Helm Chart

Package and deploy a web application using a Helm chart.

Time: ~10 minutes Difficulty: Beginner

What You Will Learn

• Helm chart structure (Chart.yaml, values.yaml, templates/)
• Template functions and helpers
• Overriding values at install time
• Upgrading and rolling back releases

Prerequisites

• Helm v3.13+ installed

Deploy

helm install web-app demos/helm/chart/ \
  --namespace helm-app \
  --create-namespace

Verify

helm list -n helm-app
kubectl get pods -n helm-app
kubectl port-forward svc/web-app-simple-web-app 8080:80 -n helm-app

Open http://localhost:8080 to see nginx running.

What is Happening

chart/
  Chart.yaml              # Chart metadata (name, version)
  values.yaml             # Default configuration values
  templates/
    _helpers.tpl           # Reusable template functions
    deployment.yaml        # Templated Deployment
    service.yaml           # Templated Service

Helm renders the templates by injecting values from values.yaml. The _helpers.tpl file defines common label patterns so you don’t repeat them everywhere.

Experiment

1. Override values at install time:

   helm upgrade web-app demos/helm/chart/ \
     --namespace helm-app \
     --set replicaCount=4 \
     --set env.ENVIRONMENT=staging

2. Check the release history:

   helm history web-app -n helm-app

3. Roll back to the previous revision:

   helm rollback web-app 1 -n helm-app

4. Render templates locally without deploying:

   helm template web-app demos/helm/chart/

Cleanup

helm uninstall web-app -n helm-app
kubectl delete namespace helm-app

Further Reading

See docs/deep-dive.md for a detailed explanation of Go template syntax, helper functions, values override precedence, release lifecycle, and common Helm patterns.

Next Step

Move on to Kustomize to learn environment-specific configuration without templating.