Merge branch 'master' into 3544.furls-not-bytes-maybe

.pre-commit-config.yaml

@@ -1,9 +1,10 @@
 repos:
-  - repo: local
+  - repo: "local"
     hooks:
-    - id: codechecks
+    - id: "codechecks"
-      name: codechecks
+      name: "codechecks"
       stages: ["push"]
+      language: "system"
+      files: ".py$"
       entry: "tox -e codechecks"
-      language: system
+      pass_filenames: true
-      pass_filenames: false

Makefile

@@ -13,8 +13,6 @@ MAKEFLAGS += --warn-undefined-variables
 MAKEFLAGS += --no-builtin-rules
 
 # Local target variables
-VCS_HOOK_SAMPLES=$(wildcard .git/hooks/*.sample)
-VCS_HOOKS=$(VCS_HOOK_SAMPLES:%.sample=%)
 PYTHON=python
 export PYTHON
 PYFLAKES=flake8
@@ -31,15 +29,6 @@ TEST_SUITE=allmydata
 default:
 	@echo "no default target"
 
-.PHONY: install-vcs-hooks
-## Install the VCS hooks to run linters on commit and all tests on push
-install-vcs-hooks: .git/hooks/pre-commit .git/hooks/pre-push
-.PHONY: uninstall-vcs-hooks
-## Remove the VCS hooks
-uninstall-vcs-hooks: .tox/create-venvs.log
-	"./$(dir $(<))py36/bin/pre-commit" uninstall || true
-	"./$(dir $(<))py36/bin/pre-commit" uninstall -t pre-push || true
-
 .PHONY: test
 ## Run all tests and code reports
 test: .tox/create-venvs.log
@@ -215,7 +204,7 @@ clean:
 	rm -f *.pkg
 
 .PHONY: distclean
-distclean: clean uninstall-vcs-hooks
+distclean: clean
 	rm -rf src/*.egg-info
 	rm -f src/allmydata/_version.py
 	rm -f src/allmydata/_appname.py
@@ -261,6 +250,3 @@ src/allmydata/_version.py:
 
 .tox/create-venvs.log: tox.ini setup.py
 	tox --notest -p all | tee -a "$(@)"
-
-$(VCS_HOOKS): .tox/create-venvs.log .pre-commit-config.yaml
-	"./$(dir $(<))py36/bin/pre-commit" install --hook-type $(@:.git/hooks/%=%)

docs/configuration.rst

@@ -398,13 +398,13 @@ This section controls *when* Tor and I2P are used. The ``[tor]`` and
 ``[i2p]`` sections (described later) control *how* Tor/I2P connections are
 managed.
 
-All Tahoe nodes need to make a connection to the Introducer; the ``[client]
+All Tahoe nodes need to make a connection to the Introducer; the
-introducer.furl`` setting (described below) indicates where the Introducer
+``private/introducers.yaml`` file (described below) configures where one or more
-lives. Tahoe client nodes must also make connections to storage servers:
+Introducers live. Tahoe client nodes must also make connections to storage
-these targets are specified in announcements that come from the Introducer.
+servers: these targets are specified in announcements that come from the
-Both are expressed as FURLs (a Foolscap URL), which include a list of
+Introducer.  Both are expressed as FURLs (a Foolscap URL), which include a
-"connection hints". Each connection hint describes one (of perhaps many)
+list of "connection hints". Each connection hint describes one (of perhaps
-network endpoints where the service might live.
+many) network endpoints where the service might live.
 
 Connection hints include a type, and look like:
 
@@ -580,6 +580,8 @@ Client Configuration
 
 ``introducer.furl = (FURL string, mandatory)``
 
+    DEPRECATED.  See :ref:`introducer-definitions`.
+
     This FURL tells the client how to connect to the introducer. Each
     Tahoe-LAFS grid is defined by an introducer. The introducer's FURL is
     created by the introducer node and written into its private base
@@ -965,29 +967,28 @@ This section describes these other files.
   with as many people as possible, put the empty string (so that
   ``private/convergence`` is a zero-length file).
 
-Additional Introducer Definitions
+.. _introducer-definitions:
-=================================
 
-The ``private/introducers.yaml`` file defines additional Introducers. The
+Introducer Definitions
-first introducer is defined in ``tahoe.cfg``, in ``[client]
+======================
-introducer.furl``. To use two or more Introducers, choose a locally-unique
+
-"petname" for each one, then define their FURLs in
+The ``private/introducers.yaml`` file defines Introducers.
-``private/introducers.yaml`` like this::
+Choose a locally-unique "petname" for each one then define their FURLs in ``private/introducers.yaml`` like this::
 
   introducers:
     petname2:
-      furl: FURL2
+      furl: "FURL2"
     petname3:
-      furl: FURL3
+      furl: "FURL3"
 
 Servers will announce themselves to all configured introducers. Clients will
 merge the announcements they receive from all introducers. Nothing will
 re-broadcast an announcement (i.e. telling introducer 2 about something you
 heard from introducer 1).
 
-If you omit the introducer definitions from both ``tahoe.cfg`` and
+If you omit the introducer definitions from ``introducers.yaml``,
-``introducers.yaml``, the node will not use an Introducer at all. Such
+the node will not use an Introducer at all.
-"introducerless" clients must be configured with static servers (described
+Such "introducerless" clients must be configured with static servers (described
 below), or they will not be able to upload and download files.
 
 Static Server Definitions
@@ -1152,7 +1153,6 @@ a legal one.
   timeout.disconnect = 1800
 
   [client]
-  introducer.furl = pb://ok45ssoklj4y7eok5c3xkmj@tcp:tahoe.example:44801/ii3uumo
   helper.furl = pb://ggti5ssoklj4y7eok5c3xkmj@tcp:helper.tahoe.example:7054/kk8lhr
 
   [storage]
@@ -1163,6 +1163,11 @@ a legal one.
   [helper]
   enabled = True
 
+To be introduced to storage servers, here is a sample ``private/introducers.yaml`` which can be used in conjunction::
+
+  introducers:
+    examplegrid:
+      furl: "pb://ok45ssoklj4y7eok5c3xkmj@tcp:tahoe.example:44801/ii3uumo"
 
 Old Configuration Files
 =======================

docs/developer-guide.rst

@@ -5,23 +5,17 @@ Developer Guide
 Pre-commit Checks
 -----------------
 
-This project is configured for use with `pre-commit`_ to install `VCS/git hooks`_ which
+This project is configured for use with `pre-commit`_ to install `VCS/git hooks`_ which perform some static code analysis checks and other code checks to catch common errors.
-perform some static code analysis checks and other code checks to catch common errors
+These hooks can be configured to run before commits or pushes
-before each commit and to run the full self-test suite to find less obvious regressions
-before each push to a remote.
 
 For example::
 
-  tahoe-lafs $ make install-vcs-hooks
+  tahoe-lafs $ pre-commit install --hook-type pre-push
-  ...
-  + ./.tox//py36/bin/pre-commit install --hook-type pre-commit
-  pre-commit installed at .git/hooks/pre-commit
-  + ./.tox//py36/bin/pre-commit install --hook-type pre-push
   pre-commit installed at .git/hooks/pre-push
-  tahoe-lafs $ python -c "import pathlib; pathlib.Path('src/allmydata/tabbed.py').write_text('def foo():\\n\\tpass\\n')"
+  tahoe-lafs $ echo "undefined" > src/allmydata/undefined_name.py
-  tahoe-lafs $ git add src/allmydata/tabbed.py
+  tahoe-lafs $ git add src/allmydata/undefined_name.py
   tahoe-lafs $ git commit -a -m "Add a file that violates flake8"
-  ...
+  tahoe-lafs $ git push
   codechecks...............................................................Failed
   - hook id: codechecks
   - exit code: 1
@@ -30,58 +24,17 @@ For example::
   codechecks inst-nodeps: ...
   codechecks installed: ...
   codechecks run-test-pre: PYTHONHASHSEED='...'
-  codechecks run-test: commands[0] | flake8 src static misc setup.py
+  codechecks run-test: commands[0] | flake8 src/allmydata/undefined_name.py
-  src/allmydata/tabbed.py:2:1: W191 indentation contains tabs
+  src/allmydata/undefined_name.py:1:1: F821 undefined name 'undefined'
-  ERROR: InvocationError for command ./tahoe-lafs/.tox/codechecks/bin/flake8 src static misc setup.py (exited with code 1)
+  ERROR: InvocationError for command ./tahoe-lafs/.tox/codechecks/bin/flake8 src/allmydata/undefined_name.py (exited with code 1)
   ___________________________________ summary ____________________________________
   ERROR:   codechecks: commands failed
-  ...
 
 To uninstall::
 
-  tahoe-lafs $ make uninstall-vcs-hooks
+  tahoe-lafs $ pre-commit uninstall --hook-type pre-push
-  ...
-  + ./.tox/py36/bin/pre-commit uninstall
-  pre-commit uninstalled
-  + ./.tox/py36/bin/pre-commit uninstall -t pre-push
   pre-push uninstalled
 
-Note that running the full self-test suite takes several minutes so expect pushing to
-take some time.  If you can't or don't want to wait for the hooks in some cases, use the
-``--no-verify`` option to ``$ git commit ...`` or ``$ git push ...``.  Alternatively,
-see the `pre-commit`_ documentation and CLI help output and use the committed
-`pre-commit configuration`_ as a starting point to write a local, uncommitted
-``../.pre-commit-config.local.yaml`` configuration to use instead.  For example::
-
-  tahoe-lafs $ ./.tox/py36/bin/pre-commit --help
-  tahoe-lafs $ ./.tox/py36/bin/pre-commit instll --help
-  tahoe-lafs $ cp  "./.pre-commit-config.yaml" "./.pre-commit-config.local.yaml"
-  tahoe-lafs $ editor "./.pre-commit-config.local.yaml"
-  ...
-  tahoe-lafs $ ./.tox/py36/bin/pre-commit install -c "./.pre-commit-config.local.yaml" -t pre-push
-  pre-commit installed at .git/hooks/pre-push
-  tahoe-lafs $ git commit -a -m "Add a file that violates flake8"
-  [3398.pre-commit 29f8f43d2] Add a file that violates flake8
-   1 file changed, 2 insertions(+)
-   create mode 100644 src/allmydata/tabbed.py
-  tahoe-lafs $ git push
-  ...
-  codechecks...............................................................Failed
-  - hook id: codechecks
-  - exit code: 1
-
-  GLOB sdist-make: ./tahoe-lafs/setup.py
-  codechecks inst-nodeps: ...
-  codechecks installed: ...
-  codechecks run-test-pre: PYTHONHASHSEED='...'
-  codechecks run-test: commands[0] | flake8 src static misc setup.py
-  src/allmydata/tabbed.py:2:1: W191 indentation contains tabs
-  ERROR: InvocationError for command ./tahoe-lafs/.tox/codechecks/bin/flake8 src static misc setup.py (exited with code 1)
-  ___________________________________ summary ____________________________________
-  ERROR:   codechecks: commands failed
-  ...
-
-  error: failed to push some refs to 'github.com:jaraco/tahoe-lafs.git'
 
 
 .. _`pre-commit`: https://pre-commit.com

docs/historical/configuration.rst

@@ -20,7 +20,7 @@ Config setting                   File                                 Comment
 ``[node]log_gatherer.furl``      ``BASEDIR/log_gatherer.furl``        (one per line)
 ``[node]timeout.keepalive``      ``BASEDIR/keepalive_timeout``
 ``[node]timeout.disconnect``     ``BASEDIR/disconnect_timeout``
-``[client]introducer.furl``      ``BASEDIR/introducer.furl``
+                                 ``BASEDIR/introducer.furl``          ``BASEDIR/private/introducers.yaml``
 ``[client]helper.furl``          ``BASEDIR/helper.furl``
 ``[client]key_generator.furl``   ``BASEDIR/key_generator.furl``
 ``[client]stats_gatherer.furl``  ``BASEDIR/stats_gatherer.furl``

docs/running.rst

@@ -65,9 +65,9 @@ Running a Client
 To construct a client node, run “``tahoe create-client``”, which will create
 ``~/.tahoe`` to be the node's base directory. Acquire the ``introducer.furl``
 (see below if you are running your own introducer, or use the one from the
-`TestGrid page`_), and paste it after ``introducer.furl =`` in the
+`TestGrid page`_), and write it to ``~/.tahoe/private/introducers.yaml``
-``[client]`` section of ``~/.tahoe/tahoe.cfg``. Then use “``tahoe run
+(see :ref:`introducer-definitions`). Then use “``tahoe run ~/.tahoe``”.
-~/.tahoe``”. After that, the node should be off and running. The first thing
+After that, the node should be off and running. The first thing
 it will do is connect to the introducer and get itself connected to all other
 nodes on the grid.
 

integration/test_tor.py

@@ -1,7 +1,6 @@
 from __future__ import print_function
 
 import sys
-from os import mkdir
 from os.path import join
 
 import pytest
@@ -9,6 +8,14 @@ import pytest_twisted
 
 import util
 
+from twisted.python.filepath import (
+    FilePath,
+)
+
+from allmydata.test.common import (
+    write_introducer,
+)
+
 # see "conftest.py" for the fixtures (e.g. "tor_network")
 
 # XXX: Integration tests that involve Tor do not run reliably on
@@ -66,12 +73,12 @@ def test_onion_service_storage(reactor, request, temp_dir, flog_gatherer, tor_ne
 
 @pytest_twisted.inlineCallbacks
 def _create_anonymous_node(reactor, name, control_port, request, temp_dir, flog_gatherer, tor_network, introducer_furl):
-    node_dir = join(temp_dir, name)
+    node_dir = FilePath(temp_dir).child(name)
     web_port = "tcp:{}:interface=localhost".format(control_port + 2000)
 
     if True:
-        print("creating", node_dir)
+        print("creating", node_dir.path)
-        mkdir(node_dir)
+        node_dir.makedirs()
         proto = util._DumpOutputProtocol(None)
         reactor.spawnProcess(
             proto,
@@ -84,12 +91,15 @@ def _create_anonymous_node(reactor, name, control_port, request, temp_dir, flog_
                 '--hide-ip',
                 '--tor-control-port', 'tcp:localhost:{}'.format(control_port),
                 '--listen', 'tor',
-                node_dir,
+                node_dir.path,
             )
         )
         yield proto.done
 
-    with open(join(node_dir, 'tahoe.cfg'), 'w') as f:
+
+    # Which services should this client connect to?
+    write_introducer(node_dir, "default", introducer_furl)
+    with node_dir.child('tahoe.cfg').open('w') as f:
         f.write('''
 [node]
 nickname = %(name)s
@@ -105,15 +115,12 @@ onion = true
 onion.private_key_file = private/tor_onion.privkey
 
 [client]
-# Which services should this client connect to?
-introducer.furl = %(furl)s
 shares.needed = 1
 shares.happy = 1
 shares.total = 2
 
 ''' % {
     'name': name,
-    'furl': introducer_furl,
     'web_port': web_port,
     'log_furl': flog_gatherer,
     'control_port': control_port,
@@ -121,5 +128,5 @@ shares.total = 2
 })
 
     print("running")
-    yield util._run_node(reactor, node_dir, request, None)
+    yield util._run_node(reactor, node_dir.path, request, None)
     print("okay, launched")

misc/coding_tools/check-debugging.py

@@ -11,8 +11,12 @@ umids = {}
 
 for starting_point in sys.argv[1:]:
     for root, dirs, files in os.walk(starting_point):
-        for fn in [f for f in files if f.endswith(".py")]:
+        for f in files:
-            fn = os.path.join(root, fn)
+            if not f.endswith(".py"):
+                continue
+            if f == "check-debugging.py":
+                continue
+            fn = os.path.join(root, f)
             for lineno,line in enumerate(open(fn, "r").readlines()):
                 lineno = lineno+1
                 mo = re.search(r"\.setDebugging\(True\)", line)

newsfragments/3504.configuration

@@ -0,0 +1 @@
+The ``[client]introducer.furl`` configuration item is now deprecated in favor of the ``private/introducers.yaml`` file.

newsfragments/3539.bugfix

@@ -0,0 +1 @@
+Certain implementation-internal weakref KeyErrors are now handled and should no longer cause user-initiated operations to fail.

src/allmydata/client.py

@@ -3,7 +3,6 @@ from past.builtins import unicode
 import os, stat, time, weakref
 from base64 import urlsafe_b64encode
 from functools import partial
-from errno import ENOENT, EPERM
 
 # On Python 2 this will be the backported package:
 from configparser import NoSectionError
@@ -467,56 +466,17 @@ def create_introducer_clients(config, main_tub, _introducer_factory=None):
     # we return this list
     introducer_clients = []
 
-    introducers_yaml_filename = config.get_private_path("introducers.yaml")
+    introducers = config.get_introducer_configuration()
-    introducers_filepath = FilePath(introducers_yaml_filename)
 
-    try:
+    for petname, (furl, cache_path) in introducers.items():
-        with introducers_filepath.open() as f:
-            introducers_yaml = yamlutil.safe_load(f)
-            if introducers_yaml is None:
-                raise EnvironmentError(
-                    EPERM,
-                    "Can't read '{}'".format(introducers_yaml_filename),
-                    introducers_yaml_filename,
-                )
-            introducers = introducers_yaml.get("introducers", {})
-            log.msg(
-                "found {} introducers in private/introducers.yaml".format(
-                    len(introducers),
-                )
-            )
-    except EnvironmentError as e:
-        if e.errno != ENOENT:
-            raise
-        introducers = {}
-
-    if "default" in introducers.keys():
-        raise ValueError(
-            "'default' introducer furl cannot be specified in introducers.yaml;"
-            " please fix impossible configuration."
-        )
-
-    # read furl from tahoe.cfg
-    tahoe_cfg_introducer_furl = config.get_config("client", "introducer.furl", None)
-    if tahoe_cfg_introducer_furl == "None":
-        raise ValueError(
-            "tahoe.cfg has invalid 'introducer.furl = None':"
-            " to disable it, use 'introducer.furl ='"
-            " or omit the key entirely"
-        )
-    if tahoe_cfg_introducer_furl:
-        introducers[u'default'] = {'furl':tahoe_cfg_introducer_furl}
-
-    for petname, introducer in introducers.items():
-        introducer_cache_filepath = FilePath(config.get_private_path("introducer_{}_cache.yaml".format(petname)))
         ic = _introducer_factory(
             main_tub,
-            introducer['furl'].encode("ascii"),
+            furl.encode("ascii"),
             config.nickname,
             str(allmydata.__full_version__),
             str(_Client.OLDEST_SUPPORTED_VERSION),
             partial(_sequencer, config),
-            introducer_cache_filepath,
+            cache_path,
         )
         introducer_clients.append(ic)
     return introducer_clients
@@ -1100,7 +1060,7 @@ class _Client(node.Node, pollmixin.PollMixin):
             if accountfile:
                 accountfile = self.config.get_config_path(accountfile)
             accounturl = self.config.get_config("sftpd", "accounts.url", None)
-            sftp_portstr = self.config.get_config("sftpd", "port", "8022")
+            sftp_portstr = self.config.get_config("sftpd", "port", "tcp:8022")
             pubkey_file = self.config.get_config("sftpd", "host_pubkey_file")
             privkey_file = self.config.get_config("sftpd", "host_privkey_file")
 

src/allmydata/frontends/sftpd.py

@@ -1975,6 +1975,8 @@ class Dispatcher(object):
 
 
 class SFTPServer(service.MultiService):
+    name = "frontend:sftp"
+
     def __init__(self, client, accountfile, accounturl,
                  sftp_portstr, pubkey_file, privkey_file):
         precondition(isinstance(accountfile, (unicode, NoneType)), accountfile)

src/allmydata/node.py

@@ -20,6 +20,8 @@ import re
 import types
 import errno
 from base64 import b32decode, b32encode
+from errno import ENOENT, EPERM
+from warnings import warn
 
 import attr
 
@@ -41,6 +43,9 @@ from allmydata.util import fileutil, iputil
 from allmydata.util.fileutil import abspath_expanduser_unicode
 from allmydata.util.encodingutil import get_filesystem_encoding, quote_output
 from allmydata.util import configutil
+from allmydata.util.yamlutil import (
+    safe_load,
+)
 
 from . import (
     __full_version__,
@@ -482,6 +487,97 @@ class _Config(object):
             os.path.join(self._basedir, *args)
         )
 
+    def get_introducer_configuration(self):
+        """
+        Get configuration for introducers.
+
+        :return {unicode: (unicode, FilePath)}: A mapping from introducer
+            petname to a tuple of the introducer's fURL and local cache path.
+        """
+        introducers_yaml_filename = self.get_private_path("introducers.yaml")
+        introducers_filepath = FilePath(introducers_yaml_filename)
+
+        def get_cache_filepath(petname):
+            return FilePath(
+                self.get_private_path("introducer_{}_cache.yaml".format(petname)),
+            )
+
+        try:
+            with introducers_filepath.open() as f:
+                introducers_yaml = safe_load(f)
+                if introducers_yaml is None:
+                    raise EnvironmentError(
+                        EPERM,
+                        "Can't read '{}'".format(introducers_yaml_filename),
+                        introducers_yaml_filename,
+                    )
+                introducers = {
+                    petname: config["furl"]
+                    for petname, config
+                    in introducers_yaml.get("introducers", {}).items()
+                }
+                non_strs = list(
+                    k
+                    for k
+                    in introducers.keys()
+                    if not isinstance(k, str)
+                )
+                if non_strs:
+                    raise TypeError(
+                        "Introducer petnames {!r} should have been str".format(
+                            non_strs,
+                        ),
+                    )
+                non_strs = list(
+                    v
+                    for v
+                    in introducers.values()
+                    if not isinstance(v, str)
+                )
+                if non_strs:
+                    raise TypeError(
+                        "Introducer fURLs {!r} should have been str".format(
+                            non_strs,
+                        ),
+                    )
+                log.msg(
+                    "found {} introducers in {!r}".format(
+                        len(introducers),
+                        introducers_yaml_filename,
+                    )
+                )
+        except EnvironmentError as e:
+            if e.errno != ENOENT:
+                raise
+            introducers = {}
+
+        # supported the deprecated [client]introducer.furl item in tahoe.cfg
+        tahoe_cfg_introducer_furl = self.get_config("client", "introducer.furl", None)
+        if tahoe_cfg_introducer_furl == "None":
+            raise ValueError(
+                "tahoe.cfg has invalid 'introducer.furl = None':"
+                " to disable it omit the key entirely"
+            )
+        if tahoe_cfg_introducer_furl:
+            warn(
+                "tahoe.cfg [client]introducer.furl is deprecated; "
+                "use private/introducers.yaml instead.",
+                category=DeprecationWarning,
+                stacklevel=-1,
+            )
+            if "default" in introducers:
+                raise ValueError(
+                    "'default' introducer furl cannot be specified in tahoe.cfg and introducers.yaml;"
+                    " please fix impossible configuration."
+                )
+            introducers['default'] = tahoe_cfg_introducer_furl
+
+        return {
+            petname: (furl, get_cache_filepath(petname))
+            for (petname, furl)
+            in introducers.items()
+        }
+
 
 def create_tub_options(config):
     """

src/allmydata/nodemaker.py

@@ -66,9 +66,9 @@ class NodeMaker(object):
             memokey = b"I" + bigcap
         else:
             memokey = b"M" + bigcap
-        if memokey in self._node_cache:
+        try:
             node = self._node_cache[memokey]
-        else:
+        except KeyError:
             cap = uri.from_string(bigcap, deep_immutable=deep_immutable,
                                   name=name)
             node = self._create_from_single_cap(cap)

src/allmydata/scripts/common.py

@@ -4,14 +4,15 @@ import os, sys, urllib, textwrap
 import codecs
 from os.path import join
 
+from yaml import (
+    safe_dump,
+)
+
 # Python 2 compatibility
 from future.utils import PY2
 if PY2:
     from future.builtins import str  # noqa: F401
 
-# On Python 2 this will be the backported package:
-from configparser import NoSectionError
-
 from twisted.python import usage
 
 from allmydata.util.assertutil import precondition
@@ -115,24 +116,42 @@ class NoDefaultBasedirOptions(BasedirOptions):
 DEFAULT_ALIAS = u"tahoe"
 
 
+def write_introducer(basedir, petname, furl):
+    """
+    Overwrite the node's ``introducers.yaml`` with a file containing the given
+    introducer information.
+    """
+    if isinstance(furl, bytes):
+        furl = furl.decode("utf-8")
+    basedir.child(b"private").child(b"introducers.yaml").setContent(
+        safe_dump({
+            "introducers": {
+                petname: {
+                    "furl": furl,
+                },
+            },
+        }).encode("ascii"),
+    )
+
+
 def get_introducer_furl(nodedir, config):
     """
     :return: the introducer FURL for the given node (no matter if it's
         a client-type node or an introducer itself)
     """
+    for petname, (furl, cache) in config.get_introducer_configuration().items():
+        return furl
+
+    # We have no configured introducers.  Maybe this is running *on* the
+    # introducer?  Let's guess, sure why not.
     try:
-        introducer_furl = config.get('client', 'introducer.furl')
+        with open(join(nodedir, "private", "introducer.furl"), "r") as f:
-    except NoSectionError:
+            return f.read().strip()
-        # we're not a client; maybe this is running *on* the introducer?
+    except IOError:
-        try:
+        raise Exception(
-            with open(join(nodedir, "private", "introducer.furl"), "r") as f:
+            "Can't find introducer FURL in tahoe.cfg nor "
-                introducer_furl = f.read().strip()
+            "{}/private/introducer.furl".format(nodedir)
-        except IOError:
+        )
-            raise Exception(
-                "Can't find introducer FURL in tahoe.cfg nor "
-                "{}/private/introducer.furl".format(nodedir)
-            )
-    return introducer_furl
 
 
 def get_aliases(nodedir):

src/allmydata/scripts/create_node.py

@@ -5,11 +5,20 @@ import json
 
 from twisted.internet import reactor, defer
 from twisted.python.usage import UsageError
-from allmydata.scripts.common import BasedirOptions, NoDefaultBasedirOptions
+from twisted.python.filepath import (
+    FilePath,
+)
+
+from allmydata.scripts.common import (
+    BasedirOptions,
+    NoDefaultBasedirOptions,
+    write_introducer,
+)
 from allmydata.scripts.default_nodedir import _default_nodedir
 from allmydata.util.assertutil import precondition
 from allmydata.util.encodingutil import listdir_unicode, argv_to_unicode, quote_local_unicode_path, get_io_encoding
 from allmydata.util import fileutil, i2p_provider, iputil, tor_provider
+
 from wormhole import wormhole
 
 
@@ -299,12 +308,15 @@ def write_node_config(c, config):
 
 
 def write_client_config(c, config):
-    # note, config can be a plain dict, it seems -- see
+    introducer = config.get("introducer", None)
-    # test_configutil.py in test_create_client_config
+    if introducer is not None:
+        write_introducer(
+            FilePath(config["basedir"]),
+            "default",
+            introducer,
+        )
+
     c.write("[client]\n")
-    c.write("# Which services should this client connect to?\n")
-    introducer = config.get("introducer", None) or ""
-    c.write("introducer.furl = %s\n" % introducer)
     c.write("helper.furl =\n")
     c.write("#stats_gatherer.furl =\n")
     c.write("\n")
@@ -437,8 +449,11 @@ def create_node(config):
 
     print("Node created in %s" % quote_local_unicode_path(basedir), file=out)
     tahoe_cfg = quote_local_unicode_path(os.path.join(basedir, "tahoe.cfg"))
+    introducers_yaml = quote_local_unicode_path(
+        os.path.join(basedir, "private", "introducers.yaml"),
+    )
     if not config.get("introducer", ""):
-        print(" Please set [client]introducer.furl= in %s!" % tahoe_cfg, file=out)
+        print(" Please add introducers to %s!" % (introducers_yaml,), file=out)
         print(" The node cannot connect to a grid without it.", file=out)
     if not config.get("nickname", ""):
         print(" Please set [node]nickname= in %s" % tahoe_cfg, file=out)

src/allmydata/scripts/tahoe_invite.py

@@ -1,16 +1,15 @@
 from __future__ import print_function
 
 import json
-from os.path import join
 
 from twisted.python import usage
 from twisted.internet import defer, reactor
 
 from wormhole import wormhole
 
-from allmydata.util import configutil
 from allmydata.util.encodingutil import argv_to_abspath
 from allmydata.scripts.common import get_default_nodedir, get_introducer_furl
+from allmydata.node import read_config
 
 
 class InviteOptions(usage.Options):
@@ -77,7 +76,7 @@ def invite(options):
         basedir = argv_to_abspath(options.parent['node-directory'])
     else:
         basedir = get_default_nodedir()
-    config = configutil.get_config(join(basedir, 'tahoe.cfg'))
+    config = read_config(basedir, u"")
     out = options.stdout
     err = options.stderr
 

src/allmydata/test/check_memory.py

@@ -8,6 +8,9 @@ if PY2:
     from future.builtins import str  # noqa: F401
 from six.moves import cStringIO as StringIO
 
+from twisted.python.filepath import (
+    FilePath,
+)
 from twisted.internet import defer, reactor, protocol, error
 from twisted.application import service, internet
 from twisted.web import client as tw_client
@@ -21,6 +24,10 @@ from allmydata.util import fileutil, pollmixin
 from allmydata.util.fileutil import abspath_expanduser_unicode
 from allmydata.util.encodingutil import get_filesystem_encoding
 
+from allmydata.scripts.common import (
+    write_introducer,
+)
+
 class StallableHTTPGetterDiscarder(tw_client.HTTPPageGetter, object):
     full_speed_ahead = False
     _bytes_so_far = 0
@@ -180,16 +187,18 @@ class SystemFramework(pollmixin.PollMixin):
         self.introducer_furl = self.introducer.introducer_url
 
     def make_nodes(self):
+        root = FilePath(self.testdir)
         self.nodes = []
         for i in range(self.numnodes):
-            nodedir = os.path.join(self.testdir, "node%d" % i)
+            nodedir = root.child("node%d" % (i,))
-            os.mkdir(nodedir)
+            private = nodedir.child("private")
-            f = open(os.path.join(nodedir, "tahoe.cfg"), "w")
+            private.makedirs()
-            f.write("[client]\n"
+            write_introducer(nodedir, "default", self.introducer_url)
-                    "introducer.furl = %s\n"
+            config = (
-                    "shares.happy = 1\n"
+                "[client]\n"
-                    "[storage]\n"
+                "shares.happy = 1\n"
-                    % (self.introducer_furl,))
+                "[storage]\n"
+            )
             # the only tests for which we want the internal nodes to actually
             # retain shares are the ones where somebody's going to download
             # them.
@@ -200,13 +209,13 @@ class SystemFramework(pollmixin.PollMixin):
                 # for these tests, we tell the storage servers to pretend to
                 # accept shares, but really just throw them out, since we're
                 # only testing upload and not download.
-                f.write("debug_discard = true\n")
+                config += "debug_discard = true\n"
             if self.mode in ("receive",):
                 # for this mode, the client-under-test gets all the shares,
                 # so our internal nodes can refuse requests
-                f.write("readonly = true\n")
+                config += "readonly = true\n"
-            f.close()
+            nodedir.child("tahoe.cfg").setContent(config)
-            c = client.Client(basedir=nodedir)
+            c = client.Client(basedir=nodedir.path)
             c.setServiceParent(self)
             self.nodes.append(c)
         # the peers will start running, eventually they will connect to each
@@ -235,16 +244,16 @@ this file are ignored.
         quiet = StringIO()
         create_node.create_node({'basedir': clientdir}, out=quiet)
         log.msg("DONE MAKING CLIENT")
+        write_introducer(clientdir, "default", self.introducer_furl)
         # now replace tahoe.cfg
         # set webport=0 and then ask the node what port it picked.
         f = open(os.path.join(clientdir, "tahoe.cfg"), "w")
         f.write("[node]\n"
                 "web.port = tcp:0:interface=127.0.0.1\n"
                 "[client]\n"
-                "introducer.furl = %s\n"
                 "shares.happy = 1\n"
                 "[storage]\n"
-                % (self.introducer_furl,))
+        )
 
         if self.mode in ("upload-self", "receive"):
             # accept and store shares, to trigger the memory consumption bugs

src/allmydata/test/cli/test_invite.py

@@ -8,7 +8,9 @@ from twisted.internet import defer
 from ..common_util import run_cli
 from ..no_network import GridTestMixin
 from .common import CLITestMixin
-
+from ...client import (
+    read_config,
+)
 
 class _FakeWormhole(object):
 
@@ -81,9 +83,19 @@ class Join(GridTestMixin, CLITestMixin, unittest.TestCase):
             )
 
             self.assertEqual(0, rc)
+
+            config = read_config(node_dir, u"")
+            self.assertIn(
+                "pb://foo",
+                set(
+                    furl
+                    for (furl, cache)
+                    in config.get_introducer_configuration().values()
+                ),
+            )
+
             with open(join(node_dir, 'tahoe.cfg'), 'r') as f:
                 config = f.read()
-            self.assertIn("pb://foo", config)
             self.assertIn(u"somethinghopefullyunique", config)
 
     @defer.inlineCallbacks

src/allmydata/test/common.py

@@ -81,6 +81,9 @@ from allmydata.client import (
     config_from_string,
     create_client_from_config,
 )
+from allmydata.scripts.common import (
+    write_introducer,
+    )
 
 from ..crypto import (
     ed25519,
@@ -221,8 +224,8 @@ class UseNode(object):
     """
     plugin_config = attr.ib()
     storage_plugin = attr.ib()
-    basedir = attr.ib()
+    basedir = attr.ib(validator=attr.validators.instance_of(FilePath))
-    introducer_furl = attr.ib()
+    introducer_furl = attr.ib(validator=attr.validators.instance_of(bytes))
     node_config = attr.ib(default=attr.Factory(dict))
 
     config = attr.ib(default=None)
@@ -246,6 +249,11 @@ class UseNode(object):
     config=format_config_items(self.plugin_config),
 )
 
+        write_introducer(
+            self.basedir,
+            "default",
+            self.introducer_furl,
+        )
         self.config = config_from_string(
             self.basedir.asTextMode().path,
             "tub.port",
@@ -254,11 +262,9 @@ class UseNode(object):
 {node_config}
 
 [client]
-introducer.furl = {furl}
 storage.plugins = {storage_plugin}
 {plugin_config_section}
 """.format(
-    furl=self.introducer_furl,
     storage_plugin=self.storage_plugin,
     node_config=format_config_items(self.node_config),
     plugin_config_section=plugin_config_section,

src/allmydata/test/data/openssh-rsa-2048.pub.txt

@@ -0,0 +1 @@
+ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDx5JfaPwE2wfXIQcmlGte9EPAbrTmHPGOF/PuZ71XPa3mZTHMQQuc959gmLxupmcc5o4jYe8VTwT6bbNl6YM+HmCvL3XVH0BqdM2lpKCTB/WzSAyFUv8gSjQVXekRm9wF69tZkPrudqutTLhqXU5ESiUzfhU+CxHQW+kAf10Yd9R68V1f8jkuWjEoeVfCltj7O5fRlpouoTXn83MUAXB3J/wDjpjnjp2PxvXL2x5aCHtzd1WCGEmtWbHZvRA1a0EE233zfXNHg4xLd3ycUqAxoRlCcC230itUBXtr4qgDMzRdsL+HGWrcJ+4yezlQj+l8mc7vi5shNT7HDRfvi/rE7 exarkun@baryon

src/allmydata/test/data/openssh-rsa-2048.txt

@@ -0,0 +1,27 @@
+-----BEGIN OPENSSH PRIVATE KEY-----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+-----END OPENSSH PRIVATE KEY-----

src/allmydata/test/strategies.py

@@ -0,0 +1,111 @@
+"""
+Hypothesis strategies use for testing Tahoe-LAFS.
+"""
+
+from hypothesis.strategies import (
+    one_of,
+    builds,
+    binary,
+)
+
+from ..uri import (
+    WriteableSSKFileURI,
+    WriteableMDMFFileURI,
+    DirectoryURI,
+    MDMFDirectoryURI,
+)
+
+def write_capabilities():
+    """
+    Build ``IURI`` providers representing all kinds of write capabilities.
+    """
+    return one_of([
+        ssk_capabilities(),
+        mdmf_capabilities(),
+        dir2_capabilities(),
+        dir2_mdmf_capabilities(),
+    ])
+
+
+def ssk_capabilities():
+    """
+    Build ``WriteableSSKFileURI`` instances.
+    """
+    return builds(
+        WriteableSSKFileURI,
+        ssk_writekeys(),
+        ssk_fingerprints(),
+    )
+
+
+def _writekeys(size=16):
+    """
+    Build ``bytes`` representing write keys.
+    """
+    return binary(min_size=size, max_size=size)
+
+
+def ssk_writekeys():
+    """
+    Build ``bytes`` representing SSK write keys.
+    """
+    return _writekeys()
+
+
+def _fingerprints(size=32):
+    """
+    Build ``bytes`` representing fingerprints.
+    """
+    return binary(min_size=size, max_size=size)
+
+
+def ssk_fingerprints():
+    """
+    Build ``bytes`` representing SSK fingerprints.
+    """
+    return _fingerprints()
+
+
+def mdmf_capabilities():
+    """
+    Build ``WriteableMDMFFileURI`` instances.
+    """
+    return builds(
+        WriteableMDMFFileURI,
+        mdmf_writekeys(),
+        mdmf_fingerprints(),
+    )
+
+
+def mdmf_writekeys():
+    """
+    Build ``bytes`` representing MDMF write keys.
+    """
+    return _writekeys()
+
+
+def mdmf_fingerprints():
+    """
+    Build ``bytes`` representing MDMF fingerprints.
+    """
+    return _fingerprints()
+
+
+def dir2_capabilities():
+    """
+    Build ``DirectoryURI`` instances.
+    """
+    return builds(
+        DirectoryURI,
+        ssk_capabilities(),
+    )
+
+
+def dir2_mdmf_capabilities():
+    """
+    Build ``MDMFDirectoryURI`` instances.
+    """
+    return builds(
+        MDMFDirectoryURI,
+        mdmf_capabilities(),
+    )

src/allmydata/test/test_client.py

@@ -1,5 +1,4 @@
 import os, sys
-import mock
 from functools import (
     partial,
 )
@@ -12,6 +11,15 @@ from fixtures import (
     Fixture,
     TempDir,
 )
+
+from hypothesis import (
+    given,
+)
+from hypothesis.strategies import (
+    sampled_from,
+    booleans,
+)
+
 from eliot.testing import (
     capture_logging,
     assertHasAction,
@@ -39,6 +47,9 @@ from testtools.twistedsupport import (
 import allmydata
 import allmydata.util.log
 
+from allmydata.nodemaker import (
+    NodeMaker,
+)
 from allmydata.node import OldConfigError, UnescapedHashError, create_node_dir
 from allmydata.frontends.auth import NeedRootcapLookupScheme
 from allmydata import client
@@ -55,11 +66,15 @@ from allmydata.util import (
 from allmydata.util.fileutil import abspath_expanduser_unicode
 from allmydata.interfaces import IFilesystemNode, IFileNode, \
      IImmutableFileNode, IMutableFileNode, IDirectoryNode
+from allmydata.scripts.common import (
+    write_introducer,
+)
 from foolscap.api import flushEventualQueue
 import allmydata.test.common_util as testutil
 from .common import (
     EMPTY_CLIENT_CONFIG,
     SyncTestCase,
+    AsyncBrokenTestCase,
     UseTestPlugins,
     MemoryIntroducerClient,
     get_published_announcements,
@@ -69,16 +84,13 @@ from .matchers import (
     matches_storage_announcement,
     matches_furl,
 )
+from .strategies import (
+    write_capabilities,
+)
 
 SOME_FURL = "pb://abcde@nowhere/fake"
 
-BASECONFIG = ("[client]\n"
+BASECONFIG = "[client]\n"
-              "introducer.furl = \n"
-              )
-
-BASECONFIG_I = ("[client]\n"
-              "introducer.furl = %s\n"
-              )
 
 class Basic(testutil.ReallyEqualMixin, unittest.TestCase):
     def test_loadable(self):
@@ -120,14 +132,14 @@ class Basic(testutil.ReallyEqualMixin, unittest.TestCase):
 
         def write_config(s):
             config = ("[client]\n"
-                      "introducer.furl = %s\n" % s)
+                      "helper.furl = %s\n" % s)
             fileutil.write(os.path.join(basedir, "tahoe.cfg"), config)
 
         for s in should_fail:
             write_config(s)
             with self.assertRaises(UnescapedHashError) as ctx:
                 yield client.create_client(basedir)
-            self.assertIn("[client]introducer.furl", str(ctx.exception))
+            self.assertIn("[client]helper.furl", str(ctx.exception))
 
     def test_unreadable_config(self):
         if sys.platform == "win32":
@@ -419,19 +431,32 @@ class Basic(testutil.ReallyEqualMixin, unittest.TestCase):
         """
         configuration for sftpd results in it being started
         """
+        root = FilePath(self.mktemp())
+        root.makedirs()
+        accounts = root.child(b"sftp-accounts")
+        accounts.touch()
+
+        data = FilePath(__file__).sibling(b"data")
+        privkey = data.child(b"openssh-rsa-2048.txt")
+        pubkey = data.child(b"openssh-rsa-2048.pub.txt")
+
         basedir = u"client.Basic.test_ftp_create"
         create_node_dir(basedir, "testing")
         with open(os.path.join(basedir, "tahoe.cfg"), "w") as f:
-            f.write(
+            f.write((
                 '[sftpd]\n'
                 'enabled = true\n'
-                'accounts.file = foo\n'
+                'accounts.file = {}\n'
-                'host_pubkey_file = pubkey\n'
+                'host_pubkey_file = {}\n'
-                'host_privkey_file = privkey\n'
+                'host_privkey_file = {}\n'
-            )
+            ).format(accounts.path, pubkey.path, privkey.path))
-        with mock.patch('allmydata.frontends.sftpd.SFTPServer') as p:
+
-            yield client.create_client(basedir)
+        client_node = yield client.create_client(
-        self.assertTrue(p.called)
+            basedir,
+        )
+        sftp = client_node.getServiceNamed("frontend:sftp")
+        self.assertIs(sftp.parent, client_node)
+
 
     @defer.inlineCallbacks
     def test_ftp_auth_keyfile(self):
@@ -665,12 +690,13 @@ class AnonymousStorage(SyncTestCase):
         """
         If anonymous storage access is enabled then the client announces it.
         """
-        basedir = self.id()
+        basedir = FilePath(self.id())
-        os.makedirs(basedir + b"/private")
+        basedir.child("private").makedirs()
+        write_introducer(basedir, "someintroducer", SOME_FURL)
         config = client.config_from_string(
-            basedir,
+            basedir.path,
             "tub.port",
-            BASECONFIG_I % (SOME_FURL,) + (
+            BASECONFIG + (
                 "[storage]\n"
                 "enabled = true\n"
                 "anonymous = true\n"
@@ -684,7 +710,7 @@ class AnonymousStorage(SyncTestCase):
             get_published_announcements(node),
             MatchesListwise([
                 matches_storage_announcement(
-                    basedir,
+                    basedir.path,
                     anonymous=True,
                 ),
             ]),
@@ -696,12 +722,13 @@ class AnonymousStorage(SyncTestCase):
         If anonymous storage access is disabled then the client does not announce
         it nor does it write a fURL for it to beneath the node directory.
         """
-        basedir = self.id()
+        basedir = FilePath(self.id())
-        os.makedirs(basedir + b"/private")
+        basedir.child("private").makedirs()
+        write_introducer(basedir, "someintroducer", SOME_FURL)
         config = client.config_from_string(
-            basedir,
+            basedir.path,
             "tub.port",
-            BASECONFIG_I % (SOME_FURL,) + (
+            BASECONFIG + (
                 "[storage]\n"
                 "enabled = true\n"
                 "anonymous = false\n"
@@ -715,7 +742,7 @@ class AnonymousStorage(SyncTestCase):
             get_published_announcements(node),
             MatchesListwise([
                 matches_storage_announcement(
-                    basedir,
+                    basedir.path,
                     anonymous=False,
                 ),
             ]),
@@ -733,12 +760,12 @@ class AnonymousStorage(SyncTestCase):
         possible to reach the anonymous storage server via the originally
         published fURL.
         """
-        basedir = self.id()
+        basedir = FilePath(self.id())
-        os.makedirs(basedir + b"/private")
+        basedir.child("private").makedirs()
         enabled_config = client.config_from_string(
-            basedir,
+            basedir.path,
             "tub.port",
-            BASECONFIG_I % (SOME_FURL,) + (
+            BASECONFIG + (
                 "[storage]\n"
                 "enabled = true\n"
                 "anonymous = true\n"
@@ -760,9 +787,9 @@ class AnonymousStorage(SyncTestCase):
         )
 
         disabled_config = client.config_from_string(
-            basedir,
+            basedir.path,
             "tub.port",
-            BASECONFIG_I % (SOME_FURL,) + (
+            BASECONFIG + (
                 "[storage]\n"
                 "enabled = true\n"
                 "anonymous = false\n"
@@ -782,8 +809,8 @@ class IntroducerClients(unittest.TestCase):
 
     def test_invalid_introducer_furl(self):
         """
-        An introducer.furl of 'None' is invalid and causes
+        An introducer.furl of 'None' in the deprecated [client]introducer.furl
-        create_introducer_clients to fail.
+        field is invalid and causes `create_introducer_clients` to fail.
         """
         cfg = (
             "[client]\n"
@@ -948,20 +975,28 @@ class Run(unittest.TestCase, testutil.StallMixin):
 
     @defer.inlineCallbacks
     def test_loadable(self):
-        basedir = "test_client.Run.test_loadable"
+        """
-        os.mkdir(basedir)
+        A configuration consisting only of an introducer can be turned into a
+        client node.
+        """
+        basedir = FilePath("test_client.Run.test_loadable")
+        private = basedir.child("private")
+        private.makedirs()
         dummy = "pb://wl74cyahejagspqgy4x5ukrvfnevlknt@127.0.0.1:58889/bogus"
-        fileutil.write(os.path.join(basedir, "tahoe.cfg"), BASECONFIG_I % dummy)
+        write_introducer(basedir, "someintroducer", dummy)
-        fileutil.write(os.path.join(basedir, client._Client.EXIT_TRIGGER_FILE), "")
+        basedir.child("tahoe.cfg").setContent(BASECONFIG)
-        yield client.create_client(basedir)
+        basedir.child(client._Client.EXIT_TRIGGER_FILE).touch()
+        yield client.create_client(basedir.path)
 
     @defer.inlineCallbacks
     def test_reloadable(self):
-        basedir = "test_client.Run.test_reloadable"
+        basedir = FilePath("test_client.Run.test_reloadable")
-        os.mkdir(basedir)
+        private = basedir.child("private")
+        private.makedirs()
         dummy = "pb://wl74cyahejagspqgy4x5ukrvfnevlknt@127.0.0.1:58889/bogus"
-        fileutil.write(os.path.join(basedir, "tahoe.cfg"), BASECONFIG_I % dummy)
+        write_introducer(basedir, "someintroducer", dummy)
-        c1 = yield client.create_client(basedir)
+        basedir.child("tahoe.cfg").setContent(BASECONFIG)
+        c1 = yield client.create_client(basedir.path)
         c1.setServiceParent(self.sparent)
 
         # delay to let the service start up completely. I'm not entirely sure
@@ -983,11 +1018,102 @@ class Run(unittest.TestCase, testutil.StallMixin):
         # also change _check_exit_trigger to use it instead of a raw
         # reactor.stop, also instrument the shutdown event in an
         # attribute that we can check.)
-        c2 = yield client.create_client(basedir)
+        c2 = yield client.create_client(basedir.path)
         c2.setServiceParent(self.sparent)
         yield c2.disownServiceParent()
 
-class NodeMaker(testutil.ReallyEqualMixin, unittest.TestCase):
+class NodeMakerTests(testutil.ReallyEqualMixin, AsyncBrokenTestCase):
+
+    def _make_node_maker(self, mode, writecap, deep_immutable):
+        """
+        Create a callable which can create an ``IFilesystemNode`` provider for the
+        given cap.
+
+        :param unicode mode: The read/write combination to pass to
+            ``NodeMaker.create_from_cap``.  If it contains ``u"r"`` then a
+            readcap will be passed in.  If it contains ``u"w"`` then a
+            writecap will be passed in.
+
+        :param IURI writecap: The capability for which to create a node.
+
+        :param bool deep_immutable: Whether to request a "deep immutable" node
+            which forces the result to be an immutable ``IFilesystemNode`` (I
+            think -exarkun).
+        """
+        if writecap.is_mutable():
+            # It's just not a valid combination to have a mutable alongside
+            # deep_immutable = True.  It's easier to fix deep_immutable than
+            # writecap to clear up this conflict.
+            deep_immutable = False
+
+        if "r" in mode:
+            readcap = writecap.get_readonly().to_string()
+        else:
+            readcap = None
+        if "w" in mode:
+            writecap = writecap.to_string()
+        else:
+            writecap = None
+
+        nm = NodeMaker(
+            storage_broker=None,
+            secret_holder=None,
+            history=None,
+            uploader=None,
+            terminator=None,
+            default_encoding_parameters={u"k": 1, u"n": 1},
+            mutable_file_default=None,
+            key_generator=None,
+            blacklist=None,
+        )
+        return partial(
+            nm.create_from_cap,
+            writecap,
+            readcap,
+            deep_immutable,
+        )
+
+    @given(
+        mode=sampled_from(["w", "r", "rw"]),
+        writecap=write_capabilities(),
+        deep_immutable=booleans(),
+    )
+    def test_cached_result(self, mode, writecap, deep_immutable):
+        """
+        ``NodeMaker.create_from_cap`` returns the same object when called with the
+        same arguments.
+        """
+        make_node = self._make_node_maker(mode, writecap, deep_immutable)
+        original = make_node()
+        additional = make_node()
+
+        self.assertThat(
+            original,
+            Is(additional),
+        )
+
+    @given(
+        mode=sampled_from(["w", "r", "rw"]),
+        writecap=write_capabilities(),
+        deep_immutable=booleans(),
+    )
+    def test_cache_expired(self, mode, writecap, deep_immutable):
+        """
+        After the node object returned by an earlier call to
+        ``NodeMaker.create_from_cap`` has been garbage collected, a new call
+        to ``NodeMaker.create_from_cap`` returns a node object, maybe even a
+        new one although we can't really prove it.
+        """
+        make_node = self._make_node_maker(mode, writecap, deep_immutable)
+        make_node()
+        additional = make_node()
+        self.assertThat(
+            additional,
+            AfterPreprocessing(
+                lambda node: node.get_readonly_uri(),
+                Equals(writecap.get_readonly().to_string()),
+            ),
+        )
 
     @defer.inlineCallbacks
     def test_maker(self):
@@ -1122,12 +1248,18 @@ class StorageAnnouncementTests(SyncTestCase):
     """
     def setUp(self):
         super(StorageAnnouncementTests, self).setUp()
-        self.basedir = self.useFixture(TempDir()).path
+        self.basedir = FilePath(self.useFixture(TempDir()).path)
-        create_node_dir(self.basedir, u"")
+        create_node_dir(self.basedir.path, u"")
+        # Write an introducer configuration or we can't observer
+        # announcements.
+        write_introducer(self.basedir, "someintroducer", SOME_FURL)
 
 
     def get_config(self, storage_enabled, more_storage="", more_sections=""):
         return """
+[client]
+# Empty
+
 [node]
 tub.location = tcp:192.0.2.0:1234
 
@@ -1135,9 +1267,6 @@ tub.location = tcp:192.0.2.0:1234
 enabled = {storage_enabled}
 {more_storage}
 
-[client]
-introducer.furl = pb://abcde@nowhere/fake
-
 {more_sections}
 """.format(
     storage_enabled=storage_enabled,
@@ -1151,7 +1280,7 @@ introducer.furl = pb://abcde@nowhere/fake
         No storage announcement is published if storage is not enabled.
         """
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(storage_enabled=False),
         )
@@ -1173,7 +1302,7 @@ introducer.furl = pb://abcde@nowhere/fake
         storage is enabled.
         """
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(storage_enabled=True),
         )
@@ -1190,7 +1319,7 @@ introducer.furl = pb://abcde@nowhere/fake
                 # Match the following list (of one element) ...
                 MatchesListwise([
                     # The only element in the list ...
-                    matches_storage_announcement(self.basedir),
+                    matches_storage_announcement(self.basedir.path),
                 ]),
             )),
         )
@@ -1205,7 +1334,7 @@ introducer.furl = pb://abcde@nowhere/fake
 
         value = u"thing"
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(
                 storage_enabled=True,
@@ -1225,7 +1354,7 @@ introducer.furl = pb://abcde@nowhere/fake
                 get_published_announcements,
                 MatchesListwise([
                     matches_storage_announcement(
-                        self.basedir,
+                        self.basedir.path,
                         options=[
                             matches_dummy_announcement(
                                 u"tahoe-lafs-dummy-v1",
@@ -1246,7 +1375,7 @@ introducer.furl = pb://abcde@nowhere/fake
         self.useFixture(UseTestPlugins())
 
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(
                 storage_enabled=True,
@@ -1268,7 +1397,7 @@ introducer.furl = pb://abcde@nowhere/fake
                 get_published_announcements,
                 MatchesListwise([
                     matches_storage_announcement(
-                        self.basedir,
+                        self.basedir.path,
                         options=[
                             matches_dummy_announcement(
                                 u"tahoe-lafs-dummy-v1",
@@ -1294,7 +1423,7 @@ introducer.furl = pb://abcde@nowhere/fake
         self.useFixture(UseTestPlugins())
 
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(
                 storage_enabled=True,
@@ -1330,7 +1459,7 @@ introducer.furl = pb://abcde@nowhere/fake
         self.useFixture(UseTestPlugins())
 
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(
                 storage_enabled=True,
@@ -1346,7 +1475,7 @@ introducer.furl = pb://abcde@nowhere/fake
                 get_published_announcements,
                 MatchesListwise([
                     matches_storage_announcement(
-                        self.basedir,
+                        self.basedir.path,
                         options=[
                             matches_dummy_announcement(
                                 u"tahoe-lafs-dummy-v1",
@@ -1368,7 +1497,7 @@ introducer.furl = pb://abcde@nowhere/fake
         self.useFixture(UseTestPlugins())
 
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(
                 storage_enabled=True,
@@ -1395,7 +1524,7 @@ introducer.furl = pb://abcde@nowhere/fake
         available on the system.
         """
         config = client.config_from_string(
-            self.basedir,
+            self.basedir.path,
             "tub.port",
             self.get_config(
                 storage_enabled=True,

src/allmydata/test/test_introducer.py

@@ -52,8 +52,11 @@ from allmydata.util import pollmixin, idlib, fileutil, yamlutil
 from allmydata.util.iputil import (
     listenOnUnused,
 )
+from allmydata.scripts.common import (
+    write_introducer,
+)
 import allmydata.test.common_util as testutil
-from allmydata.test.common import (
+from .common import (
     SyncTestCase,
     AsyncTestCase,
     AsyncBrokenTestCase,
@@ -797,22 +800,28 @@ class Announcements(AsyncTestCase):
 
     @defer.inlineCallbacks
     def test_client_cache(self):
-        basedir = "introducer/ClientSeqnums/test_client_cache_1"
+        """
-        fileutil.make_dirs(basedir)
+        Announcements received by an introducer client are written to that
-        cache_filepath = FilePath(os.path.join(basedir, "private",
+        introducer client's cache file.
-                                               "introducer_default_cache.yaml"))
+        """
+        basedir = FilePath("introducer/ClientSeqnums/test_client_cache_1")
+        private = basedir.child("private")
+        private.makedirs()
+        write_introducer(basedir, "default", "nope")
+        cache_filepath = basedir.descendant([
+            "private",
+            "introducer_default_cache.yaml",
+        ])
 
         # if storage is enabled, the Client will publish its storage server
         # during startup (although the announcement will wait in a queue
         # until the introducer connection is established). To avoid getting
         # confused by this, disable storage.
-        with open(os.path.join(basedir, "tahoe.cfg"), "w") as f:
+        with basedir.child("tahoe.cfg").open("w") as f:
-            f.write("[client]\n")
+            f.write(b"[storage]\n")
-            f.write("introducer.furl = nope\n")
+            f.write(b"enabled = false\n")
-            f.write("[storage]\n")
-            f.write("enabled = false\n")
 
-        c = yield create_client(basedir)
+        c = yield create_client(basedir.path)
         ic = c.introducer_clients[0]
         private_key, public_key = ed25519.create_signing_keypair()
         public_key_str = remove_prefix(ed25519.string_from_verifying_key(public_key), b"pub-")
@@ -878,7 +887,7 @@ class Announcements(AsyncTestCase):
         self.failUnlessEqual(announcements[public_key_str2]["anonymous-storage-FURL"],
                              furl3)
 
-        c2 = yield create_client(basedir)
+        c2 = yield create_client(basedir.path)
         c2.introducer_clients[0]._load_announcements()
         yield flushEventualQueue()
         self.assertEqual(c2.storage_broker.get_all_serverids(),
@@ -888,27 +897,24 @@ class ClientSeqnums(AsyncBrokenTestCase):
 
     @defer.inlineCallbacks
     def test_client(self):
-        basedir = "introducer/ClientSeqnums/test_client"
+        basedir = FilePath("introducer/ClientSeqnums/test_client")
-        fileutil.make_dirs(basedir)
+        private = basedir.child("private")
+        private.makedirs()
+        write_introducer(basedir, "default", "nope")
         # if storage is enabled, the Client will publish its storage server
         # during startup (although the announcement will wait in a queue
         # until the introducer connection is established). To avoid getting
         # confused by this, disable storage.
-        f = open(os.path.join(basedir, "tahoe.cfg"), "w")
+        with basedir.child("tahoe.cfg").open("w") as f:
-        f.write("[client]\n")
+            f.write(b"[storage]\n")
-        f.write("introducer.furl = nope\n")
+            f.write(b"enabled = false\n")
-        f.write("[storage]\n")
-        f.write("enabled = false\n")
-        f.close()
 
-        c = yield create_client(basedir)
+        c = yield create_client(basedir.path)
         ic = c.introducer_clients[0]
         outbound = ic._outbound_announcements
         published = ic._published_announcements
         def read_seqnum():
-            f = open(os.path.join(basedir, "announcement-seqnum"))
+            seqnum = basedir.child("announcement-seqnum").getContent()
-            seqnum = f.read().strip()
-            f.close()
             return int(seqnum)
 
         ic.publish("sA", {"key": "value1"}, c._node_private_key)

src/allmydata/test/test_multi_introducers.py

@@ -24,9 +24,6 @@ class MultiIntroTests(unittest.TestCase):
         config = {'hide-ip':False, 'listen': 'tcp',
                   'port': None, 'location': None, 'hostname': 'example.net'}
         write_node_config(c, config)
-        fake_furl = "furl1"
-        c.write("[client]\n")
-        c.write("introducer.furl = %s\n" % fake_furl)
         c.write("[storage]\n")
         c.write("enabled = false\n")
         c.close()
@@ -36,8 +33,10 @@ class MultiIntroTests(unittest.TestCase):
 
     @defer.inlineCallbacks
     def test_introducer_count(self):
-        """ Ensure that the Client creates same number of introducer clients
+        """
-        as found in "basedir/private/introducers" config file. """
+        If there are two introducers configured in ``introducers.yaml`` then
+        ``Client`` creates two introducer clients.
+        """
         connections = {
             'introducers': {
                 u'intro1':{ 'furl': 'furl1' },
@@ -50,25 +49,13 @@ class MultiIntroTests(unittest.TestCase):
         ic_count = len(myclient.introducer_clients)
 
         # assertions
-        self.failUnlessEqual(ic_count, 3)
+        self.failUnlessEqual(ic_count, len(connections["introducers"]))
-
-    @defer.inlineCallbacks
-    def test_introducer_count_commented(self):
-        """ Ensure that the Client creates same number of introducer clients
-        as found in "basedir/private/introducers" config file when there is one
-        commented."""
-        self.yaml_path.setContent(INTRODUCERS_CFG_FURLS_COMMENTED)
-        # get a client and count of introducer_clients
-        myclient = yield create_client(self.basedir)
-        ic_count = len(myclient.introducer_clients)
-
-        # assertions
-        self.failUnlessEqual(ic_count, 2)
 
     @defer.inlineCallbacks
     def test_read_introducer_furl_from_tahoecfg(self):
-        """ Ensure that the Client reads the introducer.furl config item from
+        """
-        the tahoe.cfg file. """
+        The deprecated [client]introducer.furl item is still read and respected.
+        """
         # create a custom tahoe.cfg
         c = open(os.path.join(self.basedir, "tahoe.cfg"), "w")
         config = {'hide-ip':False, 'listen': 'tcp',
@@ -87,20 +74,42 @@ class MultiIntroTests(unittest.TestCase):
 
         # assertions
         self.failUnlessEqual(fake_furl, tahoe_cfg_furl)
+        self.assertEqual(
+            list(
+                warning["message"]
+                for warning
+                in self.flushWarnings()
+                if warning["category"] is DeprecationWarning
+            ),
+            ["tahoe.cfg [client]introducer.furl is deprecated; "
+             "use private/introducers.yaml instead."],
+        )
 
     @defer.inlineCallbacks
     def test_reject_default_in_yaml(self):
-        connections = {'introducers': {
+        """
-            u'default': { 'furl': 'furl1' },
+        If an introducer is configured in tahoe.cfg with the deprecated
-            }}
+        [client]introducer.furl then a "default" introducer in
+        introducers.yaml is rejected.
+        """
+        connections = {
+            'introducers': {
+                u'default': { 'furl': 'furl1' },
+            },
+        }
         self.yaml_path.setContent(yamlutil.safe_dump(connections))
+        FilePath(self.basedir).child("tahoe.cfg").setContent(
+            "[client]\n"
+            "introducer.furl = furl1\n"
+        )
+
         with self.assertRaises(ValueError) as ctx:
             yield create_client(self.basedir)
 
         self.assertEquals(
             str(ctx.exception),
-            "'default' introducer furl cannot be specified in introducers.yaml; please "
+            "'default' introducer furl cannot be specified in tahoe.cfg and introducers.yaml; "
-            "fix impossible configuration.",
+            "please fix impossible configuration.",
         )
 
 SIMPLE_YAML = """
@@ -126,8 +135,6 @@ class NoDefault(unittest.TestCase):
         config = {'hide-ip':False, 'listen': 'tcp',
                   'port': None, 'location': None, 'hostname': 'example.net'}
         write_node_config(c, config)
-        c.write("[client]\n")
-        c.write("# introducer.furl =\n") # omit default
         c.write("[storage]\n")
         c.write("enabled = false\n")
         c.close()

src/allmydata/test/test_node.py

@@ -684,8 +684,6 @@ class TestMissingPorts(unittest.TestCase):
 
 
 BASE_CONFIG = """
-[client]
-introducer.furl = empty
 [tor]
 enabled = false
 [i2p]

src/allmydata/test/test_storage_client.py

@@ -458,7 +458,7 @@ class StoragePluginWebPresence(AsyncTestCase):
             },
             storage_plugin=self.storage_plugin,
             basedir=self.basedir,
-            introducer_furl=ensure_text(SOME_FURL),
+            introducer_furl=SOME_FURL,
         ))
         self.node = yield self.node_fixture.create_node()
         self.webish = self.node.getServiceNamed(WebishServer.name)

src/allmydata/test/test_system.py

@@ -33,6 +33,9 @@ from allmydata.mutable.publish import MutableData
 
 from foolscap.api import DeadReferenceError, fireEventually, flushEventualQueue
 from twisted.python.failure import Failure
+from twisted.python.filepath import (
+    FilePath,
+)
 
 from .common import (
     TEST_RSA_KEY_SIZE,
@@ -47,6 +50,9 @@ from .web.common import (
 from allmydata.test.test_runner import RunBinTahoeMixin
 from . import common_util as testutil
 from .common_util import run_cli
+from ..scripts.common import (
+    write_introducer,
+)
 
 LARGE_DATA = """
 This is some data to publish to the remote grid.., which needs to be large
@@ -806,8 +812,6 @@ class SystemTestMixin(pollmixin.PollMixin, testutil.StallMixin):
 
         except1 = set(range(self.numclients)) - {1}
         feature_matrix = {
-            # client 1 uses private/introducers.yaml, not tahoe.cfg
-            ("client", "introducer.furl"): except1,
             ("client", "nickname"): except1,
 
             # client 1 has to auto-assign an address.
@@ -833,7 +837,6 @@ class SystemTestMixin(pollmixin.PollMixin, testutil.StallMixin):
         setnode = partial(setconf, config, which, "node")
         sethelper = partial(setconf, config, which, "helper")
 
-        setclient("introducer.furl", self.introducer_furl)
         setnode("nickname", u"client %d \N{BLACK SMILING FACE}" % (which,))
 
         if self.stats_gatherer_furl:
@@ -850,13 +853,11 @@ class SystemTestMixin(pollmixin.PollMixin, testutil.StallMixin):
 
         sethelper("enabled", "True")
 
-        if which == 1:
+        iyaml = ("introducers:\n"
-            # clients[1] uses private/introducers.yaml, not tahoe.cfg
+                 " petname2:\n"
-            iyaml = ("introducers:\n"
+                 "  furl: %s\n") % self.introducer_furl
-                     " petname2:\n"
+        iyaml_fn = os.path.join(basedir, "private", "introducers.yaml")
-                     "  furl: %s\n") % self.introducer_furl
+        fileutil.write(iyaml_fn, iyaml)
-            iyaml_fn = os.path.join(basedir, "private", "introducers.yaml")
-            fileutil.write(iyaml_fn, iyaml)
 
         return _render_config(config)
 
@@ -905,16 +906,21 @@ class SystemTestMixin(pollmixin.PollMixin, testutil.StallMixin):
         # usually this node is *not* parented to our self.sparent, so we can
         # shut it down separately from the rest, to exercise the
         # connection-lost code
-        basedir = self.getdir("client%d" % client_num)
+        basedir = FilePath(self.getdir("client%d" % client_num))
-        if not os.path.isdir(basedir):
+        basedir.makedirs()
-            fileutil.make_dirs(basedir)
         config = "[client]\n"
-        config += "introducer.furl = %s\n" % self.introducer_furl
         if helper_furl:
             config += "helper.furl = %s\n" % helper_furl
-        fileutil.write(os.path.join(basedir, 'tahoe.cfg'), config)
+        basedir.child("tahoe.cfg").setContent(config)
+        private = basedir.child("private")
+        private.makedirs()
+        write_introducer(
+            basedir,
+            "default",
+            self.introducer_furl,
+        )
 
-        c = yield client.create_client(basedir)
+        c = yield client.create_client(basedir.path)
         self.clients.append(c)
         c.set_default_mutable_keysize(TEST_RSA_KEY_SIZE)
         self.numclients += 1

tox.ini

@@ -95,12 +95,16 @@ setenv =
          #     .decode(getattr(sys.stdout, "encoding", "utf8"))
          # `TypeError: decode() argument 1 must be string, not None`
          PYTHONIOENCODING=utf_8
+
+	 # If no positional arguments are given, try to run the checks on the
+	 # entire codebase, including various pieces of supporting code.
+	 DEFAULT_FILES=src integration static misc setup.py
 commands =
-         flake8 src integration static misc setup.py
+         flake8 {posargs:{env:DEFAULT_FILES}}
-         python misc/coding_tools/check-umids.py src
+         python misc/coding_tools/check-umids.py {posargs:{env:DEFAULT_FILES}}
-         python misc/coding_tools/check-debugging.py
+         python misc/coding_tools/check-debugging.py {posargs:{env:DEFAULT_FILES}}
-         python misc/coding_tools/find-trailing-spaces.py -r src static misc setup.py
+         python misc/coding_tools/find-trailing-spaces.py -r {posargs:{env:DEFAULT_FILES}}
-         python misc/coding_tools/check-miscaptures.py
+         python misc/coding_tools/check-miscaptures.py {posargs:{env:DEFAULT_FILES}}
 
          # If towncrier.check fails, you forgot to add a towncrier news
          # fragment explaining the change in this branch.  Create one at