Re: Git-aware HTTP transport

From: Shawn O. Pearce <spearce@spearce.org>
Date: Aug 26, 2008, 14:58 UTC
Message-ID: <20080826145857.GF26523@spearce.org>
In-Reply-To: <48B36BCA.8060103@zytor.com>

"H. Peter Anvin" <hpa@zytor.com> wrote:

Show 6 quoted lines

>> Detecting Smart Servers
>> -----------------------
>>
>> HTTP clients can detect a smart Git-aware server by HEADing
>> $repo/backend.git-http and looking for a 302 redirect to the
>> repository's smart service URL:

...

Show 9 quoted lines

>> All subsequent communcation for this transaction is done through
>> the smart service URL ($ssurl), not the original URL.
>
> I actually suggest embedding the forwarding URL into an ordinary  
> payload.  Instead of a HEAD request here, then do a GET (or, even  
> better, POST) and get the redirected URL in return.
>
> Why?  Because it's common enough to redirect entire trees, and use of  
> HTTP-layer redirections here is an unnecessary layering violation.

Hmm. I'm actually thinking the exact opposite here. My rationale for putting the response as a standard HTTP 302/303 style redirect is to permit hardware load balancers or Apache mod_rewrite rules to implement simple load balancing with a HTTP redirect.

If we embed the redirect URL into the payload then configuring that will become a lot more complex. At the minimum you may have to make up a dummy file for each server (holding the response payload) then then let mod_rewrite rewrite the request internally to make Apache serve that file. Ugly.

> If you insist on using a HTTP status code, I would claim that 303 is a  
> better status code.

Ok.

-- 
Shawn.