SINCE 1.5.0
Gitblit supports extending and enhacing the core functionality through plugins. This mechanism is very young and incomplete with few extension points, but you can expect it to evolve rapidly in upcoming releases.
The existing plugin mechanism is based on pf4j. Plugins are distributed as zip files and may include their runtime dependencies or may rely on the bundled dependencies of other plugins and/or Gitblit core.
The zip plugins are stored in ${baseFolder}/plugins and are unpacked on startup into folders of the same name.
A plugin defines it's metadata in the META-INF/MANIFEST.MF file:
Plugin-Class: com.gitblit.plugins.cookbook.CookbookPlugin
Plugin-Dependencies: foo, bar
Plugin-Id: gitblit-plugin
Plugin-Provider: John Doe
Plugin-Version: 1.0
In addition to extending Gitblit core, plugins can also define extension points that may be implemented by other plugins. Therefore a plugin may depend on other plugins.
Plugin-Dependencies: foo, bar
Plugins are controlled by the plugin SSH dispatch command. Only administrators have permission to use this dispatch command.
The pf4j plugin framework relies on a javac apt processor to generate compile-time extension information, so be sure to enable apt processing in your build process.
You can provide your own custom SSH commands by extending the DispatchCommand.
For some examples of how to do this, please see:
gitblit-cookbook-plugin (Maven project)
gitblit-powertools-plugin (Ant/Moxie project)
Gitblit's core SSH commands and those in the powertools plugin rely on use of ANSI border characters to provide a pretty presentation of data. Unfortunately, the fonts provided by Apple - while very nice - don't work well with ANSI border characters. The following public domain fixed-width, fixed-point, bitmapped fonts work very nicely. I find the 6x12 font with a line spacing of ~0.8 to be quite acceptable.