The stdlib 'subprocess' module in python-2.7.4 through 2.7.7 suffers
from http://bugs.python.org/issue18851 which causes unrelated file
descriptors to be closed when `subprocess.call()` fails the `exec()`,
such as when the executable being invoked does not actually exist. There
appears to be some randomness involved. This was fixed in python-2.7.8.
Tahoe's iputil.py uses subprocess.call on many different "ifconfig"-type
executables, most of which don't exist on any given platform (added in
git commit 8e31d66cd0). This results in a lot of file-descriptor
closing, which (at least during unit tests) tends to clobber important
things like Tub TCP sockets. This seems to be the root cause behind
ticket:2121, in which normal code tries to close already-closed sockets,
crashing the unit tests. Since different platforms have different
ifconfigs, some platforms will experience more failed execs than others,
so this bug could easily behave differently on linux vs freebsd, as well
as working normally on python-2.7.8 or 2.7.4.
This patch inserts a guard to make sure that os.path.isfile() is true
before allowing Popen.call() to try executing the target. This ought to
be enough to avoid the bug. It changes both iputil.py and
allmydata.__init__ (which uses Popen for calling "lsb_release"), which
are all the places where 'subprocess' is used outside of unit tests.
Other potential fixes: use the 'subprocess32' module from PyPI (which is
a bug-free backport of the Python3 stdlib subprocess module, but would
introduce a new dependency), or require python >= 2.7.8 (but this would
rule out development/deployment on the current OS-X 10.9 release, which
ships with 2.7.5, as well as other distributions like Ubuntu 14.04 LTS).
I believe this closes ticket:2121, and given the apparent relationship
between 2121 and 2023, I think it also closes ticket:2023 (although
since 2023 doesn't have copies of the failing log files, it's hard to
tell). I'm hoping that this will tide us over until 1.11 is released, at
which point we can execute on the plan to remove iputil.py entirely by
changing the way that nodes learn their externally-facing IP address.
I want mode="w" (i.e. text, with newline conversion) for code that
writes newline-terminated strings (which should also be human readable)
to files. I like to use things like "cat .tahoe/permutation-seed"
without seeing the seed jammed together with the next command prompt.
This also simplifies how case-insensitivity is handled, and fixes a corner case
where the wrong exception was raised when the size ends in "BB".
fixes#1812
Signed-off-by: David-Sarah Hopwood <davidsarah@mint>
Unlike set.union(), which returns a new set, DictOfSets.union() modified
the DictOfSets in-place. The name collision bit me when I changed some
code from using DictOfSets to a normal set, and expected that
set.union() would modify the set in-place. Since there was only one user
of DictOfSets.union, I figured it was safer to just get rid of it.
Previously, test_runner sometimes fails because the _node_has_started()
poller fires after the portnum file has been opened, but before it has
actually been filled, allowing the test process to observe an empty file,
which flunks the test.
This adds a new fileutil.write_atomically() function (using the usual
write-to-.tmp-then-rename approach), and uses it for both node.url and
client.port . These files are written a bit before the node is really up and
running, but they're late enough for test_runner's purposes, which is to know
when it's safe to read client.port and use 'tahoe restart' (and therefore
SIGINT) to restart the node.
The current node/client code doesn't offer any better "are you really done
with startup" indicator.. the ideal approach would be to either watch the
logfile, or connect to its flogport, but both are a hassle. Changing the node
to write out a new "all done" file would be intrusive for regular
operations.
This significantly cleans up the IntroducerServer web-status renderers.
Instead of poking around in the introducer's internals, now the web-status
renderers get clean AnnouncementDescriptor and SubscriberDescriptor
objects. They are still somewhat foolscap-centric, but will provide a clean
abstraction boundary for future improvements.
The specific #1721 bug was that old (V1) subscribers were handled by
wrapping their RemoteReference in a special WrapV1SubscriberInV2Interface
object, but the web-status display was trying to peek inside the object to
learn what host+port it was associated with, and the wrapper did not proxy
those extra attributes.
A test was added to test_introducer to make sure the introweb page renders
properly and at least contains the nicknames of both the V1 and V2 clients.
This replaces the setup.cfg aliases that run "darcsver" before each major
command with the new "update_version". update_version is defined in setup.py,
and tries to get a version string from either darcs or git (or leaves the
existing _version.py alone if neither VC metadata is available).
Also clean up a tiny typo in verlib.py that messed up syntax hilighting.
No behavioral changes, just updating variable/method names and log messages.
The effects outside these three files should be minimal: some exception
messages changed (to say "server" instead of "peer"), and some internal class
names were changed. A few things still use "peer" to minimize external
changes, like UploadResults.timings["peer_selection"] and
happinessutil.merge_peers, which can be changed later.
The Range header causes n.read() to be called with an offset= of type 'long',
which eventually got used in a Spans/DataSpans object's __len__ method.
Apparently python doesn't permit __len__() to return longs, only ints.
Rewrote Spans/DataSpans to use s.len() instead of len(s) aka s.__len__() .
Added a test in test_download. Note that test_web didn't catch this because
it uses mock FileNodes for speed: it's probably time to rewrite that.
There is still an unresolved error-recovery problem in #1154, so I'm not
closing the ticket quite yet.
