Setting up Helm 3 (Preview)

Warning

Helm 3 is not yet officially supported by Zero to JupyterHub. Upgrades from Helm 2 are not handled. Helm 3 should only be used for testing new clusters. Please report any bugs on the GitHub issue tracker.

Helm, the package manager for Kubernetes, is a useful tool for: installing, upgrading and managing applications on a Kubernetes cluster. Helm packages are called charts. We will be installing and managing JupyterHub on our Kubernetes cluster using a Helm chart.

Charts are abstractions describing how to install packages onto a Kubernetes cluster. When a chart is deployed, it works as a templating engine to populate multiple yaml files for package dependencies with the required variables, and then runs kubectl apply to apply the configuration to the resource and install the package.

Helm 3 includes several major breaking changes including:

• The Tiller server component is removed. Helm now uses the default Kubernetes security mechanisms. This greatly improves security.

• Uses a three way instead of two way strategic merge. This may affect how upgrades are merged into an existing deployment.

See the Helm 3 FAQ for more information.

Installation

While several methods to install Helm exist, the simplest way to install Helm is to run Helm’s installer script in a terminal:

curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash

Helm 3 uses the same security mechanisms as other Kubrenetes clients such as kubectl. Since it does not have a separate server process no special steps are required to secure it.

Verify

You can verify that it is installed properly by running:

helm list

You should see an empty list since no Helm charts have been installed:

NAME    NAMESPACE       REVISION        UPDATED STATUS  CHART   APP VERSION

Next Step

Helm 3 will not automatically create a namespace for JupyterHub. If you are using a namespace other than default create it now:

kubectl create namespace $NAMESPACE

Now continue with Setting up JupyterHub.