydata.__version__)
 236         all_versions = allmydata.get_package_versions_string()
 237         self.failUnless(allmydata.__appname__ in all_versions)
 238         # also test stats
 239         stats = c.get_stats()
 240         self.failUnless("node.uptime" in stats)
 241         self.failUnless(isinstance(stats["node.uptime"], float))
 242
 243     def test_helper_furl(self):
 244         basedir = "test_client.Basic.test_helper_furl"
 245         os.mkdir(basedir)
 246
 247         def _check(config, expected_furl):
 248             fileutil.write(os.path.join(basedir, "tahoe.cfg"),
 249                            BASECONFIG + config)
 250             c = client.Client(basedir)
 251             uploader = c.getServiceNamed("uploader")
 252             furl, connected = uploader.get_helper_info()
 253             self.failUnlessEqual(furl, expected_furl)
 254
 255         _check("", None)
 256         _check("helper.furl =\n", None)
 257         _check("helper.furl = \n", None)
 258         _check("helper.furl = None", None)
 259         _check("helper.furl = pb://blah\n", "pb://blah")
 260
 261     @mock.patch('allmydata.util.log.msg')
 262     @mock.patch('allmydata.frontends.drop_upload.DropUploader')
 263     def test_create_drop_uploader(self, mock_drop_uploader, mock_log_msg):
 264         class MockDropUploader(service.MultiService):
 265             name = 'drop-upload'
 266
 267             def __init__(self, client, upload_dircap, local_dir_utf8, inotify=None):
 268                 service.MultiService.__init__(self)
 269                 self.client = client
 270                 self.upload_dircap = upload_dircap
 271                 self.local_dir_utf8 = local_dir_utf8
 272                 self.inotify = inotify
 273
 274         mock_drop_uploader.side_effect = MockDropUploader
 275
 276         upload_dircap = "URI:DIR2:blah"
 277         local_dir_utf8 = u"loc\u0101l_dir".encode('utf-8')
 278         config = (BASECONFIG +
 279                   "[storage]\n" +
 280                   "enabled = false\n" +
 281                   "[drop_upload]\n" +
 282                   "enabled = true\n")
 283
 284         basedir1 = "test_client.Basic.test_create_drop_uploader1"
 285         os.mkdir(basedir1)
 286         fileutil.write(os.path.join(basedir1, "tahoe.cfg"),
 287                        config + "local.directory = " + local_dir_utf8 + "\n")
 288         self.failUnlessRaises(MissingConfigEntry, client.Client, basedir1)
 289
 290         fileutil.write(os.path.join(basedir1, "tahoe.cfg"), config)
 291         fileutil.write(os.path.join(basedir1, "private", "drop_upload_dircap"), "URI:DIR2:blah")
 292         self.failUnlessRaises(MissingConfigEntry, client.Client, basedir1)
 293
 294         fileutil.write(os.path.join(basedir1, "tahoe.cfg"),
 295                        config + "upload.dircap = " + upload_dircap + "\n")
 296         self.failUnlessRaises(OldConfigOptionError, client.Client, basedir1)
 297
 298         fileutil.write(os.path.join(basedir1, "tahoe.cfg"),
 299                        config + "local.directory = " + local_dir_utf8 + "\n")
 300         c1 = client.Client(basedir1)
 301         uploader = c1.getServiceNamed('drop-upload')
 302         self.failUnless(isinstance(uploader, MockDropUploader), uploader)
 303         self.failUnlessReallyEqual(uploader.client, c1)
 304         self.failUnlessReallyEqual(uploader.upload_dircap, upload_dircap)
 305         self.failUnlessReallyEqual(uploader.local_dir_utf8, local_dir_utf8)
 306         self.failUnless(uploader.inotify is None, uploader.inotify)
 307         self.failUnless(uploader.running)
 308
 309         class Boom(Exception):
 310             pass
 311         mock_drop_uploader.side_effect = Boom()
 312
 313         basedir2 = "test_client.Basic.test_create_drop_uploader2"
 314         os.mkdir(basedir2)
 315         os.mkdir(os.path.join(basedir2, "private"))
 316         fileutil.write(os.path.join(basedir2, "tahoe.cfg"),
 317                        BASECONFIG +
 318                        "[drop_upload]\n" +
 319                        "enabled = true\n" +
 320                        "local.directory = " + local_dir_utf8 + "\n")
 321         fileutil.write(os.path.join(basedir2, "private", "drop_upload_dircap"), "URI:DIR2:blah")
 322         c2 = client.Client(basedir2)
 323         self.failUnlessRaises(KeyError, c2.getServiceNamed, 'drop-upload')
 324         self.failUnless([True for arg in mock_log_msg.call_args_list if "Boom" in repr(arg)],
 325                         mock_log_msg.call_args_list)
 326
 327
 328 def flush_but_dont_ignore(res):
 329     d = flushEventualQueue()
 330     def _done(ignored):
 331         return res
 332     d.addCallback(_done)
 333     return d
 334
 335 class Run(unittest.TestCase, testutil.StallMixin):
 336
 337     def setUp(self):
 338         self.sparent = service.MultiService()
 339         self.sparent.startService()
 340     def tearDown(self):
 341         d = self.sparent.stopService()
 342         d.addBoth(flush_but_dont_ignore)
 343         return d
 344
 345     def test_loadable(self):
 346         basedir = "test_client.Run.test_loadable"
 347         os.mkdir(basedir)
 348         dummy = "pb://wl74cyahejagspqgy4x5ukrvfnevlknt@127.0.0.1:58889/bogus"
 349         fileutil.write(os.path.join(basedir, "tahoe.cfg"), BASECONFIG_I % dummy)
 350         fileutil.write(os.path.join(basedir, client.Client.EXIT_TRIGGER_FILE), "")
 351         client.Client(basedir)
 352
 353     def test_reloadable(self):
 354         basedir = "test_client.Run.test_reloadable"
 355         os.mkdir(basedir)
 356         dummy = "pb://wl74cyahejagspqgy4x5ukrvfnevlknt@127.0.0.1:58889/bogus"
 357         fileutil.write(os.path.join(basedir, "tahoe.cfg"), BASECONFIG_I % dummy)
 358         c1 = client.Client(basedir)
 359         c1.setServiceParent(self.sparent)
 360
 361         # delay to let the service start up completely. I'm not entirely sure
 362         # this is necessary.
 363         d = self.stall(delay=2.0)
 364         d.addCallback(lambda res: c1.disownServiceParent())
 365         # the cygwin buildslave seems to need more time to let the old
 366         # service completely shut down. When delay=0.1, I saw this test fail,
 367         # probably due to the logport trying to reclaim the old socket
 368         # number. This suggests that either we're dropping a Deferred
 369         # somewhere in the shutdown sequence, or that cygwin is just cranky.
 370         d.addCallback(self.stall, delay=2.0)
 371         def _restart(res):
 372             # TODO: pause for slightly over one second, to let
 373             # Client._check_exit_trigger poll the file once. That will exercise
 374             # another few lines. Then add another test in which we don't
 375             # update the file at all, and watch to see the node shutdown.
 376             # (To do this, use a modified node which overrides Node.shutdown(),
 377             # also change _check_exit_trigger to use it instead of a raw
 378             # reactor.stop, also instrument the shutdown event in an
 379             # attribute that we can check.)
 380             c2 = client.Client(basedir)
 381             c2.setServiceParent(self.sparent)
 382             return c2.disownServiceParent()
 383         d.addCallback(_restart)
 384         return d
 385
 386 class NodeMaker(testutil.ReallyEqualMixin, unittest.TestCase):
 387     def test_maker(self):
 388         basedir = "client/NodeMaker/maker"
 389         fileutil.make_dirs(basedir)
 390         fileutil.write(os.path.join(basedir, "tahoe.cfg"), BASECONFIG)
 391         c = client.Client(basedir)
 392
 393         n = c.create_node_from_uri("URI:CHK:6nmrpsubgbe57udnexlkiwzmlu:bjt7j6hshrlmadjyr7otq3dc24end5meo5xcr5xe5r663po6itmq:3:10:7277")
 394         self.failUnless(IFilesystemNode.providedBy(n))
 395         self.failUnless(IFileNode.providedBy(n))
 396         self.failUnless(IImmutableFileNode.providedBy(n))
 397         self.failIf(IMutableFileNode.providedBy(n))
 398         self.failIf(IDirectoryNode.providedBy(n))
 399         self.failUnless(n.is_readonly())
 400         self.failIf(n.is_mutable())
 401
 402         # Testing #1679. There was a bug that would occur when downloader was
 403         # downloading the same readcap more than once concurrently, so the
 404         # filenode object was cached, and there was a failure from one of the
 405         # servers in one of the download attempts. No subsequent download
 406         # attempt would attempt to use that server again, which would lead to
 407         # the file being undownloadable until the gateway was restarted. The
 408         # current fix for this (hopefully to be superceded by a better fix
 409         # eventually) is to prevent re-use of filenodes, so the NodeMaker is
 410         # hereby required *not* to cache and re-use filenodes for CHKs.
 411         other_n = c.create_node_from_uri("URI:CHK:6nmrpsubgbe57udnexlkiwzmlu:bjt7j6hshrlmadjyr7otq3dc24end5meo5xcr5xe5r663po6itmq:3:10:7277")
 412         self.failIf(n is other_n, (n, other_n))
 413
 414         n = c.create_node_from_uri("URI:LIT:n5xgk")
 415         self.failUnless(IFilesystemNode.providedBy(n))
 416         self.failUnless(IFileNode.providedBy(n))
 417         self.failUnless(IImmutableFileNode.providedBy(n))
 418         self.failIf(IMutableFileNode.providedBy(n))
 419         self.failIf(IDirectoryNode.providedBy(n))
 420         self.failUnless(n.is_readonly())
 421         self.failIf(n.is_mutable())
 422
 423         n = c.create_node_from_uri("URI:SSK:n6x24zd3seu725yluj75q5boaa:mm6yoqjhl6ueh7iereldqxue4nene4wl7rqfjfybqrehdqmqskvq")
 424         self.failUnless(IFilesystemNode.providedBy(n))
 425         self.failUnless(IFileNode.providedBy(n))
 426         self.failIf(IImmutableFileNode.providedBy(n))
 427         self.failUnless(IMutableFileNode.providedBy(n))
 428         self.failIf(IDirectoryNode.providedBy(n))
 429         self.failIf(n.is_readonly())
 430         self.failUnless(n.is_mutable())
 431
 432         n = c.create_node_from_uri("URI:SSK-RO:b7sr5qsifnicca7cbk3rhrhbvq:mm6yoqjhl6ueh7iereldqxue4nene4wl7rqfjfybqrehdqmqskvq")
 433         self.failUnless(IFilesystemNode.providedBy(n))
 434         self.failUnless(IFileNode.providedBy(n))
 435         self.failIf(IImmutableFileNode.providedBy(n))
 436         self.failUnless(IMutableFileNode.providedBy(n))
 437         self.failIf(IDirectoryNode.providedBy(n))
 438         self.failUnless(n.is_readonly())
 439         self.failUnless(n.is_mutable())
 440
 441         n = c.create_node_from_uri("URI:DIR2:n6x24zd3seu725yluj75q5boaa:mm6yoqjhl6ueh7iereldqxue4nene4wl7rqfjfybqrehdqmqskvq")
 442         self.failUnless(IFilesystemNode.providedBy(n))
 443         self.failIf(IFileNode.providedBy(n))
 444         self.failIf(IImmutableFileNode.providedBy(n))
 445         self.failIf(IMutableFileNode.providedBy(n))
 446         self.failUnless(IDirectoryNode.providedBy(n))
 447         self.failIf(n.is_readonly())
 448         self.failUnless(n.is_mutable())
 449
 450         n = c.create_node_from_uri("URI:DIR2-RO:b7sr5qsifnicca7cbk3rhrhbvq:mm6yoqjhl6ueh7iereldqxue4nene4wl7rqfjfybqrehdqmqskvq")
 451         self.failUnless(IFilesystemNode.providedBy(n))
 452         self.failIf(IFileNode.providedBy(n))
 453         self.failIf(IImmutableFileNode.providedBy(n))
 454         self.failIf(IMutableFileNode.providedBy(n))
 455         self.failUnless(IDirectoryNode.providedBy(n))
 456         self.failUnless(n.is_readonly())
 457         self.failUnless(n.is_mutable())
 458
 459         unknown_rw = "lafs://from_the_future"
 460         unknown_ro = "lafs://readonly_from_the_future"
 461         n = c.create_node_from_uri(unknown_rw, unknown_ro)
 462         self.failUnless(IFilesystemNode.providedBy(n))
 463         self.failIf(IFileNode.providedBy(n))
 464         self.failIf(IImmutableFileNode.providedBy(n))
 465         self.failIf(IMutableFileNode.providedBy(n))
 466         self.failIf(IDirectoryNode.providedBy(n))
 467         self.failUnless(n.is_unknown())
 468         self.failUnlessReallyEqual(n.get_uri(), unknown_rw)
 469         self.failUnlessReallyEqual(n.get_write_uri(), unknown_rw)
 470         self.failUnlessReallyEqual(n.get_readonly_uri(), "ro." + unknown_ro)
 471
 472         # Note: it isn't that we *intend* to deploy non-ASCII caps in
 473         # the future, it is that we want to make sure older Tahoe-LAFS
 474         # versions wouldn't choke on them if we were to do so. See
 475         # #1051 and wiki:NewCapDesign for details.
 476         unknown_rw = u"lafs://from_the_future_rw_\u263A".encode('utf-8')
 477         unknown_ro = u"lafs://readonly_from_the_future_ro_\u263A".encode('utf-8')
 478         n = c.create_node_from_uri(unknown_rw, unknown_ro)
 479         self.failUnless(IFilesystemNode.providedBy(n))
 480         self.failIf(IFileNode.providedBy(n))
 481         self.failIf(IImmutableFileNode.providedBy(n))
 482         self.failIf(IMutableFileNode.providedBy(n))
 483         self.failIf(IDirectoryNode.providedBy(n))
 484         self.failUnless(n.is_unknown())
 485         self.failUnlessReallyEqual(n.get_uri(), unknown_rw)
 486         self.failUnlessReallyEqual(n.get_write_uri(), unknown_rw)
 487         self.failUnlessReallyEqual(n.get_readonly_uri(), "ro." + unknown_ro)