Forks

2024-11-29 by Pere Lev

Concept

Before we begin: As always, my task board is available. It seems some disk space problem is taking apart my VPS, including the SSL certs, so you might get a warning about them being expired. I'm starting to wonder if it's a good idea for me to find an arrangement where someone else manages the services that I use. Like, I still want Nextcloud etc. etc. all the self-hosted appps I use, I just don't want to be a sysadmin, and I'm ok with financially supporting someone else who, unlike me, enjoys that work and is happy to be doing it. Anyone has ideas?

The last post talked about issue tracker migration. This post is going to talk about something quite similar - repository forks! Vervis never had them in the UI until just now.

Here's a brief summary of how issue tracker migration works:

1. Each tracker publishes its data to make it available for copying
2. When you create a tracker, you can choose to fill it with a copy of another tracker's data

I added another piece on top:

• When the request for the new tracker (or repository or any other resource) is sent, and when it's fulfilled and the tracker gets created, the old tracker is notified on these events
• Therefore the tracker/resource tracks and lists its "children" i.e. resources created as copies of it - for repos, we call these children forks

And for repos specifically,

• Each repo publishes its F3 object, and of course its Git content for cloning
• When creating repo B as a fork of repo A, repo B git fetches from repo A
• While tracker migration works only between remote trackers, repo forking can be done both local and remote

NOTE: The Git repo implementation in Vervis is still buggy - I intend to fix the bugs in the 2025 roadmap - for this task I implemented and fixed just enough pieces for repo creation and forking to work.

Purpose

I often see people complain about the limitations of the fork-and-PR based workflow. With forks being implemented into Vervis and ForgeFed, I imagine you may be asking "Why are you imitating the limited GitHub workflow?"

Here's the answer: ForgeFed is a specification, not an application. It really tries to be flexible. ForgeFed supports sending PRs via forks, branches and simple patch files, which means the classic patch-sending flows are perfectly possible as well. Forks in ForgeFed and Vervis aren't about imitating the GH workflow - they're just a way to support easy migration, and track copies and derivatives of content. The actual workflows are up to the specific forge.

For example, imagine that personal-forks-just-for-PRs had their own namespace. Or that forking is allowed for easy copying and migration but isn't used for PRs. It's really up to the actual forge software. As long as it implements the ForgeFed event sequences, it can communicate with any other forge, even if their UIs offer diffrent workflows.

How to Use

Just like with issue tracker migration: When creating a repo, you can optionally specify an existing repo URI - local or remote - and the new repo will be created as a fork of the existing one.

Note that I tested this only for Git repos - expect (more) bugs for Darcs.

This repository on the Fig instance has been created as a fork of repo from the Grape instance. If you click it, and then go to its Forks tab (which currently serves only a JSON object), you can see the URI of the Fig repo listed as a known fork.

Implementation

• Repo: UI, Client and S2S preparations for Forking
• UI: Remote Actor: If it's a repo, display a Fork link
• Vocab: Repo: Specify origin property
• Repo: Serve F3 representation
• UI: Repo: Display fork origin repo
• DB, UI, Vocab: Repo: Serve forks collection
• Factory-based Repo creation, with local and remote fork support
• S2S: Repo: Create: Record the fork attempt
• S2S: Component: Accept: If it's a Factory accepting a Create, record the fork
• UI: Factory: Allow to toggle repo support

Funding

I really want to thank NLnet for funding this work!

Our current grant is about to end, but we're also working on the roadmap of the new grant, so exciting stuff is expected for 2025, more news soon :)

See It in Action

This time I didn't record a video demo. If you want to play with things yourself, you can create account(s) on the demo instances - fig, grape, walnut - and try creating repos and forks.

If you encounter any bugs, let me know! Or open an issue

Comments

Come chat with us on Matrix!

And we have an account for ForgeFed on the Fediverse: https://floss.social/@forgefed

Right after publishing this post, I'll make a toot there to announce the post, and you can comment there :)