Re: [PATCH] http: match headers case-insensitively when redacting

From: Jeff King <peff@peff.net>
Date: Sep 22, 2021, 20:11 UTC
Message-ID: <YUuN+KguN0WetC49@coredump.intra.peff.net>
In-Reply-To: <afd7bd6b-52bf-7fd8-d13e-6dcd660c4100@gmail.com>

On Wed, Sep 22, 2021 at 09:32:41AM +0700, Bagas Sanjaya wrote:

Show 20 quoted lines

> > but this has a few issues:
> > 
> >    - it's not necessarily portable. The http2 apache module might not be
> >      available on all systems. Further, the http2 module isn't compatible
> >      with the prefork mpm, so we have to switch to something else. But we
> >      don't necessarily know what's available. It would be nice if we
> >      could have conditional config, but IfModule only tells us if a
> >      module is already loaded, not whether it is available at all.
> > 
> >      This might be a non-issue. The http tests are already optional, and
> >      modern-enough systems may just have both of these. But...
> > 
> >    - if we do this, then we'd no longer be testing HTTP/1.1 at all. I'm
> >      not sure how much that matters since it's all handled by curl under
> >      the hood, but I'd worry that some detail leaks through. We'd
> >      probably want two scripts running similar tests, one with HTTP/2 and
> >      one with HTTP/1.1.
> 
> Maybe for httpd config we can say that if mpm_prefork isn't loaded, load
> mpm_event and mod_http2.

That doesn't work. We can say "is mpm_prefork" loaded, and indeed we already do, in order to load mpm_prefork! That's because the module may or may not be built-in, and if not, we have to load it (or some mpm module). See 296f0b3ea9 (t/lib-httpd/apache.conf: configure an MPM module for apache 2.4, 2013-06-09).

But we have no way of knowing _which_ modules are available. It may just be that "event" or "worker" (both of which support mod_http2) are available close enough to everywhere that we can just guess.

> And for testing both HTTP/2 and HTTP/1.1 did you mean sharing the same test
> code (with adjustments for each protocol)?

Yes. I'd literally run the same battery of tests against both protocols (see my other response to Taylor with a sketched-out example). I'm still not sure it's entirely worth the effort, though. The underlying transport should be pretty transparent to Git, with the exception of things like debugging output.

-Peff