🌐 Three-Tier Application Deployment on AWS EKS

A comprehensive guide to deploying a React Frontend, Node.js Backend, and MongoDB database on Amazon EKS using Docker, ECR, Helm, Kubernetes, and the AWS Load Balancer Controller.

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🏗️ Three-Tier Application Architecture

🏗️ Kubernetes Architecture

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📘 Table of Contents

• Overview
• Architecture Flow
• Prerequisites
• Tool Installation
• Cluster Access Setup
• Deployment Chronology
• MongoDB Deployment
• Backend Deployment
• Frontend Deployment
• Ingress / External Access
• Verification
• Cleanup

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🧩 Overview

This project deploys a three-tier cloud-native application on AWS EKS:

Tier	Component	Technology	Description
1️⃣ Presentation	React Frontend	Docker, Kubernetes	Provides UI, runs on port 3000
2️⃣ Application	Node.js Backend API	Docker, Kubernetes	Handles business logic on port 3500
3️⃣ Data	MongoDB	Stateful Kubernetes Deployment	Stores application data
🌐 External Routing	AWS ALB Ingress Controller	ALB	Publishes services publicly

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Special thanks to LondheShubham153 for helping improve this project!

Use these Kubernetes Cheat Sheet for improving the knowledge on Kubernetes and skills needed for this project!

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🔁 Architecture Flow

1. Frontend (React)

• Dockerized and pushed to Amazon ECR
• Deployed using Helm in Kubernetes

2. Backend (Node.js)

• Packaged as Docker image → stored in ECR
• Deployed via Helm with environment variables and MongoDB connection string

3. MongoDB

• Runs as a Kubernetes Deployment + Persistent Volume Claim
• Secured with k8s Secrets

4. Docker

• All components are built and tagged locally
• Images pushed to ECR for deployment

5. ECR (Elastic Container Registry)

• Stores Docker images consumed by Kubernetes

6. Kubernetes Cluster

Handles:

• Rolling updates
• Auto-healing
• Networking
• Scaling
• Pod lifecycle

7. Ingress

• AWS ALB Ingress routes external traffic
• Separate routes for frontend (/) and backend (/api)

8. Load Balancer

• Public ALB endpoint
• Routes traffic to Ingress Controller

9. Users

• Access the application via ALB FQDN or domain name

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📦 Prerequisites

Before deploying, ensure you have:

• An AWS account

• IAM permissions for:

  • EKS
  • ECR
  • IAM Roles
  • ALB Ingress Controller

• Local copies of:

  • backend-chart/
  • frontend-chart/

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🛠️ Tool Installation

1. Install AWS CLI

curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o awscliv2.zip
unzip awscliv2.zip
sudo ./aws/install
aws --version

2. Configure AWS Credentials

aws configure

3. Install kubectl

curl -o kubectl https://s3.us-west-2.amazonaws.com/amazon-eks/1.29/latest/bin/linux/amd64/kubectl
chmod +x kubectl
sudo mv kubectl /usr/local/bin/
kubectl version --client

4. Install Helm

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

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☸️ Cluster Access Setup

aws eks update-kubeconfig --name <CLUSTER_NAME> --region <REGION>
kubectl get nodes

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🚀 Deployment Chronology

Below is the exact sequence used to deploy your application.

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🍃 MongoDB Deployment

Apply your MongoDB manifest:

kubectl apply -f mongo_manifests.yaml
kubectl get pods -n three-tier

This includes:

• Secret
• PersistentVolume
• PersistentVolumeClaim
• Service
• Deployment

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⚙️ Backend Deployment

Fix applied: liveness/readiness probe indentation and path update (/ok)

Deploy with Helm:

helm upgrade backend-release ./backend-chart \
  --namespace three-tier-app \
  --set image.repository="534232118663.dkr.ecr.ap-south-1.amazonaws.com/three-tier-backend-ecr" \
  --set image.tag="latest" \
  --set mongo.serviceName="mongodb-svc.workshop.svc.cluster.local" \
  --set mongo.servicePort=27017

Validate

kubectl get pods -n three-tier-app

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🎨 Frontend Deployment

helm upgrade frontend-release ./frontend-chart \
  --namespace three-tier-app \
  --set image.repository="534232118663.dkr.ecr.ap-south-1.amazonaws.com/three-tier-frontend-ecr" \
  --set image.tag="latest" \
  --set service.port=3000

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🌍 Ingress / External Access

Fix applied:

Converted JSON-style annotations to YAML block style.

Apply Ingress using Helm:

helm upgrade frontend-release ./frontend-chart \
  --namespace three-tier-app \
  --set ingress.enabled=true \
  --set ingress.className="alb" \
  --set ingress.annotations."alb\.ingress\.kubernetes\.io/scheme"=internet-facing \
  --set ingress.annotations."alb\.ingress\.kubernetes\.io/target-type"=ip \
  --set ingress.annotations."alb\.ingress\.kubernetes\.io/listen-ports"='[{"HTTP":80}]' \
  --set ingress.hosts[0].host="frontend.amanpathakdevops.study" \
  --set ingress.hosts[0].paths[0].path="/" \
  --set ingress.hosts[0].paths[0].pathType="Prefix" \
  --set ingress.hosts[0].paths[1].path="/api" \
  --set ingress.hosts[0].paths[1].pathType="Prefix" \
  --set ingress.hosts[0].paths[1].backend.service.name="backend-release-backend-chart" \
  --set ingress.hosts[0].paths[1].backend.service.port.number=3500

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🔍 Verification

Check ALB hostname:

kubectl get ingress -n three-tier-app

When ALB provisioning is complete, add a CNAME record pointing:

frontend.amanpathakdevops.study --> <ALB DNS Name>

Then access your app:

http://frontend.amanpathakdevops.study

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🧹 Cleanup

eksctl delete cluster --name three-tier-cluster --region us-west-2