Gerrit Deployment on Kubernetes

Container images, configurations and a Kubernetes Operator for installing Gerrit on Kubernetes.

Deploying Gerrit on Kubernetes

A Gerrit Operator can be used to install and operate Gerrit in a Kubernetes cluster. The documentation describes how to build and deploy the Gerrit Operator and how to use it to install Gerrit.

Docker images

This project provides the sources for docker images used by the Kubernetes deployment. The images are also provided on Dockerhub.

The project also provides scripts to build and publish the images so that custom versions can be used. This requires however a docker registry that can be accessed from the Kubernetes cluster, on which Gerrit will be deployed. The functionality of the scripts is described in the following sub-sections.

Building images

To build all images, the build-script in the root directory of the project can be used:

./build

If a specific image should be built, the image name can be specified as an argument. Multiple images can be specified at once:

./build gerrit git-gc

The build-script usually uses the latest-tag to tag the images. By using the --tag TAG-option, a custom tag can be defined:

./build --tag test

The version of Gerrit built into the images can be changed by providing a download URL for a .war-file containing Gerrit:

./build --gerrit-url https://example.com/gerrit.war

The version of a health-check plugin built into the images can be changed by providing a download URL for a .jar-file containing the plugin:

./build --healthcheck-jar-url https://example.com/healthcheck.jar

The build script will in addition tag the image with the output of git describe --dirty.

The target platform for the image build can be specified by using the --platform PLATFORM option. This allows you to build images for different architectures such as ARM or x86. By default, the platform is set to linux/amd64.

./build --platform linux/arm64

The single component images inherit a base image. The Dockerfile for the base image can be found in the ./base-directory. It will be automatically built by the ./build-script. If the component images are built manually, the base image has to be built first with the target base:latest, since it is not available in a registry and thus has to exist locally.

Publishing images

The publish script in the root directory of the project can be used to push the built images to the configured registry. To do so, log in first, before executing the script.

docker login <registry>

To configure the registry and image version, the respective values can be configured via env variables REGISTRY and TAG. In addition, these values can also be passed as command line options named --registry and --tag in which case they override the values from env variables:

./publish <component-name>

The <component-name> is one of: apache-git-http-backend, git-gc, gerrit or gerrit-init.

Adding the --update-latest-flag will also update the images tagged latest in the repository:

./publish --update-latest <component-name>

Running images in Docker

The container images are meant to be used by the Kubernetes deployment provided in this project. The images are thus not designed to be used in a standalone setup. To run Gerrit on Docker use the docker-gerrit project.

Running tests

The tests are implemented using Python and pytest. To ensure a well-defined test-environment, pipenv is meant to be used to install packages and provide a virtual environment in which to run the tests. To install pipenv, use brew:

brew install pipenv

More detailed information can be found in the pipenv GitHub repo.

To create the virtual environment with all required packages, run:

pipenv install

To run all tests, execute:

pipenv run pytest

Some tests will need to create files in a temporary directory. Some of these files will be mounted into docker containers by tests. For this to work make either sure that the system temporary directory is accessible by the Docker daemon or set the base temporary directory to a directory accessible by Docker by executing:

pipenv run pytest --basetemp=/tmp/k8sgerrit

By default the build of the container images will not use the build cache created by docker. To enable the cache, execute:

pipenv run pytest --build-cache

Slow tests may be marked with the decorator @pytest.mark.slow. These tests may then be skipped as follows:

pipenv run pytest --skip-slow

There are also other marks, allowing to select tests (refer to this section).

To run specific tests, execute one of the following:

# Run all tests in a directory (including subdirectories)
pipenv run pytest tests/container-images/base

# Run all tests in a file
pipenv run pytest tests/container-images/base/test_container_build_base.py

# Run a specific test
pipenv run \
  pytest tests/container-images/base/test_container_build_base.py::test_build_base

# Run tests with a specific marker
pipenv run pytest -m "docker"

For a more detailed description of how to use pytest, refer to the official documentation.

Test marks

docker

Marks tests which start up docker containers. These tests will interact with the containers by either using docker exec or sending HTTP-requests. Make sure that your system supports this kind of interaction.

incremental

Marks test classes in which the contained test functions have to run incrementally.

integration

Marks integration tests. These tests test interactions between containers, between outside clients and containers.

slow

Marks tests that need an above average time to run.

structure

Marks structure tests. These tests are meant to test, whether certain components exist in a container. These tests ensure that components expected by the users of the container are present in the containers.

Contributing

Contributions to this project are welcome. If you are new to the Gerrit workflow, refer to the Gerrit-documentation for guidance on how to contribute changes.

The contribution guidelines for this project can be found here.

Roadmap

The roadmap of this project can be found here.

Feature requests can be made by pushing a change for the roadmap. This can also be done to announce/discuss features that you would like to provide.

Contact

The Gerrit Mailing List can be used to post questions and comments on this project or Gerrit in general.