Helm in a Nutshell

1. What is Helm?

Helm is a package manager for Kubernetes that helps deploy applications as charts.

If you’ve worked with Kubernetes, you know that deploying applications can get complicated quickly.

Why Use Helm?

📦 Simplifies complex deployments
🔄 Manages upgrades & rollbacks easily
📜 Encapsulates Kubernetes YAML files into reusable charts
🚀 Enables application versioning
💾 Supports dependency management

Helm abstracts away Kubernetes YAML complexity, making deployments declarative and modular.

2. Helm vs. Other Deployment Methods

Deployment Method	Pros	Cons
kubectl apply	Simple, direct control	Hard to manage updates
Kustomize	Patch-based, built-in	No dependency management
Helm	Reusable, versioned, templated	Learning curve

Helm is ideal when you need reusability, upgrades, and rollback features.

3. Installing Helm

Step 1: Install Helm CLI

For Linux/macOS:

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

For Windows (via Chocolatey):

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choco install kubernetes-helm

Verify installation:

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helm version

4. Deploying Applications with Helm

Step 1: Add a Helm Repository

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

Step 2: Install an Application (e.g., Nginx)

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helm install my-nginx bitnami/nginx

Step 3: Verify Installation

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kubectl get pods

To uninstall:

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helm uninstall my-nginx

5. Creating a Helm Chart

Helm charts are pre-packaged Kubernetes applications.

Step 1: Create a Chart Structure

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helm create mychart
cd mychart

This generates:

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

Step 2: Define the Chart.yaml

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apiVersion: v2
name: mychart
description: A Helm chart for Kubernetes
type: application
version: 1.0.0
appVersion: 1.16.0

Step 3: Modify values.yaml

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replicaCount: 2

image:
  repository: nginx
  tag: latest

service:
  type: ClusterIP
  port: 80

Step 4: Deploy Your Custom Chart

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helm install myrelease ./mychart

To upgrade:

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helm upgrade myrelease ./mychart

6. Helm Advanced Features

6.1 Managing Dependencies

Define dependencies in Chart.yaml:

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dependencies:
  - name: postgresql
    version: "12.1.0"
    repository: "https://charts.bitnami.com/bitnami"

Then update dependencies:

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helm dependency update

6.2 Using Helm Hooks

Define lifecycle hooks:

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annotations:
  "helm.sh/hook": post-install

This runs the script after installation.

6.3 Rollbacks and Versioning

To list all releases:

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helm list

To rollback:

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helm rollback myrelease 1

7. Helm in Production: Best Practices

✅ Use values.yaml to configure deployments instead of modifying templates directly
✅ Enable Helm’s built-in rollback features for safe deployments
✅ Use Helmfile for managing multiple Helm releases
✅ Regularly update Helm charts and repositories
✅ Store Helm values in Git for version control

Key Takeaways

✅ Helm simplifies Kubernetes application deployment
✅ Helm Charts package YAML files into reusable templates
✅ Helm supports upgrades, rollbacks, and dependencies
✅ Best practices help keep deployments secure and manageable