Session 01 Introduction to Helm

Helm is the package manager for Kubernetes, designed to simplify deployment, configuration, and lifecycle management of Kubernetes applications using reusable packages called charts.

🧰 Helm Is Like APT/YUM for Kubernetes

Platform	Install Method	Example
Linux	`apt install nginx`	Installs NGINX on system
Kubernetes	`helm install nginx`	Installs NGINX in cluster

Helm Architecture

Overview

Helm 3 architecture is simple because the Tiller component used in Helm 2 has been removed.

Helm primarily consists of:

Helm CLI
Helm Charts
Releases
Kubernetes API Server
Helm Repositories

1. Helm CLI

The Helm CLI is the command line interface used by developers and DevOps engineers to interact with Helm.

Example commands:

helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update
helm install my-nginx bitnami/nginx
helm upgrade my-nginx bitnami/nginx
helm uninstall my-nginx

Responsibilities:

Installing applications
Upgrading applications
Rolling back releases
Packaging charts
Managing repositories

2. Helm Charts

A Helm Chart is a package that contains Kubernetes manifests required to run an application.

Typical Helm chart structure:

mychart/
 ├── Chart.yaml
 ├── values.yaml
 ├── templates/
 │    ├── deployment.yaml
 │    ├── service.yaml
 │    └── ingress.yaml
 └── charts/

Important files:

  File          Description
  ------------- -------------------------------
  Chart.yaml    Metadata about the chart
  values.yaml   Default configuration values
  templates/    Kubernetes manifest templates

3. Releases

A Release is a deployed instance of a Helm chart in a Kubernetes cluster.

Example:

helm install my-nginx bitnami/nginx

Here:

Chart → nginx
Release name → my-nginx

Multiple releases can be created from the same chart.

helm install dev-nginx bitnami/nginx
helm install prod-nginx bitnami/nginx

Helm tracks:

Configuration
Version history
Upgrade records

4. Kubernetes API Server

Helm interacts directly with the Kubernetes API server.

Workflow:

User runs a Helm command
Helm renders chart templates
Kubernetes manifests are generated
Helm sends manifests to Kubernetes API
Kubernetes creates cluster resources

Resources created include:

Pods
Services
Deployments
ConfigMaps
Secrets

5. Helm Repositories

Helm repositories store Helm charts.

Example repository:

https://charts.bitnami.com/bitnami

Add repository:

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

Search charts:

helm search repo nginx

Helm Architecture Workflow

User
  │
  │ helm install
  ▼
Helm CLI
  │
  │ renders templates
  ▼
Helm Chart
  │
  │ Kubernetes manifests generated
  ▼
Kubernetes API Server
  │
  ▼
Cluster Resources
(Pods, Services, Deployments)

Helm 2 vs Helm 3

Feature	Helm 2	Helm 3
Server component	Tiller	Removed
Security	Less secure	Improved
Communication	CLI → Tiller → Kubernetes	CLI → Kubernetes API
Complexity	Higher	Simpler

Helm 3 is more secure and easier to manage.

Note As of 2026, Helm 4 has not yet been officially released as a stable production version.
Most production environments still use Helm 3. Helm 4 is currently under development and is expected to introduce improvements in performance, security, and overall maintainability.

Advantages of Helm

Simplifies Kubernetes application deployment
Supports reusable templates
Enables easy upgrades
Supports rollbacks
Integrates well with CI/CD pipelines

⚙️ Prerequisites

Before using Helm, ensure the following:

✅ A working Kubernetes cluster
✅ kubectl configured to access the cluster
✅ Helm CLI installed on your local system

🔧 Install Helm

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

🧩 Verify Helm Installation

helm version

🌐 How Helm Connects to Kubernetes

Helm does not need a server component (like Tiller in v2). It uses:

Your existing kubeconfig file (~/.kube/config)
Communicates directly with Kubernetes API server
Uses standard Kubernetes resources: Deployments, Services, Secrets, etc.
Releases are tracked in your cluster (by default stored as Kubernetes Secrets)

In essence, Helm is just another Kubernetes client, like kubectl, but focused on packages.

🚀 Getting Started: Using Existing Helm Charts

The fastest way to start with Helm is by installing applications using public charts.

1️⃣ Add a Chart Repository

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

2️⃣ Update the Repository Cache

helm repo update

3️⃣ Search for a Chart

helm search repo nginx

Search without adding a repo

helm search hub nginx

Helm searches Artifact Hub, which is the central public registry for Helm charts and other cloud-native packages.

4️⃣ Install a Chart

helm install my-nginx bitnami/nginx

This command installs the nginx chart from the Bitnami repo as a release named my-nginx.

5️⃣ Verify the Installation

helm list
kubectl get all

📦 Helm Chart Anatomy

A Helm chart is a structured directory containing:

mychart/
├── Chart.yaml        # Chart metadata
├── values.yaml       # Default config values
├── templates/        # Kubernetes YAML templates
├── charts/           # Subcharts (optional)
└── README.md         # Documentation (optional)

🛠️ Create a Chart

helm create myapp

🚢 Helm Repositories

Helm repositories host charts and can be added easily:

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

🚀 Helm Releases

A release is a deployed instance of a chart.

Common Release Commands:

# Install
helm install my-nginx bitnami/nginx

# List
helm list

# Upgrade
helm upgrade my-nginx bitnami/nginx

# Roll back
helm rollback my-nginx 1

# Uninstall
helm uninstall my-nginx

🔧 Customizing Installations

Using `--set` (inline):

helm install my-nginx bitnami/nginx \
  --set service.type=NodePort \
  --set replicaCount=2

Using `--values` (file):

helm install my-nginx bitnami/nginx -f custom-values.yaml

Combine both:

helm install my-nginx bitnami/nginx \
  -f base.yaml \
  --set service.type=LoadBalancer

🔍 Preview and Debug Charts

Preview manifests without installing:

helm template my-nginx bitnami/nginx

Dry-run install:

helm install my-nginx bitnami/nginx --dry-run --debug

📥 Get and Customize Chart Values

Show default values:

helm show values bitnami/nginx

Save for customization:

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

Then install with:

helm install my-nginx bitnami/nginx -f custom-values.yaml

📄 Get Values from a Running Release

helm get values my-nginx -n default --all

🧰 Common Helm CLI Reference

# Add repo
helm repo add <name> <url>

# Update repos
helm repo update

# Search
helm search repo <keyword>

# Install
helm install <release-name> <chart>

# Upgrade
helm upgrade <release-name> <chart>

# Rollback
helm rollback <release-name> <revision>

# Uninstall
helm uninstall <release-name>

# Get installed values
helm get values <release-name> -n <namespace> --all

# Show default values
helm show values <chart-name>

✅ Summary

Helm simplifies app deployment on Kubernetes via reusable charts.
Works with your kubeconfig—no need for server-side components.
Helm v3 is modern, secure, and CI/CD-friendly.
Start by using existing charts, then build and customize your own.