Purpose of this plugin is to use Gitblit as web-based viewer (i.e. GitWeb replacement) on top of Gerrit Code Review.
As pre-requisites you need to make a custom-build of Gitblit and Wicket: the standard JARs downloaded from a public Maven repository aren't enough as they are missing some specific build parameters and constraints (i.e. shaded-jar) that are needed for a Gerrit plugin to work properly.
You need to clone Gitblit from GitHub and build it locally using the installMaven ANT target.
$ git clone https://github.com/gitblit/gitblit.git
$ cd gitblit && git checkout master
$ ant -DresourceFolderPrefix=static installMaven
This gitblit plugin is built with Bazel. Only the Gerrit in-tree build is supported.
Clone or link this plugin to the plugins directory of Gerrit's source tree.
  git clone https://gerrit.googlesource.com/gerrit
  git clone https://gerrit.googlesource.com/plugins/gitblit
  cd gerrit/plugins
  ln -s ../../gitblit .
  rm external_plugin_deps.bzl
  ln -s gitblit/external_plugin_deps.bzl .
  cd ../
From Gerrit source tree issue the command:
  bazel build plugins/gitblit
The output is created in
  bazel-bin/plugins/gitblit/gitblit.jar
This project can be imported into the Eclipse IDE.
Add the plugin name to the CUSTOM_PLUGINS set in
Gerrit core in tools/bzl/plugins.bzl, and execute:
  ./tools/eclipse/project.py
In order to use GitBlit as GitWeb replacement, run the Gerrit init again and answer 'Y' when asked during the Gitblit-specific initialisation.
Example:
*** GitBlit Integration
***
Do you want to use GitBlit as your GitWeb viewer? [Y/n]? y
Link name                      [GitBlit]:
"Repositories" submenu title   [Repositories]:
"Activity" submenu title       [Activity]:
"Documentation" submenu title  [Documentation]:
"Search" submenu title (makes only sense to set if some projects are indexed in GitBlit; single dash unsets) [Search]:
"Browse" submenu title for the "Projects" top-level menu [Browse]: