HTTP pushes

HTTP is currently listed as a read-only/unsupported method for doing pushes, is that due to inherent problems with HTTP or just because it hasn't been written yet?

I've built a working prototype of an HTTP push implementation using DAV. It locks the remote branch file during the push and PUTs to temp files to insure nobody else reads objects while they're being pushed. It does not validate remote objects - if they exist on the remote end as loose objects or in a pack, local copies won't be pushed. It supports sparse object directories, and verifies that the remote branch is an ancestor of the local branch before doing anything.

I'm curious to know whether it would be useful to proceed further, and to know what I haven't thought about yet...

For a successful technology, reality must take precedence over public
relations, for nature cannot be fooled.

Hi,

I think this is useful. There are restrictive firewalls out there, which only allow ports 80 and 443 to be connected to. Your work would fit in right there.

BTW, if the push would be relatively big, it would be nice to support pushing packs...

Ciao,
Dscho

I had an impression that DAV has its own notion of version control, so using git as a backend on the server side might be an interesting exercise.

Another solution for this would be to allow connect.c to use a HTTP connect passthru proxy. CVS does this with an ugly but easy to understand notation:

    ':pserver;proxy=firewall;proxyport=3128:user@host:/path/to/repo

There are versioning extensions to DAV, but they're not supported in all implementations - for example, Apache's mod_dav only supports the distributed authoring methods and that's what I've been testing with. Pushing should work fine to a version-aware DAV server, although the push should fail if the repository files are version-controlled (they don't have to be, and it wouldn't make sense for them to be anyway.)

For a successful technology, reality must take precedence over public
relations, for nature cannot be fooled.

please note that there are firewalls out there that don't let you use port 443 (and the connect command) as a free pass to do anything you want. They verify that you at least do a valid SSL handshake immediatly after or they figure you are trying to bypass them and shut you down.

David Lang

There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies.
 -- C.A.R. Hoare

Hi,

IIRC Subversion can operate over DAV, too.

Ciao,
Dscho

You obviously need a bit more than HTTP, and I don't personally know DAV. Also, I was writing things with all of the control on the receiving side, which isn't going to be the case here. If you've got a suitable environment for that sort of thing, I say go for it.

-Daniel
*This .sig left intentionally blank*

Not really, as long as you can GET and POST arbitrary files. Arguably, that's not how POST is typically used, though.

-hpa