Application Load Balancer (ALB) in AWS - Mini Project: Build & Apply

Create an Application Load Balancer (ALB) with Target Group in AWS

📖 Scenario: You are setting up a simple web application on AWS. To distribute incoming web traffic evenly across multiple servers, you need to create an Application Load Balancer (ALB) and connect it to a target group of servers.

🎯 Goal: Build an Application Load Balancer (ALB) with a target group and listener using AWS CloudFormation syntax. This will allow your web traffic to be balanced across your servers.

📋 What You'll Learn

Create a target group named MyTargetGroup listening on port 80 with protocol HTTP

Create an Application Load Balancer named MyALB in public subnets

Create a listener on the ALB for port 80 using HTTP protocol

Attach the listener to the target group MyTargetGroup

💡 Why This Matters

🌍 Real World

Load balancers are essential to distribute web traffic evenly across multiple servers, improving availability and performance.

💼 Career

Cloud architects and DevOps engineers often create and configure load balancers to ensure scalable and reliable web applications.

1

Create the Target Group

Create a resource called MyTargetGroup of type AWS::ElasticLoadBalancingV2::TargetGroup with Port set to 80, Protocol set to HTTP, and VpcId set to vpc-123456.

AWS

# Your code here to create MyTargetGroup resource

Need a hint?

The target group needs a name, port, protocol, and VPC ID.

2

Create the Application Load Balancer

Add a resource called MyALB of type AWS::ElasticLoadBalancingV2::LoadBalancer with Subnets set to ["subnet-111111", "subnet-222222"] and Scheme set to internet-facing.

AWS

Resources:
  MyTargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      Name: MyTargetGroup
      Port: 80
      Protocol: HTTP
      VpcId: vpc-123456

# Your code here to create MyALB resource

Need a hint?

The ALB needs to be internet-facing and placed in public subnets.

3

Create the Listener for the ALB

Add a resource called MyListener of type AWS::ElasticLoadBalancingV2::Listener with LoadBalancerArn referencing MyALB, Port set to 80, Protocol set to HTTP, and DefaultActions forwarding to the target group MyTargetGroup.

AWS

Resources:
  MyTargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      Name: MyTargetGroup
      Port: 80
      Protocol: HTTP
      VpcId: vpc-123456
  MyALB:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Name: MyALB
      Subnets:
        - subnet-111111
        - subnet-222222
      Scheme: internet-facing

# Your code here to create MyListener resource

Need a hint?

The listener connects the ALB to the target group on port 80 using HTTP.

4

Complete the CloudFormation Template

Add the Outputs section with an output named LoadBalancerDNSName that returns the DNS name of MyALB using !GetAtt MyALB.DNSName.

AWS

Resources:
  MyTargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      Name: MyTargetGroup
      Port: 80
      Protocol: HTTP
      VpcId: vpc-123456
  MyALB:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Name: MyALB
      Subnets:
        - subnet-111111
        - subnet-222222
      Scheme: internet-facing
  MyListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      LoadBalancerArn: !Ref MyALB
      Port: 80
      Protocol: HTTP
      DefaultActions:
        - Type: forward
          TargetGroupArn: !Ref MyTargetGroup

# Your code here to add Outputs section

Need a hint?

The output helps you find the ALB's DNS name after deployment.