Helm Charts - Interactive Guide

Core Model

What Is Helm?

Package manager for K8s

Helm is to Kubernetes what apt is to Ubuntu or yum is to RHEL — it packages, versions, and distributes application definitions.

Charts

A chart is a directory of templated YAML, a values.yaml with defaults, and a Chart.yaml with metadata (name, version, dependencies).

Releases

Every helm install creates a release — a named, versioned instance of a chart running in a namespace. You can have multiple releases of the same chart.

Repositories

Chart repositories are HTTP servers hosting packaged charts. Public hubs like ArtifactHub aggregate thousands of community charts.

Values override

Override defaults at install time with --set flags or a custom -f values-prod.yaml file — same chart, different environments.

Rollback built-in

Helm tracks every release revision. helm rollback reverts to any previous revision instantly — safer than manually undoing kubectl apply changes.

Helm 3 (current) is a client-only tool — it talks directly to the Kubernetes API server. The server-side Tiller component from Helm 2 is gone.

Chart Structure

Anatomy of a Helm Chart

Directory Layout

mychart/
├── Chart.yaml          # Chart metadata (name, version, appVersion, dependencies)
├── values.yaml         # Default configuration values
├── charts/             # Sub-charts (dependencies)
├── templates/          # Go-template YAML manifests
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── configmap.yaml
│   ├── secret.yaml
│   ├── _helpers.tpl    # Reusable template snippets
│   ├── NOTES.txt       # Post-install usage instructions
│   └── tests/
│       └── test-connection.yaml
├── .helmignore         # Files to exclude from packaging
└── README.md           # Chart documentation

Lifecycle

Helm Release Lifecycle

1

Add Repository

helm repo add bitnami https://charts.bitnami.com/bitnami — register a chart repository locally.

2

Search Charts

helm search repo nginx — find available charts and versions in your added repositories.

3

Inspect Values

helm show values bitnami/nginx — review configurable parameters before installing.

4

Install Release

helm install my-nginx bitnami/nginx -f values-prod.yaml — deploy the chart as a named release.

5

Upgrade Release

helm upgrade my-nginx bitnami/nginx --set replicas=5 — apply config changes or new chart versions.

6

Rollback

helm rollback my-nginx 1 — revert to a previous revision when something breaks.

7

Uninstall

helm uninstall my-nginx — remove the release and all its Kubernetes resources.

Every helm upgrade creates a new revision. Use helm history my-nginx to list all revisions and their statuses.

Setup

Installing Helm on Ubuntu / Linux

Option 1 — Official Install Script (recommended)

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

# Verify
helm version

Option 2 — APT Package Manager (Debian / Ubuntu)

curl https://baltocdn.com/helm/signing.asc | gpg --dearmor | \
  sudo tee /usr/share/keyrings/helm.gpg > /dev/null

echo "deb [arch=$(dpkg --print-architecture) \
  signed-by=/usr/share/keyrings/helm.gpg] \
  https://baltocdn.com/helm/stable/debian/ all main" | \
  sudo tee /etc/apt/sources.list.d/helm-stable-debian.list

sudo apt-get update
sudo apt-get install helm

helm version

Option 3 — Snap

sudo snap install helm --classic
helm version

Option 4 — Download Binary Manually

# Check latest version at https://github.com/helm/helm/releases
HELM_VERSION="v3.16.3"
wget https://get.helm.sh/helm-${HELM_VERSION}-linux-amd64.tar.gz
tar -zxvf helm-${HELM_VERSION}-linux-amd64.tar.gz
sudo mv linux-amd64/helm /usr/local/bin/helm
rm -rf linux-amd64 helm-${HELM_VERSION}-linux-amd64.tar.gz

helm version

macOS (Homebrew)

brew install helm
helm version

Post-Install — Add Popular Repos

# Bitnami (extensive collection of production charts)
helm repo add bitnami https://charts.bitnami.com/bitnami

# Prometheus Community
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

# Ingress-NGINX
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx

# Update local cache
helm repo update

# Verify
helm repo list

Quick Reference

Essential Helm Commands

Category	Command	Description
Repository	`helm repo add NAME URL`	Register a chart repository
	`helm repo update`	Refresh local repo index cache
	`helm repo list`	List added repositories
	`helm repo remove NAME`	Remove a repository
Search	`helm search repo KEYWORD`	Search local repos for charts
	`helm search hub KEYWORD`	Search ArtifactHub
	`helm show values CHART`	Display configurable values
Install / Upgrade	`helm install RELEASE CHART`	Deploy a chart as a new release
	`helm install RELEASE CHART -f values.yaml`	Install with custom values file
	`helm install RELEASE CHART --set key=val`	Install with inline override
	`helm upgrade RELEASE CHART`	Upgrade to new values or chart version
Rollback	`helm rollback RELEASE REVISION`	Revert to a previous revision
Rollback	`helm history RELEASE`	List all release revisions
Status	`helm list`	List installed releases
	`helm status RELEASE`	Show release status and notes
	`helm get values RELEASE`	Show user-supplied values
Debug	`helm template RELEASE CHART`	Render templates locally (no install)
Debug	`helm install --dry-run --debug RELEASE CHART`	Dry run with server-side validation
Cleanup	`helm uninstall RELEASE`	Delete release and its resources
Cleanup	`helm uninstall RELEASE --keep-history`	Delete resources but keep release history
Create / Package	`helm create CHARTNAME`	Scaffold a new chart directory
	`helm package CHARTDIR`	Package chart into .tgz archive
	`helm lint CHARTDIR`	Validate chart for errors
Pull	`helm pull CHART --untar`	Download chart archive and extract

Hands-On

Real-World Helm Examples

Deploy NGINX with Bitnami Chart

# Add repo and install
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update
helm install my-nginx bitnami/nginx --namespace web --create-namespace

# Check release
helm list -n web
kubectl get pods -n web

# Upgrade with custom values
helm upgrade my-nginx bitnami/nginx -n web --set replicaCount=3

# Rollback to revision 1
helm rollback my-nginx 1 -n web

# Cleanup
helm uninstall my-nginx -n web

Install Prometheus Monitoring Stack

helm repo add prometheus-community \
  https://prometheus-community.github.io/helm-charts
helm repo update

# Install with values override file
helm install monitoring prometheus-community/kube-prometheus-stack \
  --namespace monitoring --create-namespace \
  -f monitoring-values.yaml

# View what was deployed
helm status monitoring -n monitoring
kubectl get pods -n monitoring

Custom values.yaml Override

# values-prod.yaml
replicaCount: 5

image:
  repository: myapp
  tag: "2.1.0"

service:
  type: LoadBalancer
  port: 443

resources:
  requests:
    cpu: 250m
    memory: 256Mi
  limits:
    cpu: 500m
    memory: 512Mi

ingress:
  enabled: true
  hosts:
    - host: myapp.example.com
      paths:
        - path: /
          pathType: Prefix

Create Your Own Chart

# Scaffold a new chart
helm create myapp

# Edit templates and values
# templates/deployment.yaml, templates/service.yaml, values.yaml

# Lint for errors
helm lint myapp/

# Test render locally
helm template my-release myapp/

# Package for distribution
helm package myapp/

# Install from local chart
helm install my-release ./myapp

Pull and Inspect a Chart

# Download chart to local directory
helm pull bitnami/nginx --untar

# Explore the chart structure
ls nginx/
cat nginx/Chart.yaml
cat nginx/values.yaml

# Install from local copy with modifications
helm install my-nginx ./nginx -f my-overrides.yaml

Decision Guide

Helm vs Other Deployment Approaches

Aspect	Helm	Kustomize	Plain kubectl apply
Templating	Go templates with conditionals, loops, functions	Overlay patches — no templating	None — raw YAML
Packaging	Versioned .tgz archives, shareable via repos	Directory-based, no packaging	Raw files
Release tracking	Built-in revision history and rollback	None (rely on Git)	None
Dependencies	Chart dependencies in Chart.yaml	Components via bases	Manual ordering
Ecosystem	Thousands of community charts on ArtifactHub	Growing but smaller	N/A
Learning curve	Medium — Go template syntax	Low — patches and overlays	Low — plain YAML
Best fit	Distributing apps, complex multi-resource installs	Environment-specific overlays, GitOps	Simple, one-off deploys

Helm and Kustomize are not mutually exclusive. Many teams use helm template to render charts, then apply Kustomize overlays on top.

Use It Well

Practice and Real-World Thinking

Install from public repo

Add the Bitnami repo, search for WordPress, inspect its values, install it with a custom admin password, then uninstall.

Upgrade and rollback

Install NGINX, upgrade to 5 replicas, verify, then rollback to revision 1. Check helm history output.

Create your own chart

Run helm create, customize the templates for a simple app, lint, template-render locally, then install.

Multi-environment values

Write values-dev.yaml and values-prod.yaml for the same chart — different replica counts, resource limits, and image tags.

Namespace isolation

Install the same chart twice in different namespaces (--namespace staging vs --namespace production) and observe independent releases.

Dry-run debugging

Use helm template and helm install --dry-run --debug to spot rendering issues before deploying anything.