Helm

Charts, Repos and Releases

Let’s start clarifying some definitions.

• Chart is a Helm package of pre-configured Kubernetes resources. It contains all of the resource definitions necessary to run an application, tools, or service inside of a K8S cluster. It’s the equivalent of a Hombrew formula.
• Repository is the place where charts can be collected and shared.
• Release is an instance of a chart running in a K8s cluster.

Helm is a tool for installing charts into K8s, creating a new release for each installation.

Useful Helm client commands:

View available charts

helm search hub

helm search repo

Search stuff

help search repo redis

Update repo info (list of packages)

helm repo update

Get info of chart

help show chart <packageName>

Install a chart with the defaults

helm install <releaseName> <packageName>

Whenever you install a chart, a new release is created. So one chart can be installed multiple times into the same cluster. And each can be independently managed and upgraded.

After installing the redis helm chart

According to Helm docs it installs k8s resources in a specific order: Namespace, NetworkPolicy, ResourceQuota, LimitRange, etc

Another installation example:

Install a chart with customizations

helm show values <packageName> para conocer ver las variables configurables

Luego con un archivo YAML

helm install -f values.yaml <packageName> <releaseName>

Get status of a release

helm status <releaseName>

Uninstalling the chart

helm delete <releaseName>

Check what have been release

helm list

Upgrade your application

helm upgrade <RELEASE> <CHART>

Create your own chart

helm create <chart-name>

Next steps

Here is a good online resource for hacking around Kubernetes and Helm