CGIT 0.10 Brings Lua Scripting Support, New Features

CGIT 0.10 has been released and it's a rather exciting and major update for just being a web-based Git viewer.

The CGIT 0.10 release happened this morning and it brings Lua scripting support, authentication support, email filtering support, a revamp of the filer infrastructure, support for the rawdiff command, and tons of other changes.

The CGIT 0.10 release announcement with details on all of the new features and changes can be found via the mailing list announcement.

Jason Donenfeld, one of the developers leading CGIT development and the one who announced today's 0.10 release, also wrote into Phoronix with more details on this latest CGIT work, particularly surrounding the Lua scripting engine support.

I thought I'd let you know some of the interesting things surrounding the recent CGit 0.10 release. A couple weeks ago, someone posted to our list a patch that added Gravatars beside author names. It was in C, and was something of a hack, and quite specific to Gravatar. Simultaneously, the kernel.org folks let us know that they're in the process of developing some kind of new profile key infrastructure, and they want to tie cgit's display of author and committer names and emails to this.

So we added a very simple filter, using our existing filter infrastructure, that pipes author names and emails out to an external shell script or other executable, and reads back in the script's modifications. We've supported doing this with things like the about pages, for displaying markdown formatted text, or showing syntax highlighted source code, so this itself wasn't a very big innovation.

The problem we faced, however, was that fork()ing and exec()ing a shell script for each and every commit in a log is obscenely inefficient. So, we decided to rework our filter framework to include support for Lua scripts.

This was my first time ever embedding Lua into a program, but I must say, the API was super simple and a joy to work with. CGit now has the ability to load and run Lua scripts, without having to fork() and exec(), and it can keep the same Lua script around in memory for multiple invocations of it. I reimplemented the original Gravatar patch in Lua, and compared it to the original integrated-in-the-main-codebase C version posted, and I found no performance differences. Success! We integrate with both Lua and LuaJIT for maximum performance. Lua scripts can be used with any of our filters, and our new framework is easy to extend, so should anybody want to add other languages into the runtime (optionally, of course), it's easy to do so. So now, the kernel.org folks will be able to write a simple Lua script for integrating their cgit install with the rest of their infrastructure.

Interestingly, the developer of repo.or.cz, one of the oldest public git repository websites, has noticed our excellent relationship with kernel.org, and is considering adding CGit support to repo.or.cz. We've already made some enhancements for them as well.

All this Lua capability allowed me to scratch another itch -- proper authentication support. We now support an authentication filter, which allows a simple Lua script to selectively password protect -- or use any other form of authentication -- any part of CGit it chooses. Our included example script is pretty advanced, supporting HMAC'd cookies and a username/password form-based authentication scheme for chosen repositories.