Auto Scaling with ELB integration in AWS - Mini Project: Build & Apply

Auto Scaling with ELB integration

📖 Scenario: You are managing a web application hosted on AWS. To handle varying traffic, you want to automatically add or remove servers. You also want to distribute user requests evenly across these servers using a load balancer.

🎯 Goal: Build an AWS Auto Scaling Group that launches EC2 instances and integrates with an Elastic Load Balancer (ELB) to distribute traffic.

📋 What You'll Learn

Create a launch configuration with a specific AMI and instance type

Create an Elastic Load Balancer (ELB) with a listener on port 80

Create an Auto Scaling Group using the launch configuration and attach it to the ELB

Set the Auto Scaling Group to maintain a minimum and maximum number of instances

💡 Why This Matters

🌍 Real World

Web applications often face changing traffic. Auto Scaling with ELB ensures the app stays responsive and available by adding or removing servers automatically and balancing user requests.

💼 Career

Cloud engineers and DevOps professionals use Auto Scaling and ELB to build scalable, fault-tolerant applications on AWS.

1

Create a Launch Configuration

Create a launch configuration named web-launch-config with the AMI ID ami-0abcdef1234567890 and instance type t2.micro.

AWS

# Your code here to create launch configuration named web-launch-config

Need a hint?

The launch configuration defines the AMI and instance type for your servers.

2

Create an Elastic Load Balancer (ELB)

Create an ELB resource named web-elb with a listener on port 80 for HTTP protocol and attach it to the default VPC subnets.

AWS

resource "aws_launch_configuration" "web_launch_config" {
  name          = "web-launch-config"
  image_id      = "ami-0abcdef1234567890"
  instance_type = "t2.micro"
}

# Your code here to create ELB named web-elb with listener on port 80

Need a hint?

The ELB listens on port 80 and forwards traffic to instances on port 80.

3

Create an Auto Scaling Group

Create an Auto Scaling Group named web-asg using the launch configuration web-launch-config. Attach it to the ELB web-elb and set the minimum size to 1 and maximum size to 3.

AWS

resource "aws_launch_configuration" "web_launch_config" {
  name          = "web-launch-config"
  image_id      = "ami-0abcdef1234567890"
  instance_type = "t2.micro"
}

resource "aws_elb" "web_elb" {
  name               = "web-elb"
  availability_zones = ["us-east-1a", "us-east-1b"]

  listener {
    instance_port     = 80
    instance_protocol = "http"
    lb_port           = 80
    lb_protocol       = "http"
  }
}

# Your code here to create Auto Scaling Group named web-asg

Need a hint?

The Auto Scaling Group uses the launch configuration and attaches to the ELB to balance traffic.

4

Add Health Check Configuration

Add a health check type of ELB and a health check grace period of 300 seconds to the Auto Scaling Group web-asg.

AWS

resource "aws_launch_configuration" "web_launch_config" {
  name          = "web-launch-config"
  image_id      = "ami-0abcdef1234567890"
  instance_type = "t2.micro"
}

resource "aws_elb" "web_elb" {
  name               = "web-elb"
  availability_zones = ["us-east-1a", "us-east-1b"]

  listener {
    instance_port     = 80
    instance_protocol = "http"
    lb_port           = 80
    lb_protocol       = "http"
  }
}

resource "aws_autoscaling_group" "web_asg" {
  name                      = "web-asg"
  launch_configuration      = aws_launch_configuration.web_launch_config.name
  min_size                  = 1
  max_size                  = 3
  availability_zones        = ["us-east-1a", "us-east-1b"]
  load_balancers            = [aws_elb.web_elb.name]

  # Your code here to add health check configuration
}

Need a hint?

Health checks help the Auto Scaling Group know when to replace unhealthy instances.