Re: Why does resolv.conf keep changing?

[Roberto C. Sánchez <roberto@debian.org>]

On Mon, Oct 23, 2017 at 11:25:05AM +0200, tomas@tuxteam.de wrote:
> On Mon, Oct 23, 2017 at 09:17:11AM +0100, Joe wrote:
> > On Sun, 22 Oct 2017 22:12:03 -0400
> > Roberto C. Sánchez <roberto@debian.org> wrote:
> 
> [...]
> 
> > > I did find a page on the Debian wiki [0] which recommends setting the
> > > immutable attribute on /etc/resolv.conf.  However, that feels like an
> > > ugly hack.
> > > 
> > 
> > It most certainly is, and shouldn't be necessary in your case.
> 
> I've used that approach sometimes and regularly recommend it.
> 
> That said, my main intention is to *debug* the problem, i.e. to
> provoke an error message in some log file or whatever, to learn which
> process is (undesirably?) mutating some file. Most of the time this
> leads to learning some config option to not do that mutation in the
> first place (or to some understanding on why that mutation is a Good
> Thing after all and to a better way of solving my real, underlying
> problem).
> 
> Only in exceptional cases I had to "leave in" the immutable attribute
> as a permanent "solution".
> 

So, I edited resolv.conf to my preference and then made it immutable
with `chattr +i /etc/resolv.conf`.  Several hours later the name server
was changed back to the ISP router's address.  That is very odd.  Yet
even more odd is that this time the domain and search options were left
untouched.  Previously, the domain and search would get wiped (because
the ISP router doesn't push those options).

The plot thickens.

Regards,

-Roberto
-- 
Roberto C. Sánchez