Multi-tier architecture patterns in AWS - Mini Project: Build & Apply

Build a Multi-tier Architecture on AWS

📖 Scenario: You are setting up a simple multi-tier web application on AWS. This application has three layers: a web layer, an application layer, and a database layer. Each layer will be represented by an AWS resource group.We will create the infrastructure step-by-step using AWS CloudFormation syntax in YAML format to define the resources.

🎯 Goal: Create a CloudFormation template that defines a multi-tier architecture with three layers: WebTier, AppTier, and DBTier. Each tier will be represented by an AWS EC2 instance with specific tags to identify the tier.

📋 What You'll Learn

Define three EC2 instances named WebTierInstance, AppTierInstance, and DBTierInstance.

Each instance must have a Tags property with a Key of Tier and a Value matching its tier name.

Use the Amazon Linux 2 AMI ID ami-0c55b159cbfafe1f0 for all instances.

Set the instance type to t2.micro for all instances.

💡 Why This Matters

🌍 Real World

Multi-tier architectures are common in web applications where separation of concerns improves security, scalability, and maintenance. AWS CloudFormation helps automate the deployment of such architectures.

💼 Career

Understanding how to define multi-tier architectures using Infrastructure as Code is a key skill for cloud engineers and architects working with AWS.

1

Create the Web Tier EC2 Instance

Create a resource called WebTierInstance of type AWS::EC2::Instance with the AMI ID ami-0c55b159cbfafe1f0 and instance type t2.micro. Add a tag with Key set to Tier and Value set to WebTier.

AWS

# Define the WebTierInstance resource here
Resources:
  WebTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: WebTier

Need a hint?

Use the Resources section to define the EC2 instance. Remember to add the Tags property with the correct key and value.

2

Add the Application Tier EC2 Instance

Add a resource called AppTierInstance of type AWS::EC2::Instance with the same AMI ID ami-0c55b159cbfafe1f0 and instance type t2.micro. Add a tag with Key set to Tier and Value set to AppTier. Keep the existing WebTierInstance resource unchanged.

AWS

Resources:
  WebTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: WebTier

  # Add AppTierInstance resource below

Need a hint?

Define the AppTierInstance resource similarly to the WebTierInstance, changing only the tag value to AppTier.

3

Add the Database Tier EC2 Instance

Add a resource called DBTierInstance of type AWS::EC2::Instance with the AMI ID ami-0c55b159cbfafe1f0 and instance type t2.micro. Add a tag with Key set to Tier and Value set to DBTier. Keep the existing WebTierInstance and AppTierInstance resources unchanged.

AWS

Resources:
  WebTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: WebTier
  AppTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: AppTier

  # Add DBTierInstance resource below

Need a hint?

Define the DBTierInstance resource similarly to the other instances, with the tag value set to DBTier.

4

Complete the CloudFormation Template

Add the AWSTemplateFormatVersion set to 2010-09-09 at the top of the template. Keep all three EC2 instance resources unchanged.

AWS

# Add AWSTemplateFormatVersion at the top
AWSTemplateFormatVersion: '2010-09-09'

Resources:
  WebTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: WebTier
  AppTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: AppTier
  DBTierInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-0c55b159cbfafe1f0
      InstanceType: t2.micro
      Tags:
        - Key: Tier
          Value: DBTier

Need a hint?

The AWSTemplateFormatVersion should be the very first line in the template.