gitolite/doc/dev-notes.mkd

notes for developers

Gitolite has a huge bunch of existing features that gradually need to moved over. Plus you may want to write your own programs to interact with it.

Here are some random notes on developing hooks, commands, triggers, and sugar scripts.

environment variables and other inputs

In general, the following environment variables should always be available:

GL_BINDIR
GL_REPO_BASE
GL_ADMIN_BASE

Commands invoked by a remote client will also have GL_USER set. Hooks will have GL_REPO also set.

Finally, note that triggers get a lot of relevant information from gitolite as arguments; see [here][triggers] for details.

APIs

the shell API

The following commands exist to help you write shell scripts that interact easily with gitolite. Each of them responds to -h so please run that for more info.

• gitolite access to check access rights given repo, user, type of access (R, W, ...) and refname (optional). Example use: src/commands/desc

• gitolite creator to get/check the creator of a repo. Example use: src/commands/desc

• gitolite git-config to check gitolite options or git config variables directly from gitolite's "compiled" output, (i.e., without looking at the actual repo.git/config file or using the git config command). Example use: none yet

• gitolite query-rc to check the value of an RC variable. Example use: src/commands/desc.

In addition, you can also look at the comments in src/Gitolite/Easy.pm (the perl API module) for ideas.

the perl API

...is implemented by Gitolite::Easy; the comments in src/Gitolite/Easy.pm serve as documentation.

writing your own...

...hooks

anything but the update hook

If you want to add your own hook, it's easy as long as it's not the 'update' hook. Just add it to $HOME/.gitolite/hooks/common and run gitolite setup.

The rest is between you and 'man githooks' :-)

update hook

If you want to add additional update hook functionality, do this:

• write and test your update hook separately from gitolite

• now add the code to src/VREF. Let's say it is called "foo".

• to call your new update hook to all accesses for all repos, add this to the end of your conf file:

  repo @all
      -       VREF/foo        =   @all
  

As you probably guessed, you can now make your additional update hooks more selective, applying them only to some repos / users / combinations.

Note: a normal update hook expects 3 arguments (ref, old SHA, new SHA). A VREF will get those three, followed by at least 4 more. Your VREF should just ignore the extra args.

...commands

You can add your own commands. You can run them on the server (example, gitolite access). Then you can enable certain commands to be allowed to run by a remote user by adding them to the "COMMANDS" hash of the [rc][] file.

Commands are standalone programs, in any language you like. They simply receive the arguments you append. In addition, the env var GL_USER is available if it is being run remotely. src/commands/desc is the best example at present.

...trigger programs

Trigger programs run at specific points in gitolite's execution, with specific arguments being passed to them. See the [triggers][] page for details.

You can write programs that are both manually runnable as well as callable by trigger events, especially if they don't need any arguments.

..."sugar"

Syntactic sugar helpers are NOT complete, standalone, programs. They must include a perl sub called sugar_script that takes in a listref, and returns a listref. The listrefs point to a list that contains the entire conf file (with all [include][] processing already done). You create a new list with contents modified as you like and return a ref to it.

There are a couple of examples in src/syntactic-sugar.