Re: bundles discovery and clones

matthew sporleder
2024-06-11T11:15:00Z

On Tue, Jun 11, 2024 at 3:21 AM Jeff King <peff@peff.net> wrote:
>
> On Mon, Jun 10, 2024 at 02:25:19PM -0400, matthew sporleder wrote:
>
> > I have recently been playing with git clone --bundle-uri and loving it
> > because I can clone with almost-*zero* resources being used on the
> > server!
> >
> > I am a little confused by https://git-scm.com/docs/bundle-uri
> > mentioning "discovery" and things. Is this something being added to
> > the git cli, a special feature for other clients, or is it still too
> > early-days to talk about much?
> >
> > I would love to produce bundles of common use cases and have them
> > auto-discovered by git clone *without* the --bundle-uri parameter, and
> > then let our CDN do the heavy lifting of satisfying things like:
> > git clone
> > git clone --depth=0
> > git clone --single-branch --branch main
> >
> > I'm not sure I hold out as much hope for pre-bundling pulls/updates
> > but any movement towards offloading our big-ish repos to CDNs is a win
> > for us.
>
> I don't think the server side is well documented, but peeking at the
> code, I think you want this on the server:
>
> git config uploadpack.advertiseBundleURIs true
> git config bundle.version 1
> git config bundle.mode any
> git config bundle.foo.uri https://example.com/your.bundle
>
> And then the clients need to tell Git that they allow bundle transfers:
>
> git config --global transfer.bundleURI true
>
> I'm not sure if we'd eventually flip the client-side switch to "true" by
> default (which is what you'd need for this to happen without any user
> participation at all).
>
> One gotcha there is that clients are now accessing an arbitrary URL
> provided by the server, so there are cross-site security implications.
> It might make more sense to allow only relative URLs without ".." (so if
> I fetched from https://example.com/foo.git, the server could use only
> the relative "bundles/bar.bundle", which would then be found at
> https://example.com/foo.git/bundles/bar.bundle").
>
> -Peff

It wasn't clear to me what the <id> (bundle.foo in your case) referred
to. Where did 'foo' come from?

Anyway if people are taking suggestions for UX I'll give my $0.02:
git clone --try-bundle, with --bundle-uri overriding, to allow the
client to ask the server for bundles that satisfy their request.