Date: Fri, 29 Aug 2014 14:21:52 +0000
Message-ID: <20140829142152.Horde.Rvytg4DkUxNQ4e9EZ5Ls1w2@mail.das-netzwerkteam.de>
From: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
To: submit@bugs.x2go.org
Subject: GEVENT_RESOLVER=ares should be preferred
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Package: python-x2go
Severity: important

Since python-gevent 1.0 gevent fails to detect DNS changes (e.g. when=20=20
connecting to a VPN server).

 From http://gevent.org/whatsnew_1_0.html :

"""
New dns resolver

Two new DNS resolvers: threadpool-based one (enabled by default) and=20=20
c-ares based one. That threadpool-based resolver was added mostly for=20=20
Windows and Mac OS X platforms where c-ares might behave differently=20=20
w.r.t system configuration. On Linux, however, the c-ares based=20=20
resolver is probably a better choice. To enable c-ares resolver set=20=20
GEVENT_RESOLVER=3Dares environment variable.

This fixes some major issues with DNS on 0.13.x, namely:

     Issue #2: DNS resolver no longer breaks after fork(). You still=20=20
need to call gevent.fork() (os.fork is monkey patched with it if=20=20
monkey.patch_all() was called).
     DNS resolver no longer ignores /etc/resolv.conf and /etc/hosts.

The following functions were added to socket module:

     gethostbyname_ex
     getnameinfo
     gethostbyaddr
     getfqdn

It is possible to implement your own DNS resolver and make gevent use=20=20
it. The GEVENT_RESOLVER variable can point to alternative=20=20
implementation using the format: package.module.class. The default is=20=20
gevent.resolver_thread.Resolver. The alternative =E2=80=9Cares=E2=80=9D res=
olver is an=20=20
alias for gevent.resolver_ares.Resolver.
"""

Thus: we need to enforce setting of env variable GEVENT_RESOLVER=3Dares=20=
=20
in Python X2Go.

Mike
--=20

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