Facebook Buck is needed to compile the code, and an SQL database to house the review metadata. H2 is recommended for development databases, as it requires no external server process.

Getting the Source

Create a new client workspace:

  git clone --recursive https://gerrit.googlesource.com/gerrit
  cd gerrit

The --recursive option is needed on git clone to ensure that the core plugins, which are included as git submodules, are also cloned.


For details on how to build the source code with Buck, refer to: Building on the command line with Buck.

Configuring Eclipse

To use the Eclipse IDE for development, please see Eclipse Setup.

For details on how to configure the Eclipse workspace with Buck, refer to: Eclipse integration with Buck.

Mac OS X

On Mac OS X ensure "Java For Mac OS X 10.5 Upate 4" (or later) has been installed, and that JAVA_HOME is set to "/System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home". Check the installed version by running java -version and looking for build 1.6.0_13-b03-211. Versions of Java 6 prior to this version crash during the build due to a bug in the JIT compiler.

Site Initialization

After compiling (above), run Gerrit’s init command to create a testing site for development use:

  java -jar buck-out/gen/gerrit.war init -d ../test_site

Accept defaults by pressing Enter until init completes, or add the --batch command line option to avoid them entirely. It is recommended to change the listen addresses from * to localhost to prevent outside connections from contacting the development instance.

The daemon will automatically start in the background and a web browser will launch to the start page, enabling login via OpenID.

Shutdown the daemon after registering the administrator account through the web interface:

  ../test_site/bin/gerrit.sh stop


Running the Acceptance Tests

Gerrit has a set of integration tests that test the Gerrit daemon via REST, SSH and the git protocol.

A new review site is created for each test and the Gerrit daemon is started on that site. When the test has finished the Gerrit daemon is shutdown.

For instructions on running the integration tests with Buck, please refer to: Running integration tests with Buck.

Running the Daemon

The daemon can be directly launched from the build area, without copying to the test site:

  java -jar buck-out/gen/gerrit.war daemon -d ../test_site

Querying the Database

The embedded H2 database can be queried and updated from the command line. If the daemon is not currently running:

  java -jar buck-out/gen/gerrit.war gsql -d ../test_site

Or, if it is running and the database is in use, connect over SSH using an administrator user account:

  ssh -p 29418 user@localhost gerrit gsql

Debugging JavaScript

When debugging browser specific issues add ?dbg=1 to the URL so the resulting JavaScript more closely matches the Java sources. The debug pages use the GWT pretty format, where function and variable names match the Java sources.


To use the GWT DETAILED style the package must be recompiled and ?dbg=1 must be omitted from the URL:

  mvn package -Dgwt.style=DETAILED

Release Builds

To create a release build for a production server, or deployment through the download site:


If AsciiDoc isn’t installed or is otherwise unavailable, the WAR can still be built without the embedded documentation by passing an additional flag:

  ./tools/release.sh --without-documentation

Client-Server RPC

The client-server RPC implementation is gwtjsonrpc, not the stock RPC system that comes with GWT. This buys us automatic XSRF protection. It also makes all of the messages readable and writable by any JSON implementation, facilitating "mashups" and 3rd party clients.

The programming API is virtually identical, except service interfaces extend RemoteJsonService instead of RemoteService.

Why GWT?

We like it. Plus we can write Java code once and run it both in the browser and on the server side.

Google Web Toolkit:

Apache SSHD: