Helm Demo

This is a Helm demo using Dev Containers. It was created as part of the presentation "An introduction to Helm: A better way to manage your Kubernetes applications" at the Cloud Native Computing Meetup | November 2023

Setup

You can use DevContainer to run everything inside Docker without installing anything. Start the DevContainer either within VS Code or with GitHub Codespaces.

• Use the Dev Containers in VS Code: Reopen in Container command from the Command Palette (F1, Ctrl+Shift+P).
• 

Simple nginx Helm chart

Let's deploy a simple nginx http server for Bitnami.

1. Install with cli

You can also run this with the script ./demo-1.sh

helm install hello-world oci://registry-1.docker.io/bitnamicharts/nginx

test it

kubectl port-forward svc/hello-world-nginx 8000:80

Step-by-step: What happened

Check what we have deployed:

1. Via the web page https://artifacthub.io/packages/helm/bitnami/nginx
2. Locally

   you can also run this with the script ./demo-2.sh

   1. Download and unpack the Helm chart helm pull oci://registry-1.docker.io/bitnamicharts/nginx --untar --untardir out/
   2. Inspect the out folder tree out/ -L 3
3. See how it looks after it is rendered

   you can also run this with the script ./demo-3.sh helm template --output-dir './out' hello-world oci://registry-1.docker.io/bitnamicharts/nginx

4. Release helm install hello-world oci://registry-1.docker.io/bitnamicharts/nginx
5. Check the release

   you can also run this with the script ./demo-4.sh helm ls

2. Upgrade & add parameters

You can also run this with the script ./demo-10.sh

kubectl get po
helm upgrade hello-world oci://registry-1.docker.io/bitnamicharts/nginx --set replicaCount=2
kubectl get po
helm ls
helm rollback hello-world
kubectl get po

2. Install with values from file

helm upgrade hello-world oci://registry-1.docker.io/bitnamicharts/nginx -f hello-world-values.yaml

Show diff

helm plugin install https://github.com/databus23/helm-diff
helm diff upgrade hello-world oci://registry-1.docker.io/bitnamicharts/nginx -f hello-world-values.yaml

Uninstall the chart

helm uninstall hello-world

Use Helmfile

helmfile apply

Helm with Terraform

(Make sure to uninstall the old chart first if you haven't done so already: helm uninstall hello-world)

terraform init
terraform apply

Create an own chart

1. The creation of a chart has already been completed; you can achieve this by using helm create mychart
2. helm install mychart mychart
3. helm ls
4. kubectl get configmap
5. kubectl get configmap mychart-config-map -o yaml