Auto Scaling groups in AWS - Mini Project: Build & Apply

Auto Scaling Groups Setup in AWS

📖 Scenario: You are managing a web application hosted on AWS. To handle varying traffic, you want to automatically add or remove servers based on demand. This helps keep the app fast and saves money when traffic is low.

🎯 Goal: Create an AWS Auto Scaling group configuration that launches EC2 instances using a launch template. Set the minimum, maximum, and desired number of instances to control scaling.

📋 What You'll Learn

Create a launch template named MyLaunchTemplate with a specified AMI ID and instance type.

Create an Auto Scaling group named MyAutoScalingGroup using the launch template.

Set the Auto Scaling group minimum size to 1, maximum size to 3, and desired capacity to 2.

Attach the Auto Scaling group to a specified VPC subnet.

💡 Why This Matters

🌍 Real World

Auto Scaling groups help websites and applications handle changing traffic by automatically adjusting the number of servers running.

💼 Career

Cloud engineers and DevOps professionals use Auto Scaling groups to ensure applications are reliable, cost-effective, and responsive to user demand.

1

Create the Launch Template

Create a launch template named MyLaunchTemplate with the AMI ID ami-0abcdef1234567890 and instance type t3.micro.

AWS

# Create a launch template named MyLaunchTemplate
# Your code here

Need a hint?

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

2

Define Auto Scaling Group Basic Settings

Create an Auto Scaling group named MyAutoScalingGroup using the launch template MyLaunchTemplate. Set the minimum size to 1, maximum size to 3, and desired capacity to 2.

AWS

resource "aws_launch_template" "MyLaunchTemplate" {
  name_prefix   = "MyLaunchTemplate"
  image_id      = "ami-0abcdef1234567890"
  instance_type = "t3.micro"
}

# Create Auto Scaling group MyAutoScalingGroup with min=1, max=3, desired=2
# Your code here

Need a hint?

Use the launch template ID and set the size parameters for the Auto Scaling group.

3

Attach Auto Scaling Group to VPC Subnet

Add the subnet ID subnet-12345678 to the Auto Scaling group MyAutoScalingGroup so instances launch in this subnet.

AWS

resource "aws_launch_template" "MyLaunchTemplate" {
  name_prefix   = "MyLaunchTemplate"
  image_id      = "ami-0abcdef1234567890"
  instance_type = "t3.micro"
}

resource "aws_autoscaling_group" "MyAutoScalingGroup" {
  name                      = "MyAutoScalingGroup"
  max_size                  = 3
  min_size                  = 1
  desired_capacity          = 2
  launch_template {
    id      = aws_launch_template.MyLaunchTemplate.id
    version = "$Latest"
  }
  # Add subnet_ids here
  # Your code here
}

Need a hint?

Use the vpc_zone_identifier attribute with a list containing the subnet ID.

4

Enable Health Check Grace Period

Add a health check grace period of 300 seconds to the Auto Scaling group MyAutoScalingGroup to allow instances time to start before health checks.

AWS

resource "aws_launch_template" "MyLaunchTemplate" {
  name_prefix   = "MyLaunchTemplate"
  image_id      = "ami-0abcdef1234567890"
  instance_type = "t3.micro"
}

resource "aws_autoscaling_group" "MyAutoScalingGroup" {
  name                      = "MyAutoScalingGroup"
  max_size                  = 3
  min_size                  = 1
  desired_capacity          = 2
  launch_template {
    id      = aws_launch_template.MyLaunchTemplate.id
    version = "$Latest"
  }
  vpc_zone_identifier = ["subnet-12345678"]
  # Add health_check_grace_period here
  # Your code here
}

Need a hint?

This setting helps avoid false health check failures during instance startup.