Deployed a Three-Tier Application on AWS EKS

Deployed a scalable three-tier architecture (web, application, and database) on the AWS Elastic Kubernetes Service (EKS).  Application components were containerized with Docker, and images were managed in AWS Elastic Container Registry (ECR). The cluster setup was automated with eksctl, IAM roles were configured, and OIDC provider integration ensured secure access control. Kubernetes workloads were deployed using kubectl, and AWS Load Balancer Controller was configured to manage traffic efficiently, ensuring high availability and fault tolerance.

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Project Overview

In a three-tier architecture, the application is logically split into three components:

1. Web Tier: The user-facing layer, responsible for serving frontend components.
2. Application Tier: Manages the business logic and backend services.
3. Database Tier: Manages the data storage and retrieval operations.

Using AWS EKS, this architecture is containerized for scalability, high availability, and automated management.

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Steps for deployment

1. Create and Connect to an EC2 Instance

Start by setting up an EC2 instance that will serve as your control plane for managing the EKS cluster.

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2. Install Required Tools in EC2 Instance

The following tools are installed to facilitate interactions with AWS services and Kubernetes clusters, Install all this on your EC2 Instance

• AWS CLI: For interacting with AWS resources.
• eksctl: Simplifies EKS cluster creation and management.
• Docker: For containerizing application components.
• kubectl: For managing Kubernetes workloads.

  # Install AWS CLI
  curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
  sudo apt install unzip
  unzip awscliv2.zip
  sudo ./aws/install -i /usr/local/aws-cli -b /usr/local/bin --update
  aws configure
  
  # Install eksctl
  curl --silent --location "https://github.com/weaveworks/eksctl/releases/latest/download/eksctl_$(uname -s)_amd64.tar.gz" | tar xz -C /tmp
  sudo mv /tmp/eksctl /usr/local/bin
  eksctl version
  
  # Install Docker
  sudo apt-get update
  sudo apt install docker.io
  docker ps
  sudo chown $USER /var/run/docker.sock
  
  # Install kubectl
  curl -o kubectl https://amazon-eks.s3.us-west-2.amazonaws.com/1.19.6/2021-01-05/bin/linux/amd64/kubectl
  chmod +x ./kubectl
  sudo mv ./kubectl /usr/local/bin
  kubectl version --short --client

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3. Build and Push the Docker Image into Elastic Container Registry (ECR)

Authenticate Docker with your AWS ECR and push the both Frontend and Backend image.

# Authenticate Docker with ECR
aws ecr get-login-password --region <region> | docker login --username AWS --password-stdin <account-id>.dkr.ecr.<region>.amazonaws.com
    
# Build your Docker Image
docker push -t <your App Name?
    
# After the build completes, tag your Image
docker tag <image-name>:latest <account-id>.dkr.ecr.<region>.amazonaws.com/<repo-name>:latest
    
#Push your Image into ECR
docker push <account-id>.dkr.ecr.<region>.amazonaws.com/<repo-name>:latest

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4. Install and Configure Kubernetes(EKS Cluster)

Set up the EKS cluster using eksctl and configure kubectl.

  # Run the following command to setup EKS cluster
  eksctl create cluster --name three-tier-cluster --region us-west-2 --node-type t2.medium --nodes-min 2 --nodes-max 2
  
  #Configure `kubectl` for the Cluster
  aws eks update-kubeconfig --region us-west-2 --name three-tier-cluster
  kubectl get nodes

  #Create namespace
  kubectl create namespace <name-space name>

  # Creating Deployment and Services for frontend and backend
  kubectl apply -f <yaml-file name>
  kubectl get deployment -n <name-space name>
  kubectl get svc -n <name-space name>
  kubectl get pods -n <name-space name>
  
  # For Database Goto Database directory in K8s manifest path and deployment the apps
  cd Database
  kubectl apply -f .
  kubectl get all

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5. Create a Service Account

Create an IAM policy and associate it with a service account for the AWS Load Balancer Controller.

    
  # Below command fetch the iam policy for your ALB
  curl -O https://raw.githubusercontent.com/kubernetes-sigs/aws-load-balancer-controller/v2.5.4/docs/install/iam_policy.json
  
  # This command creates the iam policy in your AWS account from the iam_policy.json file 
  aws iam create-policy \
      --policy-name AWSLoadBalancerControllerIAMPolicy \
      --policy-document file://iam_policy.json
  
  # This command apply the load balancer policy to your eks cluster so that your eks cluster is working with your load balancer according to the policy
  eksctl utils associate-iam-oidc-provider --region <region> --cluster <cluster-name> --approve

  # This command create and attach an service account to your cluster so that your cluster is allowed to work with load balancer service.
  eksctl create iamserviceaccount \
    --cluster=<your-cluster-name> \
    --namespace=<name-space>\
    --name=aws-load-balancer-controller \
    --role-name AmazonEKSLoadBalancerControllerRole \
    --attach-policy-arn=arn:aws:iam::<your-aws-account-id>:policy/AWSLoadBalancerControllerIAMPolicy \
    --region=<your-region> \
    --approve

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6. Setting up Application Load Balancer (ALB) and Ingress controller

Use Helm to deploy the AWS Load Balancer Controller.To access the application we need to configure below,

• We need to configure ALB (Application Load Balancer) to allow external traffic into AWS EKS Cluster.
• Ingress to enable internal routing between all three tiers within the cluster.

    # Deploy the Load Balancer Controller, using Helm. Helm is a package manager for Kubernetes that simplifies deploying and managing applications on a Kubernetes cluster
    sudo snap install helm --classic
    helm repo add eks https://aws.github.io/eks-charts
    helm repo update eks

    # Install the load balancer controller on your eks cluster
    helm install aws-load-balancer-controller eks/aws-load-balancer-controller -n <name-space> --set clusterName=my-cluster --set serviceAccount.create=false --set serviceAccount.name=aws-load-balancer-controller
    kubectl get deployment -n <name-space> aws-load-balancer-controller
    
    # Now setup ingress for internal routing
    kubectl apply -f ingress.yaml
    kubectl get ing -n <name-space>

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