Stark & Wayne

2 min read> Helm 3 - How Do I Do Helm 2 Stuff?

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Helm 3 was recently introduced which changed many of the internal bits within the CLI which are not fully backward compatible to those using Helm 2. Fear not, with a couple minor tweaks you can continue to use the Helm charts you know and love!

If you are a maintainer of Helm charts you should probably start with https://helm.sh/docs/faq/#changes-since-helm-2 to see how the changes impact you.

This post, however, focuses on the user experience of consuming charts other folks maintain.  Below we'll review how to install the PostgreSQL chart.

Using Helm install is Now 2 Steps

Helm 2

In the time before Helm 3 installing a chart was as simple as:

helm install stable/postgresql

This assumed you would be using https://github.com/helm/charts as your chart repository.

Helm 3

It is fairly common to deploy helm charts by specifying the absolute url to a chart. With Helm 3+ you'll need to do helm installs in two steps:

Add the chart repo to Helm:

helm repo add bitnami https://charts.bitnami.com

Note that there is a newer chart repository at https://hub.helm.sh.

Install the chart:

helm install bitnami/postgresql --version 8.1.2

Using the old charts with Helm 3

If you still wish to use the charts in https://github.com/helm/charts with Helm 3, download the repo and specify the file path:

git clone https://github.com/helm/charts.git
cd charts/stable

helm install ./postgresql

Namespace is no longer automatically created

In Helm v2 you could specify a namespace during an install and if it didn't exist, the namespace would be created automatically:

➜  helm2 install postgresql --name postgres2 --namespace=purple

The purple namespace would be created automatically:

NAME              STATUS   AGE
default           Active   83m
kube-node-lease   Active   83m
kube-public       Active   83m
kube-system       Active   83m
purple            Active   6m27s

Under Helm v3+ the orange namespace is not created:

➜  helm3 install postgres3 ./postgresql --namespace=orange
Error: create: failed to create: namespaces "orange" not found

You'll need to remember to create the namespace first until that functionality is added to many of the older charts.

No Tiller

You no longer need to do the helm init dance, no server side components should make Helm easier to manage for operators in the long run.  Hurray!

Miscellaneous

There are a few additional changes that happened with Helm 3:

  • helm del is an alias for helm uninstall which no longer has a --purge option since the uninstall cleans up the references.
  • When performing an install, there is no longer a --name option, the usage is helm install [NAME] [CHART] [flags] so simply provide the name as the first parameter to the install.
Find more great articles with similar tags helm chart kubernetes author-cweibel