[Mailman-Users] Recent trouble with DMARC Munging

[Lindsay Haisley]

On Tue, 2017-01-17 at 07:40 -0500, Brian Carpenter wrote:
> > 
> > Lindsay Haisley writes:
> > 
> >  > I don't believe that the python DNS resolver module is a stock part of
> >  > the python distribution.
> > 
> > It is not, as of 3.6.

Nor was it part of 2.6 or 2.7.

Scott's original issue apparently was (exactly as I suggested in an
earlier post in this thread) that python, on his problem system, was
upgraded from v2.6 to v2.7, sans dnspython, which is neither part of
the python standard library nor part of the accessory packages
installed by cPanel or by the distribution's suggested dependencies
map.

> > ------------------------------------------------------
> cPanel has confirmed the bug and they are currently working on providing a
> fix that will be pushed out in an update. Meanwhile they did provide me a
> workaround that fixes the issue. Here is what they said related to the
> reported bug:

So inquiring minds want to know. Why is this a cPanel bug? Mark's
solution suggesting the use of pip to remedy the problem seems to
satisfy the KISS principle, Ockam's Razor, and whatever other system
admin guidelines teach the virtue of simplicity and the power of a
little knowledge of how things work "under the hood".

As I recall, as well, there were, at one point, not one but at least
two DNS resolution modules available for python - dnspython, PyDNS, and
now perhaps python-dns, which are similar but differ with regard to
such trivia as the case of the module name in import directives, but
which will surely cause exceptions if the calling conventions aren't
strictly followed.

This all underscores the problems of relying on other people's
organization, and the resulting dependency on other people's confusion
that comes from blind reliance on über-packages (especially proprietary
über-packages) such as cPanel which obfuscate and complicate solutions
to simple problems. The following quoted "explanation", presumably from
cPanel, is a perfect example. Exactly _which_ python DNS module are we
talking about here? It's clear as mud!

Hrrumph!!

> 
> ######################################
> Indeed, I've replicated this concern on our test servers and I see
> that the
> location has changed in the latest RPM from python 2.6 to python 2.7.
> 
> As Cent7 provides python-dns, there is not a need to provide this
> package
> for python 2.7 as the system provided python-dns library can be
> used. 
> 
> We provide cpanel-dnspython on Cent 6 systems as python-dns  is not
> available. It appears that in the recent package, the installation
> has been
> moved to /usr/lib64/python2.7 rather then the previous location of
> /usr/lib/python2.6  or the expected location of
> /usr/lib64/python2.6. 
> 
> I've downgraded the installed cpanel-dnspython on a test server which
> then
> allowed for the module to be located without issues
> ######################################
> 
> Hats off to Mark Sapiro and to his pinpoint super human laser
> accuracy to
> identify the source of these problems that come up from time to
> time. 

-- 
Lindsay Haisley       | "The first casualty when
FMP Computer Services |         war comes is truth."
512-259-1190          |            
http://www.fmp.com    |     -- Hiram W Johnson