[tahoe-lafs-trac-stream] [tahoe-lafs] #1536: nicely report any errors involving finding and using ifconfig

[tahoe-lafs]

#1536: nicely report any errors involving finding and using ifconfig
------------------------------+-------------------------------------------
     Reporter:  zooko         |      Owner:  zooko
         Type:  defect        |     Status:  assigned
     Priority:  major         |  Milestone:  undecided
    Component:  code-network  |    Version:  1.9.0a1
   Resolution:                |   Keywords:  error pyutil iputil archlinux
Launchpad Bug:                |
------------------------------+-------------------------------------------

Old description:

> A couple of users have recently [http://tahoe-lafs.org/pipermail/tahoe-
> dev/2011-September/006676.html reported] errors from [http://tahoe-
> lafs.org/trac/tahoe-
> lafs/browser/trunk/src/allmydata/util/iputil.py?annotate=blame&rev=4971#L177
> iputil] when it couldn't find their {{{ifconfig}}} executable, e.g.:
>
> {{{
> [Failure instance: Traceback: <type 'exceptions.OSError'>: [Errno 2] No
> such file or directory
> /usr/lib/python2.7/threading.py:525:__bootstrap
> /usr/lib/python2.7/threading.py:552:__bootstrap_inner
> /usr/lib/python2.7/threading.py:505:run
> - --- <exception caught here> ---
> /usr/lib/python2.7/site-packages/twisted/python/threadpool.py:207:_worker
> /usr/lib/python2.7/site-
> packages/twisted/python/context.py:118:callWithContext
> /usr/lib/python2.7/site-
> packages/twisted/python/context.py:81:callWithContext
> /home/kytv/tahoe/allmydata-
> tahoe-1.8.3/src/allmydata/util/iputil.py:222:_synchronously_find_addresses_via_config
> /home/kytv/tahoe/allmydata-
> tahoe-1.8.3/src/allmydata/util/iputil.py:236:_query
> /usr/lib/python2.7/subprocess.py:679:__init__
> /usr/lib/python2.7/subprocess.py:1228:_execute_child
> ]
> calling os.abort()
> }}}
> We should catch this exception and report a useful error message, saying
> what the {{{sys.platform}}} was and asking them to report about their
> {{{ifconfig}}}, like David-Sarah [http://tahoe-lafs.org/pipermail/tahoe-
> dev/2011-September/006677.html did] on the list:
> {{{
> which ifconfig
> ifconfig --help
> ifconfig
> }}}

New description:

 A couple of users have recently [http://tahoe-lafs.org/pipermail/tahoe-
 dev/2011-September/006676.html reported] errors from [http://tahoe-
 lafs.org/trac/tahoe-
 lafs/browser/trunk/src/allmydata/util/iputil.py?annotate=blame&rev=4971#L177
 iputil] when it couldn't find their {{{ifconfig}}} executable, e.g.:

 {{{
 [Failure instance: Traceback: <type 'exceptions.OSError'>: [Errno 2] No
 such file or directory
 /usr/lib/python2.7/threading.py:525:__bootstrap
 /usr/lib/python2.7/threading.py:552:__bootstrap_inner
 /usr/lib/python2.7/threading.py:505:run
 - --- <exception caught here> ---
 /usr/lib/python2.7/site-packages/twisted/python/threadpool.py:207:_worker
 /usr/lib/python2.7/site-
 packages/twisted/python/context.py:118:callWithContext
 /usr/lib/python2.7/site-
 packages/twisted/python/context.py:81:callWithContext
 /home/kytv/tahoe/allmydata-
 tahoe-1.8.3/src/allmydata/util/iputil.py:222:_synchronously_find_addresses_via_config
 /home/kytv/tahoe/allmydata-
 tahoe-1.8.3/src/allmydata/util/iputil.py:236:_query
 /usr/lib/python2.7/subprocess.py:679:__init__
 /usr/lib/python2.7/subprocess.py:1228:_execute_child
 ]
 calling os.abort()
 }}}
 We should catch this exception and report a useful error message, saying
 what the {{{sys.platform}}} was and asking them to report about their
 {{{ifconfig}}}, like David-Sarah [http://tahoe-lafs.org/pipermail/tahoe-
 dev/2011-September/006677.html did] on the list:
 {{{
 which ifconfig
 ifconfig --help
 ifconfig
 }}}

--

Comment (by mk.fg):

 I've just created [https://github.com/tahoe-lafs/tahoe-lafs/pull/14 pull
 request (#14) on github] with a simple patch to use $PATH to find
 ifconfig.
 A few questions that went through my mind during that process:

 * Is there any particular reason why it's used only on windows?
 * Why OS-native path resolution mechanics (which Popen() will use through
 os.execvp()) are overidden with twisted which() util?

 I considered adding optional iproute2 support, as suggested above (and
 indeed, net-tools are deprecated in many distros), but I think it's a
 wrong way to do it - iproute2 docs clearly state that it's output is a
 subject to change (and it's usually updated once per kernel release) and
 is not designed to be parseable, so maybe some specialized netlink module
 should be used on linux instead?

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1536#comment:5>
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