Installing charts in Kubernetes - Step-by-Step CLI Walkthrough

Introduction

Installing charts helps you add ready-made applications to your Kubernetes cluster easily. Charts package all the resources needed to run an app, so you don't have to create each part manually.

When you want to deploy a database like MySQL quickly without writing all Kubernetes files.

When you need to add monitoring tools like Prometheus to your cluster with minimal setup.

When you want to install a web server such as Nginx with default settings fast.

When you want to try out an application without configuring every detail yourself.

When you want to manage app upgrades and rollbacks easily using a package system.

Commands

This command adds the Bitnami chart repository to Helm so you can access many ready-to-use charts from Bitnami.

Terminal

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

Expected Output

"bitnami" has been added to your repositories

This updates your local list of charts from all added repositories to make sure you have the latest versions.

Terminal

helm repo update

Expected Output

Hang tight while we grab the latest from your chart repositories...

...Successfully got an update from the "bitnami" chart repository

Update Complete.

This installs the Nginx chart from Bitnami repository into your Kubernetes cluster with the release name 'my-nginx'.

Terminal

helm install my-nginx bitnami/nginx

Expected Output

NAME: my-nginx

LAST DEPLOYED: Sat Jun 10 12:00:00 2023

NAMESPACE: default

STATUS: deployed

REVISION: 1

NOTES:

1. Get the application URL by running these commands:

  export POD_NAME=$(kubectl get pods --namespace default -l app.kubernetes.io/name=nginx -o jsonpath="{.items[0].metadata.name}")

  echo "Visit http://127.0.0.1:8080 to use your application"

  kubectl port-forward $POD_NAME 8080:80

→

--namespace - Specify the Kubernetes namespace to install the chart into

→

--set - Override chart default values during installation

This command checks the status of pods in your cluster to verify that the Nginx pod is running after installation.

Terminal

kubectl get pods

Expected Output

NAME                             READY   STATUS    RESTARTS   AGE

my-nginx-nginx-5d7f9d7f7b-abcde 1/1     Running   0          30s

Key Concept

If you remember nothing else from this pattern, remember: Helm charts let you install complex apps on Kubernetes with one simple command.

Common Mistakes

Trying to install a chart without adding the repository first

Helm won't find the chart because it doesn't know where to look for it.

Always add the chart repository using 'helm repo add' before installing charts from it.

Not running 'helm repo update' after adding a new repository

Your local list of charts will be outdated, so you might not get the latest chart versions.

Run 'helm repo update' to refresh your chart list before installing.

Not checking pod status after installation

You might think the app is running when it actually failed to start.

Use 'kubectl get pods' to confirm the app pods are running properly.

Summary

Add a chart repository with 'helm repo add' to access ready-made apps.

Update your local chart list with 'helm repo update' to get the latest versions.

Install an app using 'helm install' with a release name and chart name.

Verify the app is running by checking pods with 'kubectl get pods'.