gitolite/doc/cust.mkd

customising gitolite

Much of gitolite (g3)'s functionality comes from programs and scripts that are not considered "core". This keeps the core simpler, and allows you to enhance gitolite for your own purposes without too much fuss. (As an extreme example, even mirroring is not in core now!)

This document will tell you about the types of non-core programs, and how/where to install your own. (Actually writing the code is described in the [developer notes][dev-notes] page).

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TOC

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introduction

There are 5 basic types of non-core programs.

• Commands can be run from the shell command line. Among those, the ones listed in the COMMANDS hash of the rc file can also be run remotely.
• Hooks are standard git hooks.
• Sugar scripts change the conf language for your convenience. The word sugar comes from "syntactic sugar".
• Triggers are to gitolite what hooks are to git. I just chose a different name to avoid confusion and constant disambiguation in the docs.
• VREFs are extensions to the access control check part of gitolite.

[Here][non-core] is a list of non-core programs shipped with gitolite, with some description of each.

locations

default/primary location of non-core programs

Regardless of how you installed gitolite, gitolite query-rc GL_BINDIR will tell you where the programs reside. Within that directory, the locations of non-core programs are:

• commands for commands.
• syntactic-sugar for sugar scripts.
• triggers and lib/Gitolite/Triggers for triggers ([this][triggers] will explain the difference).
• VREF for [VREFs][vref].

#localcode alternate location -- the LOCAL_CODE rc variable

If you want to add new non-core programs to your installation, or override the shipped non-core programs with your own versions, it's easy enough to simply copy your programs to the appropriate directory above, but then they'd get wiped out on the next upgrade.

A simple, "git-ish", method is to maintain a "local" branch in your clone of the gitolite source repo and make your changes there. Maintain them using rebase or merge when you 'git pull' gitolite itself, then use the rebased or merged "local" as the source for your gitolite upgrades. Works very nicely, and uses nothing but your git knowledge.

Sadly, it doesn't work for people installing from RPMs/DEBs; their "primary location" has already been setup, so any site-local customisations have to be done elsewhere.

This is where LOCAL_CODE comes in. If you define the LOCAL_CODE rc variable, then its value (please use a FULL path) describes a location where you can have any or all of these subdirectories:

• commands
• hooks/common
• syntactic-sugar
• triggers and lib/Gitolite/Triggers
• VREF

You might have noticed there's a new hooks/common directory here so you can add hooks also using this mechanism. Unlike the rest of the directories, adding new hooks to hooks/common requires that you follow up with gitolite setup, or at least gitolite setup --hooks-only.

#pushcode managing custom code via the gitolite-admin repo

The location given in LOCAL_CODE could be anywhere on disk.

However, if you point it to someplace inside $GL_ADMIN_BASE (i.e., $HOME/.gitolite), then you can version those programs using the gitolite-admin repo.

I suggest using a directory called "local-code" within the gitolite-admin repo that contains as much of the above directory structure you need. If you do that, then this is what you'd have in the rc file:

LOCAL_CODE                  =>  "$ENV{HOME}/.gitolite/local-code",

When you do this, gitolite takes care of everything automatically, including running gitolite setup --hooks-only when you change any hooks and push. However, if you do this, anyone who can push changes to the admin repo will effectively be able to run any arbitrary command on the server.

types of non-core programs

#commands gitolite "commands"

Gitolite comes with several commands that users can run. Remote users run commands by saying:

ssh git@host command-name [args...]

while on the server you can run

gitolite command [args...]

Very few commands are designed to be run both ways, but it can be done, by checking for the presence of env var GL_USER.

You can get a list of available commands by using the help command. Naturally, a remote user will see a much smaller list than the server user.

You allow a command to be run from remote clients by adding its name to (or uncommenting it if it's already added but commented out) the COMMANDS hash in the [rc][] file.

#hooks hooks and gitolite

You can install any hooks except these:

• (all repos) gitolite reserves the update hook. See the "update hook" section in [dev-notes][] if you want additional update hook functionality.

• (gitolite-admin repo only) gitolite reserves the post-update hook.

How/where to install them is described in detail in the "locations" section above, especially [this][localcode] and [this][pushcode]. The summary is that you put them in the "hooks/common" sub-directory within the directory whose name is given in the LOCAL_CODE rc variable.

#sugar syntactic sugar

Sugar scripts help you change the perceived syntax of the conf language. The base syntax of the language is very simple, so sugar scripts take something else and convert it into that.

That way, the admin sees additional features (like allowing continuation lines), while the parser in the core gitolite engine does not change.

If you want to write your own sugar scripts, please read the "your own sugar" section in [dev-notes][] first then email me.

triggers

Triggers have their own [document][triggers].

VREFs

VREFs also have their own [document][vref].