Skip to content

Lab9-Helm-basics.md

Latest commit

 

History

History
158 lines (102 loc) · 3.22 KB

Lab9-Helm-basics.md

File metadata and controls

158 lines (102 loc) · 3.22 KB

Lab Title:
Using a Pre-Made Helm Chart: Customization, Upgrade, Rollback, and Cleanup

Objective:
Learn how to deploy a ready-made Helm chart, modify its configuration, upgrade the release, roll back to a previous version, and then uninstall the release—all using Helm v3.

Install Helm

Linux/MacOS

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

MacOS ( Homebrew )

brew install helm

Windows

choco install kubernetes-helm

Chart Used:
We will use the Bitnami NGINX chart available from the Bitnami repository.

Step 1: Add the Bitnami Repository and Update

  1. Open your terminal.

  2. Add the Bitnami Helm repository:

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

  3. Update your local repository cache:

    helm repo update

Step 2: Install the Pre-Made NGINX Chart

  1. Install the NGINX chart with a release name (we’ll use “my-nginx”) in the default namespace:

    helm install my-nginx bitnami/nginx

  2. Verify the release installation:

    • List Helm releases:

      helm list

    • Check the Kubernetes resources created:

      kubectl get all -l app.kubernetes.io/name=nginx

Step 3: Customize the Chart

  1. Retrieve the default values for the chart and save them to a file:

    helm show values bitnami/nginx > my-nginx-values.yaml

  2. Open the file “my-nginx-values.yaml” in your favorite text editor.

  3. Make a simple customization. For example, change the number of replicas from 1 to 2 by modifying:

    replicaCount: 1

    to:

    replicaCount: 2

    You can also change other values, such as the service type (e.g., from ClusterIP to LoadBalancer) or image tag.

  4. Save your changes.

Step 4: Upgrade the Release with Your Custom Values

  1. Upgrade the “my-nginx” release using your modified values file:

    helm upgrade my-nginx bitnami/nginx -f my-nginx-values.yaml

  2. Verify the upgrade:

    • Check the status of the release:

      helm status my-nginx

    • Use kubectl to confirm that the number of replicas has increased:

      kubectl get deployment my-nginx

    The Deployment should now show the updated replica count.

Step 5: Roll Back the Release

  1. If you want to revert the changes and go back to the previous version, execute the rollback command:

    helm rollback my-nginx 1

    (The number “1” refers to the previous revision. You can view the revision history with helm history my-nginx.)

  2. Verify that the rollback was successful:

    • Check the release status:

      helm status my-nginx

    • Confirm with kubectl that the Deployment now reflects the previous configuration (e.g., replica count returns to 1).

Step 6: Clean Up

  1. Once you’ve completed the lab, uninstall the release to clean up resources:

    helm uninstall my-nginx

  2. Verify that all related Kubernetes resources are removed:

    kubectl get all -l app.kubernetes.io/name=nginx