Simple Steps to Deploy a Three-Tier E-Commerce System on AWS EKS

In today’s digital age, a robust and scalable e-commerce platform is crucial for success. Amazon Web Services (AWS) offers a powerful and versatile environment for deploying such systems, and Kubernetes (specifically, Amazon EKS) provides the orchestration needed to manage the complex components efficiently. This guide provides a comprehensive, step-by-step approach to deploying a three-tier e-commerce application on AWS EKS. We’ll cover everything from infrastructure setup to application deployment and monitoring.

Table of Contents

1. Introduction to Three-Tier Architecture and AWS EKS
   • What is Three-Tier Architecture?
   • Benefits of Using AWS EKS for E-Commerce
2. Planning and Preparation
   • Defining Requirements and Scope
   • Choosing the Right AWS Services
   • Security Considerations
3. Setting Up the AWS Infrastructure
   • Creating an EKS Cluster
   • Configuring Networking (VPC, Subnets, Security Groups)
   • Setting Up IAM Roles and Permissions
   • Configuring kubectl
4. Deploying the Database Tier
   • Choosing a Database (e.g., PostgreSQL, MySQL)
   • Deploying a Database on AWS RDS
   • Configuring Database Security and Access
5. Deploying the Application Tier
   • Containerizing the Application (Using Docker)
   • Pushing Images to Amazon ECR
   • Creating Kubernetes Deployments and Services
   • Configuring Autoscaling
6. Deploying the Presentation Tier
   • Choosing a Web Server (e.g., Nginx, Apache)
   • Containerizing the Web Server
   • Creating Kubernetes Deployments and Services
   • Setting Up Load Balancing (Using AWS ALB)
7. Connecting the Tiers
   • Configuring Service Discovery
   • Setting Up DNS Records
8. Monitoring and Logging
   • Setting Up CloudWatch for Metrics
   • Setting Up CloudWatch Logs for Logging
   • Implementing Alerting
9. Security Best Practices
   • Network Security
   • IAM Best Practices
   • Application Security
10. Scaling and Optimization
    • Horizontal Pod Autoscaling (HPA)
    • Vertical Pod Autoscaling (VPA)
    • Database Optimization
11. Continuous Integration and Continuous Deployment (CI/CD)
    • Setting Up a CI/CD Pipeline (Using AWS CodePipeline or Jenkins)
    • Automating Deployments
12. Cost Optimization
    • Right-Sizing Instances
    • Using Spot Instances
    • Optimizing Storage
13. Troubleshooting Common Issues
    • Connection Issues
    • Deployment Failures
    • Performance Problems
14. Conclusion
    • Summary of Key Steps
    • Future Considerations

1. Introduction to Three-Tier Architecture and AWS EKS

What is Three-Tier Architecture?

Three-tier architecture is a well-established and widely used software architecture pattern that organizes an application into three logical tiers:

1. Presentation Tier (Web Tier): This is the user interface layer, responsible for displaying information to the user and collecting user input. It typically consists of web servers, HTML, CSS, JavaScript, and other technologies that handle user interactions.
2. Application Tier (Logic Tier): This tier processes the user input received from the presentation tier, executes business logic, and interacts with the data tier. It often includes application servers, APIs, and business components written in languages like Java, Python, or Node.js.
3. Data Tier (Database Tier): This tier stores and manages the application’s data. It typically consists of database servers, such as MySQL, PostgreSQL, or Oracle, that handle data storage, retrieval, and manipulation.

This separation of concerns offers several advantages:

• Scalability: Each tier can be scaled independently based on its specific needs.
• Maintainability: Changes to one tier are less likely to affect the other tiers.
• Security: Security measures can be implemented at each tier to protect the application and its data.
• Flexibility: Different technologies can be used for each tier, allowing you to choose the best tools for the job.

Benefits of Using AWS EKS for E-Commerce

Amazon Elastic Kubernetes Service (EKS) is a managed Kubernetes service that makes it easy to run Kubernetes on AWS without needing to install, operate, and maintain your own Kubernetes control plane. Using EKS for your three-tier e-commerce application offers several compelling advantages:

• Simplified Management: EKS handles the complexities of managing the Kubernetes control plane, allowing you to focus on deploying and managing your applications.
• Scalability and High Availability: Kubernetes provides built-in scalability and high availability features, ensuring that your e-commerce application can handle peak loads and remain resilient to failures.
• Cost-Effectiveness: EKS allows you to optimize resource utilization and reduce costs by scaling your application based on demand. You only pay for the worker nodes you provision.
• Integration with AWS Services: EKS integrates seamlessly with other AWS services, such as RDS, S3, ALB, and CloudWatch, providing a comprehensive and integrated platform for your e-commerce application.
• Portability: Kubernetes is an open-source container orchestration platform, allowing you to easily migrate your application between different environments, including on-premises data centers and other cloud providers.
• Automated Rollouts and Rollbacks: Kubernetes deployments allow for easily rolling out updates and rolling back to previous versions if necessary.
• Self-Healing: Kubernetes automatically restarts failed containers and replaces unhealthy nodes, ensuring the continuous availability of your application.

2. Planning and Preparation

Defining Requirements and Scope

Before diving into the deployment process, it’s crucial to clearly define your requirements and scope. This involves identifying the specific features and functionalities of your e-commerce application, as well as the expected traffic volume and performance requirements. Consider the following questions:

• What are the core features of your e-commerce application (e.g., product catalog, shopping cart, checkout, user accounts)?
• What is the expected traffic volume (e.g., number of users, transactions per second)?
• What are the performance requirements (e.g., page load times, response times)?
• What are the security requirements (e.g., data encryption, access control)?
• What is your budget for infrastructure and operations?
• What is the timeline for deployment?
• What are the scaling requirements? Will you need to handle seasonal traffic spikes?
• What data residency requirements do you have?

Answering these questions will help you make informed decisions about the technologies and services you’ll use, as well as the resources you’ll need to allocate.

Choosing the Right AWS Services

AWS offers a wide range of services that can be used to build and deploy a three-tier e-commerce application. Selecting the right services for each tier is crucial for achieving optimal performance, scalability, and cost-effectiveness. Here’s a breakdown of the recommended services for each tier:

• Presentation Tier:
  • Amazon EC2: For hosting web servers and load balancers. While not strictly required with EKS, EC2 can still be used for ALB ingress controllers.
  • Amazon Elastic Load Balancing (ALB): For distributing traffic across multiple web servers.
  • Amazon CloudFront: For caching static content and improving website performance.
  • Amazon S3: For storing static assets, such as images and videos.
• Application Tier:
  • Amazon EKS: For orchestrating containers and managing application deployments.
  • Amazon EC2: For running worker nodes in the EKS cluster.
  • Amazon ECR: For storing container images.
  • Amazon SQS: For asynchronous task processing (e.g., order processing, email sending).
  • Amazon ElastiCache: For caching frequently accessed data and improving application performance. Redis or Memcached can be used.
• Data Tier:
  • Amazon RDS: For managed relational databases (e.g., MySQL, PostgreSQL, MariaDB).
  • Amazon Aurora: For high-performance, MySQL-compatible and PostgreSQL-compatible relational databases.
  • Amazon DynamoDB: For NoSQL databases that require high scalability and availability.

Security Considerations

Security should be a top priority when designing and deploying your e-commerce application. Consider the following security measures:

• Network Security:
  • Use Virtual Private Clouds (VPCs) to isolate your resources.
  • Configure Security Groups to control network traffic between tiers.
  • Use Network ACLs to control traffic at the subnet level.
  • Implement a Web Application Firewall (WAF) to protect against common web attacks.
• IAM Best Practices:
  • Use IAM roles to grant permissions to AWS resources.
  • Follow the principle of least privilege.
  • Enable multi-factor authentication (MFA) for all IAM users.
  • Regularly rotate access keys.
• Application Security:
  • Implement input validation to prevent injection attacks.
  • Use secure coding practices.
  • Regularly scan for vulnerabilities.
  • Encrypt sensitive data at rest and in transit.
  • Implement strong authentication and authorization mechanisms.
  • Protect against Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF) attacks.
• Data Security:
  • Encrypt sensitive data both at rest and in transit using AWS KMS and TLS/SSL certificates, respectively.
  • Regularly backup your database and store backups in a secure location, like Amazon S3 with encryption enabled.
  • Implement data masking or tokenization for sensitive data to protect it from unauthorized access.

3. Setting Up the AWS Infrastructure

Creating an EKS Cluster

The first step is to create an EKS cluster. You can do this using the AWS Management Console, the AWS CLI, or Infrastructure as Code (IaC) tools like Terraform or CloudFormation. Here’s an example using the AWS CLI:

1. Install and configure the AWS CLI.
2. Install eksctl, a command-line tool for creating and managing EKS clusters:

   brew install weaveworks/tap/eksctl
   eksctl version

3. Create a cluster configuration file (cluster.yaml):

   apiVersion: eksctl.cluster.k8s.io/v1alpha5
   kind: ClusterConfig
   
   metadata:
     name: my-ecommerce-cluster
     region: us-west-2
   
   nodeGroups:
     - name: ng-1
       instanceType: t3.medium
       desiredCapacity: 3
       minSize: 1
       maxSize: 5
       amiFamily: AmazonLinux2
   

4. Create the EKS cluster using the eksctl command:

   eksctl create cluster -f cluster.yaml

   This process will take approximately 15-20 minutes.

Alternatively, you can create the cluster using the AWS Management Console by navigating to the EKS service and following the on-screen instructions. Using IaC tools like Terraform is the recommended approach for production environments.

Configuring Networking (VPC, Subnets, Security Groups)

Proper network configuration is essential for ensuring the security and availability of your EKS cluster. eksctl automatically creates a VPC for your cluster by default. However, for more control, you can configure your own VPC. You’ll need to create a VPC with at least two public subnets and two private subnets. The public subnets are used for the NAT gateway and load balancers, while the private subnets are used for the EKS worker nodes.

Steps for creating a VPC with public and private subnets:

1. Create a VPC:
   • Choose a CIDR block for your VPC (e.g., 10.0.0.0/16).
2. Create public subnets:
   • Create two public subnets in different availability zones.
   • Choose CIDR blocks for the subnets (e.g., 10.0.1.0/24, 10.0.2.0/24).
   • Associate a route table with an internet gateway to these subnets.
3. Create private subnets:
   • Create two private subnets in different availability zones.
   • Choose CIDR blocks for the subnets (e.g., 10.0.3.0/24, 10.0.4.0/24).
   • Associate a route table with a NAT gateway to these subnets (so they can access the internet). The NAT gateway resides in a public subnet.
4. Create Security Groups:
   • Create a security group for the EKS control plane that allows inbound traffic from your worker nodes.
   • Create a security group for your worker nodes that allows inbound traffic from the control plane and other worker nodes, as well as outbound traffic to the internet.
   • Create security groups for your database and application tiers, allowing only necessary traffic between them.

Example Security Group Rules:

• EKS Control Plane Security Group:
  • Inbound: Allow traffic from Worker Node Security Group on port 443 (HTTPS).
• Worker Node Security Group:
  • Inbound: Allow traffic from EKS Control Plane Security Group on port 1025-65535.
  • Inbound: Allow traffic from other Worker Nodes on all ports (for pod-to-pod communication).
  • Outbound: Allow all traffic to the internet (0.0.0.0/0). Restrict this if possible.
• Database Security Group:
  • Inbound: Allow traffic from Application Tier Security Group on port 5432 (PostgreSQL) or 3306 (MySQL).
  • Outbound: Allow no traffic to the internet.
• Application Tier Security Group:
  • Inbound: Allow traffic from Load Balancer Security Group on ports 80 and 443.
  • Outbound: Allow traffic to Database Security Group on port 5432 (PostgreSQL) or 3306 (MySQL).
• Load Balancer Security Group:
  • Inbound: Allow traffic from the internet (0.0.0.0/0) on ports 80 and 443.
  • Outbound: Allow traffic to Application Tier Security Group on ports 8080 (or the port your application listens on).

Setting Up IAM Roles and Permissions

IAM roles are essential for granting permissions to your EKS cluster and its components. You’ll need to create the following IAM roles:

• EKS Cluster Role: This role allows the EKS control plane to manage resources on your behalf. eksctl creates this automatically.
• Node Instance Role: This role is assigned to the EC2 instances that make up the worker nodes. It allows the worker nodes to join the EKS cluster and access other AWS services. This role should have the following policies attached:
  • AmazonEKSWorkerNodePolicy
  • AmazonEC2ContainerRegistryReadOnly
  • AmazonEKS_CNI_Policy
• Service Account Roles: These roles are used to grant permissions to specific pods running in your EKS cluster. For example, you might create a service account role that allows a pod to read secrets from AWS Secrets Manager.

Creating an IAM Role:

1. Go to the IAM console.
2. Click on “Roles” and then “Create role”.
3. Select “AWS service” as the trusted entity.
4. Choose “EC2” as the service that will use this role (for Node Instance Role).
5. Attach the required policies.
6. Name the role and create it.

Configuring kubectl

kubectl is the command-line tool used to interact with your Kubernetes cluster. To configure kubectl to connect to your EKS cluster, follow these steps:

1. Install kubectl:

   brew install kubectl
   kubectl version

2. Configure kubectl to use the EKS cluster:

   aws eks update-kubeconfig --name my-ecommerce-cluster --region us-west-2

3. Verify the connection:

   kubectl get nodes

   You should see a list of your worker nodes.

4. Deploying the Database Tier

Choosing a Database (e.g., PostgreSQL, MySQL)

Selecting the right database is a critical decision for your e-commerce application. Popular choices include PostgreSQL and MySQL, both of which offer excellent performance, reliability, and scalability. Other options include Amazon Aurora (MySQL-compatible and PostgreSQL-compatible) and Amazon DynamoDB (for NoSQL workloads).

Consider the following factors when choosing a database:

• Data Model: Relational (SQL) vs. NoSQL.
• Scalability Requirements: How much data will you be storing, and how much traffic will you be handling?
• Performance Requirements: What are the expected response times for database queries?
• Cost: What is the cost of the database instance and storage?
• Existing Skills: Do you have existing expertise with a particular database?

For this example, we’ll use PostgreSQL on Amazon RDS.

Deploying a Database on AWS RDS

Amazon RDS makes it easy to set up, operate, and scale relational databases in the cloud. To deploy a PostgreSQL database on RDS, follow these steps:

1. Go to the RDS console.
2. Click on “Create database”.
3. Choose PostgreSQL as the database engine.
4. Select a database instance size (e.g., db.t3.micro, db.t3.small). Consider your workload when selecting the instance size.
5. Configure the database settings (e.g., database name, username, password). Use a strong password!
6. Configure the network settings (e.g., VPC, subnet group, security group). Place the database in a private subnet and use the database security group created earlier.
7. Configure the backup settings (e.g., backup retention period).
8. Launch the database instance.

Configuring Database Security and Access

It’s crucial to secure your database and control access to it. Follow these best practices:

• Use a strong password for the database user.
• Grant only necessary permissions to the database user.
• Configure the database security group to allow traffic only from the application tier.
• Enable encryption at rest and in transit. RDS provides options for this.
• Regularly back up the database. RDS provides automated backups.

Connecting to the Database:

Once the database is created, you can connect to it from your application tier using the database endpoint and credentials.

5. Deploying the Application Tier

Containerizing the Application (Using Docker)

Containerizing your application with Docker allows you to package it with all its dependencies into a single, portable unit. This ensures that your application runs consistently across different environments.

Steps for containerizing your application:

1. Create a Dockerfile in the root directory of your application.
2. Define the base image (e.g., FROM node:14 for a Node.js application).
3. Copy your application code to the container (e.g., COPY . /app).
4. Install dependencies (e.g., RUN npm install).
5. Define the command to run the application (e.g., CMD ["npm", "start"]).
6. Build the Docker image:

   docker build -t my-ecommerce-app .

7. Test the Docker image locally:

   docker run -p 8080:8080 my-ecommerce-app

Example Dockerfile (Node.js):

FROM node:14

WORKDIR /app

COPY package*.json ./

RUN npm install

COPY . .

EXPOSE 8080

CMD ["npm", "start"]

Pushing Images to Amazon ECR

Amazon Elastic Container Registry (ECR) is a fully managed container registry that makes it easy to store, manage, and deploy Docker images. To push your Docker image to ECR, follow these steps:

1. Create an ECR repository:

   aws ecr create-repository --repository-name my-ecommerce-app --region us-west-2

2. Authenticate Docker to ECR:

   aws ecr get-login-password --region us-west-2 | docker login --username AWS --password-stdin YOUR_AWS_ACCOUNT_ID.dkr.ecr.us-west-2.amazonaws.com

3. Tag the Docker image:

   docker tag my-ecommerce-app:latest YOUR_AWS_ACCOUNT_ID.dkr.ecr.us-west-2.amazonaws.com/my-ecommerce-app:latest

4. Push the Docker image to ECR:

   docker push YOUR_AWS_ACCOUNT_ID.dkr.ecr.us-west-2.amazonaws.com/my-ecommerce-app:latest

Creating Kubernetes Deployments and Services

Kubernetes deployments and services are used to manage and expose your application in the EKS cluster. To create a deployment and service for your application, follow these steps:

1. Create a deployment YAML file (deployment.yaml):

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: my-ecommerce-app
   spec:
     replicas: 3
     selector:
       matchLabels:
         app: my-ecommerce-app
     template:
       metadata:
         labels:
           app: my-ecommerce-app
       spec:
         containers:
           - name: my-ecommerce-app
             image: YOUR_AWS_ACCOUNT_ID.dkr.ecr.us-west-2.amazonaws.com/my-ecommerce-app:latest
             ports:
               - containerPort: 8080
             env:
               - name: DATABASE_URL
                 value: "jdbc:postgresql://YOUR_RDS_ENDPOINT:5432/your_database"
               - name: DATABASE_USER
                 value: "your_username"
               - name: DATABASE_PASSWORD
                 value: "your_password"
   

2. Create a service YAML file (service.yaml):

   apiVersion: v1
   kind: Service
   metadata:
     name: my-ecommerce-app-service
   spec:
     selector:
       app: my-ecommerce-app
     ports:
       - protocol: TCP
         port: 80
         targetPort: 8080
     type: ClusterIP
   

3. Apply the deployment and service:

   kubectl apply -f deployment.yaml
   kubectl apply -f service.yaml

Explanation of Deployment YAML:

• apiVersion: apps/v1: Specifies the API version for deployments.
• kind: Deployment: Defines the resource type as a deployment.
• metadata.name: Specifies the name of the deployment.
• spec.replicas: Specifies the desired number of replicas (pods).
• spec.selector.matchLabels: Specifies the labels used to select the pods managed by the deployment.
• spec.template.metadata.labels: Specifies the labels to apply to the pods.
• spec.template.spec.containers: Defines the container configuration.
  • image: Specifies the Docker image to use.
  • ports.containerPort: Specifies the port the container listens on.
  • env: Defines environment variables to pass to the container. These are critical for connecting to the database.

Explanation of Service YAML:

• apiVersion: v1: Specifies the API version for services.
• kind: Service: Defines the resource type as a service.
• metadata.name: Specifies the name of the service.
• spec.selector: Specifies the labels used to select the pods the service will route traffic to.
• spec.ports: Defines the ports the service will expose.
  • port: The port the service listens on.
  • targetPort: The port the container listens on.
• spec.type: ClusterIP: Specifies the service type as ClusterIP, which means the service is only accessible within the cluster. We will use an Ingress to expose it externally.

Configuring Autoscaling

Horizontal Pod Autoscaling (HPA) automatically scales the number of pods in a deployment based on CPU utilization or other metrics. To configure HPA, follow these steps:

1. Install the metrics server: This is required for HPA to function.

   kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

2. Create an HPA YAML file (hpa.yaml):

   apiVersion: autoscaling/v2beta2
   kind: HorizontalPodAutoscaler
   metadata:
     name: my-ecommerce-app-hpa
   spec:
     scaleTargetRef:
       apiVersion: apps/v1
       kind: Deployment
       name: my-ecommerce-app
     minReplicas: 3
     maxReplicas: 10
     metrics:
       - type: Resource
         resource:
           name: cpu
           target:
             type: Utilization
             averageUtilization: 70
   

3. Apply the HPA:

   kubectl apply -f hpa.yaml

This HPA configuration will automatically scale the number of pods in the my-ecommerce-app deployment between 3 and 10, based on CPU utilization. When the average CPU utilization across all pods exceeds 70%, the HPA will increase the number of pods. When the CPU utilization drops below 70%, the HPA will decrease the number of pods.

6. Deploying the Presentation Tier

Choosing a Web Server (e.g., Nginx, Apache)

The presentation tier typically consists of a web server that handles incoming requests and serves static content. Popular choices include Nginx and Apache, both of which are high-performance and reliable web servers. Nginx is generally preferred for its performance and resource efficiency. For this example, we’ll use Nginx.

Containerizing the Web Server

Similar to the application tier, the web server should also be containerized using Docker. This ensures that the web server runs consistently across different environments.

Steps for containerizing the web server:

1. Create a Dockerfile in the root directory of your web server configuration.
2. Define the base image (e.g., FROM nginx:latest).
3. Copy your web server configuration file (e.g., COPY nginx.conf /etc/nginx/nginx.conf).
4. Copy your static content (e.g., COPY static /usr/share/nginx/html).
5. Expose port 80 (e.g., EXPOSE 80).
6. Build the Docker image:

   docker build -t my-ecommerce-nginx .

7. Test the Docker image locally:

   docker run -p 80:80 my-ecommerce-nginx

Example Dockerfile (Nginx):

FROM nginx:latest

COPY nginx.conf /etc/nginx/nginx.conf
COPY static /usr/share/nginx/html

EXPOSE 80

Creating Kubernetes Deployments and Services

Similar to the application tier, Kubernetes deployments and services are used to manage and expose the web server in the EKS cluster.

1. Create a deployment YAML file (nginx-deployment.yaml):

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: my-ecommerce-nginx
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: my-ecommerce-nginx
     template:
       metadata:
         labels:
           app: my-ecommerce-nginx
       spec:
         containers:
           - name: my-ecommerce-nginx
             image: YOUR_AWS_ACCOUNT_ID.dkr.ecr.us-west-2.amazonaws.com/my-ecommerce-nginx:latest
             ports:
               - containerPort: 80
   

2. Create a service YAML file (nginx-service.yaml):

   apiVersion: v1
   kind: Service
   metadata:
     name: my-ecommerce-nginx-service
   spec:
     selector:
       app: my-ecommerce-nginx
     ports:
       - protocol: TCP
         port: 80
         targetPort: 80
     type: ClusterIP
   

3. Apply the deployment and service:

   kubectl apply -f nginx-deployment.yaml
   kubectl apply -f nginx-service.yaml

Setting Up Load Balancing (Using AWS ALB)

An Application Load Balancer (ALB) is used to distribute traffic to the web servers in the EKS cluster. To set up an ALB, you’ll need to use the AWS Load Balancer Controller. This is Kubernetes controller that automatically provisions ALBs based on Ingress resources.

1. Install the AWS Load Balancer Controller: Follow the instructions on the AWS documentation. This typically involves deploying a pre-built YAML file to your cluster and creating an IAM role for the controller.
2. Create an Ingress YAML file (ingress.yaml):

   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: my-ecommerce-ingress
     annotations:
       kubernetes.io/ingress.class: alb
       alb.ingress.kubernetes.io/scheme: internet-facing
       alb.ingress.kubernetes.io/target-type: ip
   spec:
     rules:
       - http:
           paths:
             - path: /
               pathType: Prefix
               backend:
                 service:
                   name: my-ecommerce-nginx-service
                   port:
                     number: 80
   

3. Apply the Ingress:

   kubectl apply -f ingress.yaml

This Ingress configuration will create an ALB that routes traffic to the my-ecommerce-nginx-service. The alb.ingress.kubernetes.io/scheme: internet-facing annotation tells the controller to create an internet-facing ALB, making your website accessible from the internet.

7. Connecting the Tiers

Configuring Service Discovery

Service discovery allows the different tiers of your application to find and communicate with each other