AKS Helm Kubernetes

Helm Commands

Action Command to Run
To list your releases helm list
To install a Releasehelm install [release] [chart]
Upgrade a Release revisionhelm upgrade [release] [chart]
Rollback to a Release revisionhelm rollback [release] [revision]
Display Release historyhelm history [release]
Display Release statushelm status [release]
Display details of a Releasehelm get all [release]
Uninstall a Releasehelm uninstall [release]
Display the manifest of the releasehelm get manifest [release]

I’ve added some examples below with context.

Couple of things to remember:-

What is a Chart?

A chart is the definition of your application.

What is a helm release?

A release is when you deploy your application using helm and it creates an instance of your chart running in the k8s cluster.

What is a Release revision?

A revision is when you make an update to one or more of your templates and redeploy it to the existing instance of your application. This is not a new release, it’s just a revision of your existing Release. If you were to add additional templates, this would not be a Release revision. This would be considered a Chart version change.

When do I change the Chart version ?

Carrying on from the previous question about a Release revision. Just updating an existing template with a change would not require you to change the Chart Version, it would only be a revision of the existing chart. However, if you needed to add a volume to the templates, or an additional service, etc.. then that would trigger you to change the Chart version.

Examples

Helm list – show all deployed charts

Command and Example: Helm list

Helm install – install a chart

Command: helm install release chart

Example: helm install derek run-test

To help understand this one. The release is the name you give it so in this case I called the release derek and the chart I’m deploying is called run-test, so that means the folder the chart is in is called run-tests. This is a little application I run to… yep, you guessed it, it runs tests!

Helm upgrade – upgrades/updates an existing deploy chart

Command: helm upgrade release chart

Example: helm upgrade derek run-tests

I’ve added an additional configmap to the chart and then upgraded to that revision. You can see that the revision number has increased.

Helm history – shows you the history of the release

Command: helm history release

Example: helm history derek

Helm status – shows the release status

Command: helm status release

Example: helm status derek

Helm get all – shows all the information for the release

Command: helm get all release

Example: helm get all derek

Helm uninstall – removes the release from the cluster

Command: helm uninstall release

Example: helm uninstall derek

and the release is removed.

Helm get manifest – gets the manifest that has been deployed.

Command: helm get manifest release

Example: helm get manifest derek

This command will show you the deployment with all the templates displayed.