Test your Nebari contribution

As you develop your contributions to the Nebari codebase, you will mainly be working with Python files, Terraform files, and occasionally Docker images. This page has some tips for testing your contributions to make sure it works as intended.

Test Nebari CLI commands

Test CLI manually

If you have an editable installation of Nebari, you can test your changes by running the Nebari CLI commands from within your development environment. For example, you can run nebari init and make sure it builds the nebari-config.yaml file without errors.

Test CLI with pytest

Nebari uses pytest to test the Python files and modules.

The unit test files are located in the tests directory. You can use the regular pytest commands to run them:

pytest tests/

ℹ️note

These tests are also triggered by the Nebari CI when you open pull requests.

Test the Nebari deployment (Terraform)

Test the deployment manually

If you update Terraform (and related) files in nebari/states, you can deploy Nebari locally to test if all the deployment steps execute successfully. Nebari uses Kind to create local Kubernetes clusters. Nebari ships with Kind, so you don't have to install it separately.

ℹ️note

Right now, local deployments can be done on Linux machines because of the nuances of how Docker works on macOS and Windows.

After you make changes, you can re-deploy your Nebari instance to test it manually.

Testing the deployment with pytest

The deployment and integration tests help us test various features of a local Nebari deployment on Kind, such as Dask Gateway, external integrations, state of the Kubernetes cluster, and more. You can run the integration and deployment tests located in the tests_deployment directory with:

pytest tests_deployment/

ℹ️note

These tests are also triggered by the Nebari CI when you open pull requests.

Debug Kubernetes clusters with k9s

Re-deploying Nebari after every change can be tedious, so we recommend using k9s to debug the running Kubernetes clusters. k9s is a terminal-based user interface that assists with navigation, observation, and management of applications in Kubernetes. k9s continuously monitors Kubernetes clusters for changes and provides shortcut commands to interact with the observed resources. It can help you review and resolve day-to-day issues in the deployed clusters quickly.

You can install k9s on macOS, Windows, and Linux with these instructions project's README.

For more details on using k9s, check out the documentation on debugging Nebari.

Cloud testing

Cloud deployments are the only way to truly test the complete Nebari infrastructure. To test on cloud Kubernetes, deploy Nebari in the normal way on the cloud, but make sure to:

• Install Nebari in the editable mode, so your changes are reflected in the deployment, and
• Use a development branch to specify the Docker images based on the latest development code in nebari-config.yaml.

🔥warning

Testing your contribution by deploying Nebari on the cloud (AWS, GCP, Azure, and Digital Ocean) can consume a lot of time and resources. Always prefer local testing when possible. It will be easier to debug, may be quicker to deploy, and is likely to be less expensive.

Automated CI tests with Cypress

We use Cypress to automate Nebari testing within a web browser environment. Cypress is an open source test automation tool for interactive web applications. We use it to test everything from the authentication process to JupyterHub integrations like Grafana monitoring.

It's integrated into the GitHub Actions tests.yaml workflow in the nebari-dev/nebari repository. You can also run it locally. To do so:

1. Navigate to the tests_e2e directory:

   cd tests_e2e

2. Install the necessary prerequisites:

   npm install

3. Set the following environment variables:

   export CYPRESS_BASE_URL=http://127.0.0.1:8000/
   export NEBARI_CONFIG_PATH=/Users/<name>/<path>/nebari-config.yaml
   export CYPRESS_EXAMPLE_USER_PASSWORD=<password>

   The CYPRESS_BASE_URL can point anywhere that you can access it. It can also be the URL of a Nebari cloud deployment.

   The NEBARI_CONFIG_PATH should point to the associated YAML file for that website. The tests will inspect the YAML file to understand which tests are relevant. It first checks security.authentication.type to determine what should be available on the login page, and how to test it. If the login type is 'password' then it uses the value in CYPRESS_EXAMPLE_USER_PASSWORD as the password. The default username is example-user, but it can be changed by setting the CYPRESS_EXAMPLE_USER_NAME environment variable.

4. Open the Cypress UI where you can run the tests manually and see the actions in the browser:

npm run cypress:open

ℹ️note

These tests are heavily state-dependent, so any changes or use of the deployed Nebari instance could affect the results.

Develop and test nebari-docker-images

All Nebari docker images are located in nebari-dev/nebari-docker-images. You can build any image locally. Additionally, when you open pull requests on the main nebari-dev/nebari repository, each Docker-build will be tested.

docker build -f Dockerfile.<filename> .

ℹ️note

There is a GitHub Actions workflow that will build these images and push to Docker Hub whenever a change is made to the relevant files on GitHub.

Update docker images

You can modify the images, for example, the JupyterLab default docker image, and run the resulting configuration with:

docker run -p 8888:8888 -it <image-sha> jupyter lab --ip=0.0.0.0

Then open the localhost (127.0.0.1) link displayed in the terminal:

[I 2021-04-05 17:37:17.345 ServerApp] Jupyter Server 1.5.1 is running at:
...
[I 2021-04-05 17:37:17.346 ServerApp]  or http://127.0.0.1:8888/lab?token=8dbb7ff1dcabc5fab860996b6622ac24dc71d1efc34fcbed
...
[I 2021-04-05 17:37:17.346 ServerApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).

To debug the image directly, you can run:

docker exec -ti <container-name>

Linting Dockerfiles

To lint Dockerfiles, we use a tool called Hadolint. Hadolint is a Dockerfile linter that helps you discover issues with the Dockerfiles and recommends some best practices being followed. Nebari CI automates Hadolint code reviews on every commit and pull request to nebari-dev/nebari-docker-images, reporting code style and error-prone issues.

To run Hadolint locally you can either install it locally or use a container image, with the instructions in the installation documentation for Hadolint. The .hadolint.yml on the root directory defines the ignored rules.

Run Hadolint on Dockerfiles with:

hadolint ./Dockerfile.conda-store
hadolint ./Dockerfile.dask-gateway
hadolint ./Dockerfile.dask-worker
hadolint ./Dockerfile.jupyterhub
hadolint ./Dockerfile.jupyterlab

Hadolint will report error, warning, info, and style while linting Dockerfiles. In case of an error, the CI will fail.

Additional tips

Use a development branch

To use (initialize, deploy, and more) Nebari from a development branch such as main set the environment variable NEBARI_GH_BRANCH before running Nebari commands:

export NEBARI_GH_BRANCH=main

Then nebari init will create a nebari-config.yaml file containing, for example, nebari/nebari-jupyterlab:main which is the Docker image built based on the Dockerfiles specified in the main branch of the Nebari repo.

nebari deploy can also use NEBARI_GH_BRANCH to create GitHub/GitLab Actions workflows which install the development branch of Nebari for the deployment steps.

ℹ️note

If you want to use the development version of Nebari for your init and deploy steps, but want your resulting deployment to be based on a full release version, don't set the NEBARI_GH_BRANCH environment variable.

If you do so, Docker tags and workflow pip install nebari commands will be based on the Nebari version specified in the nebari/version.py file. These tags and releases may not yet exist (perhaps if the version has been updated to include a beta/dev component which has not been released). You may need to manually modify the nebari-config.yaml file to 'downgrade' the tags to a full release version.

Kubernetes version check for cloud providers

When nebari init <cloud provider> is called, it checks that the --kubernetes-version provided is supported by the preferred cloud provider. This flag is optional and if not provided, the kubernetes_version is set to the most recent Kubernetes version available. This is achieved by using the cloud provider's SDK, so you need to set their appropriate credentials as well.

To get around this, set the NEBARI_K8S_VERSION environment variable with:

export NEBARI_K8S_VERSION=1.20