[tahoe-lafs-trac-stream] [Tahoe-LAFS] #2862: introducers.yaml causes foolscap assertion

[Tahoe-LAFS]

#2862: introducers.yaml causes foolscap assertion
----------------------------+------------------------
 Reporter:  warner          |          Owner:
     Type:  defect          |         Status:  new
 Priority:  major           |      Milestone:  1.12.1
Component:  code-nodeadmin  |        Version:  1.12.0
 Keywords:                  |  Launchpad Bug:
----------------------------+------------------------
 User "lazygravy" on IRC reported a node-startup exception that happens
 when `private/introducers.yaml` is used. The problem appears to be that
 the FURL given to foolscap is a unicode string, and there is code inside
 foolscap which asserts that the connection hints it sees are normal
 strings (not unicode). The exception (as recorded in twistd.log) looks
 like:

 {{{
 Unhandled error in Deferred:
   Traceback (most recent call last):
     File "/usr/local/lib/python2.7/site-packages/foolscap/pb.py", line
 856, in connectTo
       rc.startConnecting(self)
     File "/usr/local/lib/python2.7/site-packages/foolscap/reconnector.py",
 line 78, in startConnecting
       self._connect()
     File "/usr/local/lib/python2.7/site-packages/foolscap/reconnector.py",
 line 110, in _connect
       d = self._tub.getReference(self._url)
     File "/usr/local/lib/python2.7/site-packages/foolscap/pb.py", line
 794, in getReference
       return defer.maybeDeferred(self._getReference, sturdyOrURL)
   --- <exception caught here> ---
     File "/usr/local/lib/python2.7/site-
 packages/twisted/internet/defer.py", line 150, in maybeDeferred
       result = f(*args, **kw)
     File "/usr/local/lib/python2.7/site-packages/foolscap/pb.py", line
 811, in _getReference
       d = self.getBrokerForTubRef(sturdy.getTubRef())
     File "/usr/local/lib/python2.7/site-
 packages/foolscap/referenceable.py", line 804, in getTubRef
       return TubRef(self.tubID, self.locationHints)
     File "/usr/local/lib/python2.7/site-
 packages/foolscap/referenceable.py", line 837, in __init__
       locationHints
   exceptions.AssertionError:
 [u'cz3uevcjrgwszq4ytvgisdw2nsdzgaxfan4nvh7uy5bxcbr7qv4q.b32.i2p']
 }}}

 I think the code that loads the YAML file needs to do an
 `.encode("ascii")` on any of the FURLs it extracts, before passing them to
 foolscap.

 In addition, docs/configuration.rst had an invalid example for the
 `private/introducers.yaml` section (around line 920). It said:

 {{{
 introducers:
   petname2: furl = FURL2
 }}}

 but that will result in a data structure like `introducers = {"petname2":
 "furl = FURL2"}`, which causes an exception at node startup time like
 this:

 {{{
   File "/usr/local/lib/python2.7/site-packages/allmydata/client.py", line
 189, in __init__
     self.init_introducer_clients()
   File "/usr/local/lib/python2.7/site-packages/allmydata/client.py", line
 268, in init_introducer_clients
     ic = IntroducerClient(self.tub, introducer['furl'],
 exceptions.TypeError: string indices must be integers
 }}}

 Instead, the docs should recommend:

 {{{
 introducers:
   petname2:
     furl: FURL2
 }}}

--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2862>
Tahoe-LAFS <https://Tahoe-LAFS.org>
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