Re: Enhancements to git-protocoll

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 30, 2012, 02:38 UTC
Message-ID: <7vehnut1kt.fsf@alter.siamese.dyndns.org>
In-Reply-To: <CAJo=hJsgMz-=pdG=HB3KtTE7g6Gvu9mr56dg2+V3WUST+rpAQg@mail.gmail.com>

Shawn Pearce <spearce@spearce.org> writes:

> We sort of want this in Gerrit Code Review to pass reviewer names on
> the command line of git push, making it easier for users to upload a
> code review. The idea is similar to what happens with gcc accepting
> linker flags that are just passed onto the linker.

For reviewer names, authentication cookies and things of that nature where the extra pieces of information affect the outcome in a way that does not have to change how the underlying protocol exchange works, such an additional one-way channel from the pusher to pushee to carry auxiliary information would be sufficient. The server may decide to accept otherwise forbidden, or reject otherwise permitted, push based on the extra information given, for example, and that is an example of an enhancement that does not have to change how the underlying protocol exchange works.

The way to expose the extra information parsed by Git to the server side could be made into calling out to hooks, and at that point, gitolite would not even have to know about the pack protocol. Perhaps the interface to such a hook may be "hook can tell Git to abort the communication by exiting non-zero, after giving a message to its standard output".

It is a separate matter if it makes sense to add another channel that goes the other way on demand (i.e. taking the end-user response from the pusher and giving it to the pushee, and then allowing the pushee change its behaviour in a way more than just simply aborting the connection but performing a useful alternative operation)---I doubt it is.