From: Carlos O'Donell <carlos@redhat.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH 0/2] Fix nss/tst-nss-files-hosts-long on single-stack hosts (bug 24816)
Date: Wed, 14 Sep 2022 18:26:10 -0400 [thread overview]
Message-ID: <YyJVAs3wvG5fma96@fedora> (raw)
In-Reply-To: <877d26e0wo.fsf@oldenburg.str.redhat.com>
On Wed, Sep 14, 2022 at 11:54:47AM +0200, Florian Weimer wrote:
> * Carlos O'Donell:
>
> > On Tue, Sep 13, 2022 at 04:35:39PM +0200, Florian Weimer via Libc-alpha wrote:
> >> Our Fedora builders started running the container tests (after the
> >> switch to systemd-nspawn), and we encountered this test failure as well.
> >> Fix this by disabling address configuration in the getent tool.
> >
> > Two things I'd like to discuss.
> >
> > (1) Change the getent default and drop AI_ADDRCONFIG.
> >
> > I'm hesitant to add a new option to getent as a solution to a testing
> > problem. The documented description for getent ahosts talks only
> > about enumerating the host entries or calling getaddrinfo with
> > AF_UNSPEC. Could we just change the default and ignore the host
> > configuration? This is less conservative but logically it seems to me
> > that we could just drop AI_ADDRCONFIG, and add a --addrconfig option to
> > get back the old behaviour. What could we possibly break?
>
> I'm not sure why we would make such a backwards-incompatible change just
> to fix a test. It sounds even more preposterous than adding the new
> option.
I fully agree that the most backwards compatible change is to add
an option that allows getent to operate without AI_ADDRCONFIG.
What I want to explore here is: Why use AI_ADDRCONFIG at all with
getent?
If our collective answer is: Because that's just the way we've always
done it and changing it would be a backwards incompatible change, then
I'm fine with that. I just wanted to explore that a bit.
I can see arguments both ways. I was looking for your opinion here.
My read of your opinion is that we should make the minimum backwards
compatible change.
> There have been support cases where the --no-addrconfig option would
> have been useful. Today, getent isn't a great tool for diagnosing DNS
> issues, and I think this option improves the situation slightly.
That's a good point in favour of the new option.
> > (2) Fix the test.
> >
> > Alternatively the test should be checking to see if it is in a dual
> > stack environment or single stack environment and only call getent for
> > the specific case when such interfaces are enabled.
> >
> > Can we resolve this entirely in tst-nss-files-hosts-long?
>
> I think it's futile to try to replicate the AI_ADDRCONFIG behavior in
> the test.
I did an audit and it looks like getent, and this specific test are
the only ones that we'd need cood like this for, and so there isn't
a win-win here with other tests.
Cheers,
Carlos.
next prev parent reply other threads:[~2022-09-14 22:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-13 14:35 Florian Weimer
2022-09-13 14:35 ` [PATCH 1/2] nss: Implement --no-addrconfig option for getent Florian Weimer
2022-09-14 22:34 ` Carlos O'Donell
2022-09-15 12:11 ` Florian Weimer
2022-09-13 14:35 ` [PATCH 2/2] nss: Fix tst-nss-files-hosts-long on single-stack hosts (bug 24816) Florian Weimer
2022-09-14 22:35 ` Carlos O'Donell
2022-09-14 9:42 ` [PATCH 0/2] Fix nss/tst-nss-files-hosts-long " Carlos O'Donell
2022-09-14 9:54 ` Florian Weimer
2022-09-14 22:26 ` Carlos O'Donell [this message]
2022-09-15 12:37 ` Florian Weimer
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