Re: [PATCH] http: add custom hostname to IP address resolves

From: Christian Couder <christian.couder@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: git <git@vger.kernel.org>,
	Christian Couder <chriscool@tuxfamily.org>,
	Derrick Stolee <derrickstolee@github.com>,
	Jacob Vosmaer <jacob@gitlab.com>
Subject: Re: [PATCH] http: add custom hostname to IP address resolves
Date: Thu, 5 May 2022 12:48:50 +0200	[thread overview]
Message-ID: <CAP8UFD0V6scSD8LuUiRQ0BWmG2mFATVFNQ2DgwaWFp6bigBkZw@mail.gmail.com> (raw)
In-Reply-To: <xmqqzgjxnz73.fsf@gitster.g>

On Wed, May 4, 2022 at 4:34 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Christian Couder <christian.couder@gmail.com> writes:

> > I am Ok with just "http.resolve". I think using "curlopt" is perhaps
> > going into too many details about the implementation of the feature,
> > which could theoretically change if we ever decided to use something
> > other than curl.
>
> You may want to step back a bit and rethink.
>
> Even if we decide to rewrite that part of the system not to depend
> on cURL, end-user facing documented interface, i.e. how the mappings
> are given to the system, will stay with us, and it is clear that it
> was modeled after CURLOPT_RESOLVE---well, it was stolen from them
> verbatim ;-).
>
> So we may wean ourselves off of cURL, but CURLOPT_RESOLVE will stay
> with us for this particular feature.

Yeah, the CURLOPT_RESOLVE format will stay with us, so Ok, I will
rename it "http.curloptResolve" in the next iteration then.

> >> I am wondering if we want to mention the expected use case here
> >> as well, something like
> >>
> >>     This is designed to be used primarily from the command line
> >>     configuration variable override, e.g.
> >>
> >>         $ git -c http.resolve=example.com:443:127.0.0.1 \
> >>             clone https://example.com/user/project.git
> >>
> >> perhaps?  Not a suggestion, but soliciting thoughts.
> >
> > I am also interested in others' thoughts about this. If no one thinks
> > that a config option could be useful, I am Ok with making it a
> > "--resolve" command line option that can be passed to any Git command
> > similar to "-c <name>=<value>":
> >
> > git --resolve=... <command> [<args>]
>
> Absolutely not.
>
> "git [push|fetch|clone|ls-remote] --dns-pre-resolve=..." that is
> *NOT* git wide, but is only for transport commands might be a
> possibility, but even then, you'd need to invent a way to do the
> same for non cURL transports (we want to be able to pin the IP when
> going over SSH to a certain host, for the same reason) if we promote
> it to an officially supported command line option.

Ok with renaming and implementing it only in transport commands. I
don't want, and I don't think it should be necessary, to invent a way
to do the same for non cURL transports though. I think it should be Ok
with the doc saying that the option has only been implemented for
HTTP(S) yet and will have no effect when other transports are used.

If there is a simple way to do the same thing for ssh, then I might
take a look at it later. For "file" or bundle transports, I don't
think it makes sense, and the "git" transport is not used much in big
hosting services where this feature is likely to be used.

> Unless we do that, it is probably better to leave it as an obscure
> configuration meant to help server operators.  At least, with the
> name of the configuration variable prefixed with http.*, we have a
> valid excuse when somebody complains "the feature does not do
> anything for git:// transport".

I am happy with leaving it as an obscure configuration meant to help
server operators. So I will just rename it "http.curloptResolve" in
the next iteration.

Thanks!