Building a Two-Tier Architecture on AWS Using Terraform

Introduction

Modern applications demand a robust and scalable architecture to ensure performance, availability, and efficient management. The Two-Tier Architecture, combined with the power of Amazon Web Services (AWS) and Terraform, offers an ideal solution. In this blog post, I'll guide you through the process of setting up a Two-Tier Architecture on AWS using Terraform, leveraging key services such as Virtual Private Cloud (VPC), Relational Database Service (RDS), and Elastic Compute Cloud (EC2).

Understanding the Two-Tier Architecture

The Two-Tier Architecture separates the presentation and application layers, resulting in better maintainability and scalability. The client tier, responsible for user interface and interaction, communicates with the server tier, handling data storage and business logic. Let's dive into how to implement this architecture using AWS services and Terraform.

                                                                FIG. ARCHITECTURE DIAGRAM

Components and Services

1. Virtual Private Cloud (VPC):

• Create a custom VPC to isolate your application's resources.
• Define public and private subnets within the VPC for separation and security.

1. Elastic Compute Cloud (EC2):

• Launch EC2 instances within the private subnet of the VPC for the server tier.
• Use an Auto Scaling Group to ensure scalability and fault tolerance.

1. Relational Database Service (RDS):

• Deploy an RDS instance within the private subnet to manage your application's data.
• Utilize Multi-AZ deployment for high availability and data redundancy.

Step-by-Step Guide

Configure AWS Credentials:

Set up your AWS credentials for Terraform to access your AWS account.

1. Create VPC and Subnets:

2. Define a VPC along with public and private subnets using Terraform. Public subnets will host the client tier's load balancer, while private subnets will host the server tier's EC2 instances and RDS instance.

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4. Set Up Security Groups:

5. Configure security groups to control incoming and outgoing traffic to your resources. Allow the load balancer to communicate with EC2 instances and the RDS instance.

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7. Deploy RDS Instance:

8. Define an RDS instance configuration, specifying parameters like database engine, instance class, and credentials. Ensure that the RDS instance is placed within the private subnet for security.

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10. Implement EC2 Instances:

11. Create an Auto Scaling Group with launch configurations for EC2 instances. Use user data scripts to bootstrap instances with necessary software and configurations.

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13. Load Balancer Setup:

14. Set up an Elastic Load Balancer in the public subnet to distribute traffic to EC2 instances in the private subnet.

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16. Connecting Client and Server Tiers:

17. Establish the necessary communication between the client tier (load balancer) and the server tier (EC2 instances and RDS instance) through appropriate security group rules.

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Benefits and Considerations

• Scalability: The Auto Scaling Group ensures your application can scale according to traffic fluctuations.

• High Availability: Multi-AZ deployment of RDS and distribution of instances across subnets enhance fault tolerance.

• Security: Proper security group configurations and subnet isolation enhance the security of your architecture.

• Infrastructure as Code: Terraform allows you to define and manage your architecture using code, ensuring consistency and reproducibility.

Terraform

Terraform is an open-source infrastructure as code (IAC) tool developed by HashiCorp. It enables developers and operations teams to define and manage cloud resources, infrastructure, and services using declarative configuration files. With Terraform, you can specify the desired state of your infrastructure, and the tool takes care of provisioning and managing those resources in various cloud providers, such as Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), and more.

Terraform State File

In Terraform, the state file is a critical component that tracks the current state of your infrastructure. It contains information about the resources managed by Terraform, their configuration, relationships, and metadata. The state file serves as the source of truth for Terraform, allowing it to understand the differences between your desired configuration and the actual resources in the cloud provider.

Terraform Commands




1. terraform init:

This command initializes a Terraform configuration in a directory. It downloads and installs the required provider plugins and sets up the backend configuration.




2. terraform plan:

Running this command generates an execution plan that shows what changes Terraform will make to your infrastructure. It compares the desired state in your configuration files with the current state of the resources in the cloud provider.




3. terraform apply:

The apply command executes the planned changes and creates, updates, or deletes resources to match the desired state. It prompts you to confirm the execution plan before making any changes.




4. terraform destroy:

This command destroys the infrastructure managed by Terraform. It removes all resources defined in your configuration files. It's important to use this command with caution, as it irreversibly deletes resources.

Conclusion

The combination of Two-Tier Architecture, AWS services, and Terraform empowers you to build a resilient, scalable, and manageable application architecture. As you embark on this journey, remember to follow best practices, monitor your resources, and continuously optimize your setup for both performance and cost efficiency. With Terraform's capabilities and AWS's services, you're well-equipped to create a modern application architecture that meets the demands of today's dynamic applications.

Reference

https://github.com/Hari-278/Two-Tier-Architecture-on-AWS