Re: [RFC 0/7] transitioning to protocol v2

From: Jeff King <peff@peff.net>
Date: Aug 30, 2017, 03:06 UTC
Message-ID: <20170830030612.qjss3ygouardxi6k@sigill.intra.peff.net>
In-Reply-To: <2ff0ead4-e13a-220e-f858-36ab206c1485@jeffhostetler.com>

On Tue, Aug 29, 2017 at 04:08:25PM -0400, Jeff Hostetler wrote:

> I just wanted to jump in here and say I've done some initial
> testing of this against VSTS and so far it seems fine.  And yes,
> we have a custom git server.

Great, thank you for checking.

> VSTS doesn't support the "git://" protocol, so the double-null trick
> isn't an issue for us.  But "https://" worked just fine.  I'm still
> asking around internally whether we support passing SSH environment
> variables.

The key thing for ssh is not whether you support passing environment variables. It's whether you quietly ignore unknown variables rather than cutting off the connection.

To support the v2 protocol you'd need to pass the new variables, but you'd also need to modify your server to actually do something useful with them anyway. At this point we're mostly concerned with whether we can safely pass the variables to current implementations unconditionally and get a reasonable outcome.

To be honest, I'm not all that worried about VSTS either way. It's a centralized service which will likely get v2 extensions implemented in a timely manner (once they exist). I'm much more concerned about shrink-wrap implementations deployed in the wild, which may hang around without being upgraded for years. If v2-aware clients send requests that cause those old implementations to choke, users won't be happy.

-Peff