Make which pluggable transports are distributed easily configurable.

 * REMOVE bridgedb.strings.CURRENT_TRANSPORTS.

 * ADD b.strings.SUPPORTED_TRANSPORTS, which can be get/set with
   b.strings._getSupportedTransports() and
   _setSupportedTransports(). There is also a new SUPPORTED_TRANSPORTS
   option in bridgedb.conf; the setting at
   bridgedb.strings.SUPPORTED_TRANSPORTS is now automatically configured
   via the bridgedb.conf file.

 * ADD b.strings.DEFAULT_TRANSPORT, which can be get/set with
   b.strings._getDefaultTransport() and _setDefaultTransport(). There is
   also a new DEFAULT_TRANSPORT option in bridgedb.conf; the setting at
   bridgedb.strings.DEFAULT_TRANSPORT is now automatically configured
   via the bridgedb.conf file.

 * CHANGE options.html template to automatically populate the list of
   available transports. The DEFAULT_TRANSPORT is automatically the
   selected default.

 * FIXES #12504: https://bugs.torproject.org/12504

bridgedb.conf

@@ -20,6 +20,9 @@
 #
 # CHANGELOG:
 # ~~~~~~~~~~
+# Changed in version 0.0.15 - 2015-03-26
+#   * ADD new SUPPORTED_TRANSPORTS and DEFAULT_TRANSPORT settings.
+#
 # Changes in version 0.0.14 - 2015-02-22
 #   * ADD new OpenPGP-related options:
 #        - EMAIL_GPG_HOMEDIR
@@ -237,6 +240,21 @@ TASKS = {
     'GET_TOR_EXIT_LIST': 3 * 60 * 60,
 }
 
+# SUPPORTED_TRANSPORTS is a dictionary mapping Pluggable Transport methodnames
+# to booleans. If ``True``, the PT is distributed; if ``False``, it isn't.
+SUPPORTED_TRANSPORTS = {
+    'obfs2': True,
+    'obfs3': True,
+    'obfs4': True,
+    'scramblesuit': True,
+    'fte': True,
+}
+
+# DEFAULT_TRANSPORT is a string. It should be the PT methodname of the
+# transport which is selected by default (e.g. in the webserver dropdown
+# menu).
+DEFAULT_TRANSPORT = 'obfs4'
+
 #-------------------------------
 # HTTP(S) Distribution Options  \
 #------------------------------------------------------------------------------

lib/bridgedb/configure.py

@@ -14,6 +14,9 @@
 import logging
 import os
 
+# Used to set the SUPPORTED_TRANSPORTS:
+from bridgedb import strings
+
 
 def loadConfig(configFile=None, configCls=None):
     """Load configuration settings on top of the current settings.
@@ -116,6 +119,17 @@ def loadConfig(configFile=None, configCls=None):
         setting = getattr(config, attr, []) # Default to empty lists
         setattr(config, attr, setting)
 
+    for attr in ["SUPPORTED_TRANSPORTS"]:
+        setting = getattr(config, attr, {}) # Default to emtpy dicts
+        setattr(config, attr, setting)
+
+    # Set the SUPPORTED_TRANSPORTS to populate the webserver and email options:
+    strings._setSupportedTransports(getattr(config, "SUPPORTED_TRANSPORTS", {}))
+    strings._setDefaultTransport(getattr(config, "DEFAULT_TRANSPORT", ""))
+    logging.info("Currently supported transports: %s" %
+                 " ".join(strings._getSupportedTransports()))
+    logging.info("Default transport: %s" % strings._getDefaultTransport())
+
     for domain in config.EMAIL_DOMAINS:
         config.EMAIL_DOMAIN_MAP[domain] = domain
 

lib/bridgedb/email/templates.py

@@ -53,7 +53,7 @@ def addCommands(template):
     # And include the currently supported transports:
     commands += template.gettext(strings.EMAIL_MISC_TEXT.get(5))
     commands += "\n"
-    for pt in strings.CURRENT_TRANSPORTS:
+    for pt in strings._getSupportedTransports():
         commands += '  ' + pt + "\n"
 
     return commands

lib/bridgedb/strings.py

@@ -1,4 +1,4 @@
-# -*- coding: utf-8 -*-
+# -*- coding: utf-8 ; test-case-name: bridgedb.test.test_strings ; -*-
 #
 # This file is part of BridgeDB, a Tor bridge distribution system.
 #
@@ -10,6 +10,12 @@
 
 from __future__ import unicode_literals
 
+# This won't work on Python2.6, however
+#     1) We don't use Python2.6, and
+#     2) We don't care about supporting Python2.6, because Python 2.6 (and,
+#        honestly, all of Python2) should die.
+from collections import OrderedDict
+
 
 def _(text):
     """This is necessary because strings are translated when they're imported.
@@ -166,21 +172,85 @@ def _(text):
 #           All of the following containers are untranslated!
 #-----------------------------------------------------------------------------
 
-#: A list of all currently available pluggable transports. By "currently
-#: available" we mean:
+#: SUPPORTED TRANSPORTS is dictionary mapping all Pluggable Transports
+#: methodname to whether or not we actively distribute them. The ones which we
+#: distribute SHOULD have the following properties:
 #:
 #:   1. The PT is in a widely accepted, usable state for most Tor users.
 #:   2. The PT is currently publicly deployed *en masse*".
 #:   3. The PT is included within the transports which Tor Browser offers in
 #:      the stable releases.
 #:
-CURRENT_TRANSPORTS = [
-    "obfs2",
-    "obfs3",
-    "obfs4",
-    "scramblesuit",
-    "fte",
-]
+#: These will be sorted by methodname in alphabetical order.
+#:
+#: ***Don't change this setting here; change it in :file:`bridgedb.conf`.***
+SUPPORTED_TRANSPORTS = {}
+
+#: DEFAULT_TRANSPORT is a string. It should be the PT methodname of the
+#: transport which is selected by default (e.g. in the webserver dropdown
+#: menu).
+#:
+#: ***Don't change this setting here; change it in :file:`bridgedb.conf`.***
+DEFAULT_TRANSPORT = ''
+
+def _getSupportedTransports():
+    """Get the list of currently supported transports.
+
+    :rtype: list
+    :returns: A list of strings, one for each supported Pluggable Transport
+        methodname, sorted in alphabetical order.
+    """
+    supported = [name.lower() for name,w00t in SUPPORTED_TRANSPORTS.items() if w00t]
+    supported.sort()
+    return supported
+
+def _setDefaultTransport(transport):
+    global DEFAULT_TRANSPORT
+    DEFAULT_TRANSPORT = transport
+
+def _getDefaultTransport():
+    return DEFAULT_TRANSPORT
+
+def _setSupportedTransports(transports):
+    """Set the list of currently supported transports.
+
+    .. note: You shouldn't need to touch this. This is used by the config file
+        parser. You should change the SUPPORTED_TRANSPORTS dictionary in
+        :file:`bridgedb.conf`.
+
+    :param dict transports: A mapping of Pluggable Transport methodnames
+        (strings) to booleans.  If the boolean is ``True``, then the Pluggable
+        Transport is one which we will (more easily) distribute to clients.
+        If ``False``, then we (sort of) don't distribute it.
+    """
+    global SUPPORTED_TRANSPORTS
+    SUPPORTED_TRANSPORTS = transports
+
+def _getSupportedAndDefaultTransports():
+    """Get a dictionary of currently supported transports, along with a boolean
+    marking which transport is the default.
+
+    It is returned as a :class:`collections.OrderedDict`, because if it is a
+    regular dict, then the dropdown menu would populated in random order each
+    time the page is rendered.  It is sorted in alphabetical order.
+
+    :rtype: :class:`collections.OrderedDict`
+    :returns: An :class:`~collections.OrderedDict` of the Pluggable Transport
+        methodnames from :data:`SUPPORTED_TRANSPORTS` whose value in
+        ``SUPPORTED_TRANSPORTS`` is ``True``.  If :data:`DEFAULT_TRANSPORT` is
+        set, then the PT methodname in the ``DEFAULT_TRANSPORT`` setting is
+        added to the :class:`~collections.OrderedDict`, with the value
+        ``True``. Every other transport in the returned ``OrderedDict`` has
+        its value set to ``False``, so that only the one which should be the
+        default PT is ``True``.
+    """
+    supported = _getSupportedTransports()
+    transports = OrderedDict(zip(supported, [False for _ in range(len(supported))]))
+
+    if DEFAULT_TRANSPORT:
+        transports[DEFAULT_TRANSPORT] = True
+
+    return transports
 
 EMAIL_SPRINTF = {
     # Goes into the "%s types of Pluggable Transports %s" part of ``WELCOME[0]``

lib/bridgedb/templates/options.html

@@ -87,11 +87,14 @@ <h3 class="panel-title">${_("""Advanced Options""")}</h3>
                               accesskey="t">
                         ${_("""No""")}
 <option label="none"  value="0"        >${_("none")}</option>
-<option label="obfs2" value="obfs2"              >obfs2</option>
-<option label="obfs3" value="obfs3"   selected   >obfs3</option>
-<option label="obfs4" value="obfs4"              >obfs4</option>
-<option label="scramblesuit" value="scramblesuit">scramblesuit</option>
-<option label="fte"   value="fte"                >fteproxy</option>
+% for methodname, default in strings._getSupportedAndDefaultTransports().items():
+    <option label=${methodname}
+            value=${methodname}
+    % if default:
+            selected
+    % endif
+            > ${methodname} </option>
+% endfor
                       </select>
                     </div>
                   </div>