Hands-On Lab: Helm from Zero to Production

🎯 Lab Objectives

By the end of this lab, you will:

• Create a Helm chart from scratch
  


• Understand every Helm component
  


• Deploy an app using Helm


• Override values per environment


• Perform upgrade and rollback
  


• Troubleshoot Helm like a DevOps engineer

🧰 Prerequisites

You need:

• Kubernetes cluster (Minikube / KIND / EKS)


• kubectl


• Helm v3+

Verify:

kubectl get nodes

helm version

🧠 Lab Architecture (What We Build)

We will deploy a Python Flask app using Helm.

Components:

• Deployment


• Service


• Configurable replicas


• Configurable image


• Helm release management

1️⃣ Install Helm (if not installed)

brew install helm

Verify:

helm version

2️⃣ Create a New Helm Chart

helm create flask-app

This generates:

flask-app/

├── Chart.yaml

├── values.yaml

├── templates/

│   ├── deployment.yaml

│   ├── service.yaml

│   ├── ingress.yaml

│   ├── hpa.yaml

│   ├── serviceaccount.yaml

│   └── _helpers.tpl

3️⃣ Clean the Chart (DevOps Best Practice)

Delete what we don’t need for this lab:

rm -rf flask-app/templates/ingress.yaml

rm -rf flask-app/templates/hpa.yaml

rm -rf flask-app/templates/serviceaccount.yaml

rm -rf flask-app/templates/tests

4️⃣ Understand Chart.yaml

Open:

flask-app/Chart.yaml

Example:

apiVersion: v2

name: flask-app

description: Helm chart for Flask application

type: application

version: 0.1.0

appVersion: "1.0"

🔑 DevOps knowledge

• 
  version → chart version


• 
  appVersion → app version

5️⃣ Configure values.yaml

Edit:

replicaCount: 2



image:

  repository: aisalkyn85/python-todo

  tag: v1

  pullPolicy: IfNotPresent



service:

  type: ClusterIP

  port: 5000

This is where DevOps config lives, not YAML templates.

6️⃣ Understand Helm Templates (Critical)

Open:

templates/deployment.yaml

Key lines:

replicas: {{ .Values.replicaCount }}



image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"

📌 Helm renders this before applying to Kubernetes.

7️⃣ Dry Run (MOST IMPORTANT STEP)

helm install flask ./flask-app --dry-run --debug

You should see:

• Fully rendered Kubernetes YAML


• No resources created

🔥 This is how DevOps prevents outages

8️⃣ Install the Application

helm install flask ./flask-app

Verify:

helm list

kubectl get pods

kubectl get svc

9️⃣ Access the Application

Port-forward:

kubectl port-forward svc/flask-app 5000:5000

Open browser:

http://localhost:5000

🔟 Override Values (Production Pattern)

Create:

values-prod.yaml

replicaCount: 4

image:

  tag: v2

Upgrade:

helm upgrade flask ./flask-app -f values-prod.yaml

Verify:

kubectl get pods

Pods increase → zero downtime

1️⃣1️⃣ Helm Release Management

View release status:

helm status flask

View history:

helm history flask

1️⃣2️⃣ Break It on Purpose (Rollback Lab)

Simulate bad image:

image:

  tag: does-not-exist

Upgrade:

helm upgrade flask ./flask-app -f values-prod.yaml

Pods fail.

1️⃣3️⃣ Rollback (WHY HELM EXISTS)

helm rollback flask 1

Pods recover instantly.

💡 This is the #1 reason Helm is used in production

1️⃣4️⃣ Troubleshooting Like a DevOps Engineer

Helm-level debugging

helm get values flask

helm get manifest flask

helm lint ./flask-app

Kubernetes-level debugging

kubectl describe pod

kubectl logs pod

kubectl get events

📌 Helm installs — Kubernetes runs.

1️⃣5️⃣ Uninstall Cleanly

helm uninstall flask

Everything removed:

• Deployments


• Services


• Release metadata

🧠 What You Just Learned (Critical)

You learned:

• Helm chart structure


• values.yaml vs templates


• Install / upgrade / rollback


• Dry-run debugging


• Real DevOps workflow

🧑‍💻 WHO uses this in real life?

• DevOps Engineers


• Platform Teams


• SREs

Used for:

• Applications


• Monitoring stacks


• Databases


• GitOps pipelines

Production-Grade Microservice Platform with Helm

This project demonstrates that you understand:

• Helm beyond helm install
  


• Environment separation (dev / stage / prod)


• ConfigMaps & Secrets via Helm


• Ingress + Services


• Rolling upgrades & rollback


• Helm troubleshooting


• How DevOps actually deploy apps

This is exactly what companies expect.

🏗️ Architecture Overview

Application Stack

                    🌐 Ingress

                        |

              ┌─────────┴─────────┐

              |                   |

         frontend (React)     backend (Flask API)

                                      |

                                  PostgreSQL

All components are deployed using Helm.

📁 Repository Structure (VERY IMPORTANT)

This structure alone is interview-level.

helm-microservice-platform/

├── charts/

│   ├── frontend/

│   │   ├── Chart.yaml

│   │   ├── values.yaml

│   │   └── templates/

│   │       ├── deployment.yaml

│   │       ├── service.yaml

│   │       └── ingress.yaml

│   ├── backend/

│   │   ├── Chart.yaml

│   │   ├── values.yaml

│   │   └── templates/

│   │       ├── deployment.yaml

│   │       ├── service.yaml

│   │       ├── configmap.yaml

│   │       └── secret.yaml

│   └── database/

│       ├── Chart.yaml

│       ├── values.yaml

│       └── templates/

│           ├── statefulset.yaml

│           ├── service.yaml

│           └── pvc.yaml

├── environments/

│   ├── dev/

│   │   ├── frontend-values.yaml

│   │   ├── backend-values.yaml

│   │   └── db-values.yaml

│   ├── prod/

│   │   ├── frontend-values.yaml

│   │   ├── backend-values.yaml

│   │   └── db-values.yaml

└── README.md

🔑 Core DevOps Concepts Demonstrated

1️⃣ Helm as an Application Manager

• Each service = separate chart


• Independent upgrades


• Independent rollbacks

2️⃣ Environment Separation (CRITICAL)

Example:

helm upgrade --install backend charts/backend \

  -f environments/prod/backend-values.yaml

Same chart → different behavior → no duplication

3️⃣ ConfigMaps via Helm (Backend)

apiVersion: v1

kind: ConfigMap

metadata:

  name: backend-config

data:

  DB_HOST: {{ .Values.database.host }}

  DB_PORT: "{{ .Values.database.port }}"

Injected into pods:

envFrom:

- configMapRef:

    name: backend-config

4️⃣ Secrets via Helm (Safe Handling)

apiVersion: v1

kind: Secret

metadata:

  name: backend-secret

type: Opaque

stringData:

  DB_PASSWORD: {{ .Values.database.password }}

📌 Explain in interviews:

Helm renders secrets but Kubernetes encrypts them at rest.

5️⃣ Stateful Database via Helm

Database chart uses:

• StatefulSet


• PVC


• Headless Service

This proves you understand:

• Stateful workloads


• Storage


• Helm + databases

6️⃣ Ingress Controlled by Helm

hosts:

  - host: app.prod.example.com

    paths:

      - /

Ingress is:

• Environment-specific


• Configurable


• Versioned

🔄 Deployment Workflow (REAL LIFE)

Initial install (dev)

helm install frontend charts/frontend -f environments/dev/frontend-values.yaml

helm install backend charts/backend -f environments/dev/backend-values.yaml

helm install db charts/database -f environments/dev/db-values.yaml

Upgrade backend only

helm upgrade backend charts/backend -f environments/prod/backend-values.yaml

Rollback broken release

helm rollback backend 2

🔥 This is production-grade behavior

🧪 Failure & Troubleshooting Scenarios (INTERVIEW GOLD)

Scenario 1: Bad image pushed

• Pods CrashLoopBackOff


• Helm upgrade fails


• Rollback restores service instantly

Explain:

Helm protects Kubernetes deployments from bad releases.

Scenario 2: Wrong env variable

helm get manifest backend

kubectl describe pod

Explain:

Always inspect rendered YAML, not templates.

Scenario 3: DB not reachable

• Check ConfigMap


• Check Service DNS


• Check StatefulSet ordering

🧠 What Interviewers LOVE About This Project

You can confidently say:

“I built a multi-service Helm platform with environment separation, database state management, Ingress routing, configuration via values files, and rollback-safe deployments.”

That sentence alone is senior-level.

🧩 Optional Advanced Add-Ons (Next Level)

You can extend this project with:

• Helm + Argo CD
  


• Helm hooks (pre-install DB migration)


• Helm tests


• External Secrets (AWS Secrets Manager)


• CI/CD pipeline deploying Helm


• Helm chart versioning strategy

📚 Why This Project Is “Better”