Git clone all the things

TL;DR you can now run "git clone https://log.pfad.fr" to subscribe to the source of this log.

After playing with flake.nix, I noticed that I didn't want to hardcode my forge URL in the flake.nix file, just like I prefer to use a domain I control for go modules (where it is usually referred to as "vanity URL"):

So I dug to understand if and how I could use my domain for the flake inputs (while I am to lazy to self-host a code forge):

-    vanitydoc.url = "git+https://codeberg.org/pfad.fr/vanitydoc.git";
+    vanitydoc.url = "git+https://code.pfad.fr/vanitydoc";

Going down the rab-git hole

Under the hood, nix is performing a git clone, so the problem moves to telling git how to look for the repository somewhere else. I remembered having seen some "warning: redirecting to ..." when performing a git clone, so I thought that I could put a simple HTTP redirection from "https://code.pfad.fr/vanitydoc.git" to the actual forge URL "https://codeberg.org/pfad.fr/vanitydoc.git". However, git failed with:

remote: 404 page not found

To get a more verbose output, set the GIT_CURL_VERBOSE environment variable to 1. It shows that git actually fetches an "augmented URL": https://code.pfad.fr/vanitydoc.git/info/refs?service=git-upload-pack. Redirecting the `.../info/refs` path instead of the root path led to the next error:

fatal: unable to update url base from redirection: asked for: ...

Maintaining the query parameters "?service=git-upload-pack" fixes the issue (and I can drop the ".git" suffix since the redirection does not conflict with the documentation anymore)!

git clone https://code.pfad.fr/vanitydoc
Cloning into 'vanitydoc'...
warning: redirecting to https://codeberg.org/pfad.fr/vanitydoc.git/
remote: Enumerating objects: ...

So if you want to redirect a git repository, make sure to redirect the info/refs path and keep the query string:

From: https:///info/refs?service=git-upload-pack
To:   https:///info/refs?service=git-upload-pack

The flake.nix now relies on a domain I control, so moving forges should not be a problem in the future.

Static hosting of a git repository

After a night of sleep, I thought that I could also expose the source of this log under https://log.pfad.fr. During my previous adventures, I stumbled upon the git documentation about the "Dumb HTTP protocol".

Since I only want to expose the main branch, I added the following steps to the build pipeline of this log:

• make a "bare clone" of the "main" branch of the current git repository
• update the server info (recommended by the git documentation)
• copy the info and objects folders as well as the HEAD and packed-refs files to the root folder exposed by my static web server (I ignore the empty branches, hooks and refs folders, as well as some placeholder files)

git clone --bare . -b main --single-branch dist/bare

cd dist/bare
git update-server-info
rsync --archive info objects HEAD packed-refs ../http/

So you can now clone this log to subscribe to the source of it (articles are in the "content" folder):

git clone https://log.pfad.fr

Further reading on subscribing via git (accessible via the gemini protocol):

📆 2023-10-24