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Day 68 - Scaling with Terraform 🚀

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Hemanshu S Mahajan
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Day 68 - Scaling with Terraform 🚀

In our journey to master Terraform, we’ve been gradually building our knowledge and capabilities. Yesterday, we delved into the world of AWS S3 bucket provisioning using Terraform. Today, we’re taking it up a notch by exploring how Terraform empowers us to scale our infrastructure effortlessly. Scaling is a fundamental aspect of managing cloud resources, as it allows us to adapt to the ever-changing demands of our applications. Whether your application experiences surges in traffic or periods of relative quiet, Terraform provides the tools to dynamically adjust your resource allocation.

Understanding Scaling

Before we dive into the technical aspects, let’s grasp the concept of scaling. Scaling involves dynamically adding or removing resources to ensure your application can handle variations in demand effectively. As your application grows, more resources are needed to accommodate increased traffic and workload. Conversely, during periods of reduced demand, you can scale down to save costs and optimize resource utilization.

Terraform streamlines this process through its declarative approach to resource management. You specify the desired number of resources, and Terraform takes care of provisioning or de-provisioning them as required, making scaling a breeze.

Task 1: Create an Auto Scaling Group

One of the key tools for scaling in AWS is the Auto Scaling Group (ASG). ASGs allow for the automatic adjustment of EC2 instances based on your application’s demand. Here’s how you can create an ASG with Terraform:

1. Add the following code to your main.tf file to create an Auto Scaling Group:

resource "aws_launch_configuration" "web_server_as" {
  image_id        = "ami-005f9685cb30f234b"
  instance_type  = "t2.micro"
  security_groups = [aws_security_group.web_server.name] 
 user_data = <<-EOF
              #!/bin/bash
              echo "<html><body><h1>You're doing really Great</h1></body></html>" > index.html
              nohup python -m SimpleHTTPServer 80 &
              EOF
}resource "aws_launch_configuration" "web_server_as" {
  image_id        = "ami-005f9685cb30f234b"
  instance_type  = "t2.micro"
  security_groups = [aws_security_group.web_server.name]

  user_data = <<-EOF
              #!/bin/bash
              echo "<html><body><h1>You're doing really Great</h1></body></html>" > index.html
              nohup python -m SimpleHTTPServer 80 &
              EOF
}

resource "aws_autoscaling_group" "web_server_asg" {
  name                 = "web-server-asg"
  launch_configuration = aws_launch_configuration.web_server_lc.name
  min_size             = 1
  max_size             = 3
  desired_capacity     = 2
  health_check_type    = "EC2"
  load_balancers       = [aws_elb.web_server_lb.name]
  vpc_zone_identifier  = [aws_subnet.public_subnet_1a.id, aws_subnet.public_subnet_1b.id]
}2. Run terraform apply to create the Auto Scaling Group.

Task 2: Test Scaling

To test your scaling setup, follow these steps:

1. Navigate to the AWS Management Console and select the Auto Scaling Groups service.

2. Locate and select the Auto Scaling Group (“web-server-asg”) you just created, then click the “Edit” button.

3. Increase the “Desired Capacity” to 3 and click “Save.”

4. Wait a few minutes for the new instances to be launched and become operational.

5. Go to the EC2 Instances service and verify that the new instances have been successfully launched and are running.

6. Decrease the “Desired Capacity” to 1 and wait a few minutes for the extra instances to be terminated.

7. Again, go to the EC2 Instances service and confirm that the surplus instances have been terminated.

Congratulations! You’ve successfully created and tested an Auto Scaling Group using Terraform. This exercise illustrates how Terraform simplifies the process of scaling your infrastructure in response to changing demands.

In summary, Terraform’s ability to manage infrastructure at scale is invaluable in modern cloud environments. It provides a structured and automated approach to resource provisioning, ensuring that your infrastructure evolves seamlessly with the evolving needs of your applications. So, whether it’s a sudden spike in traffic or a lull in activity, Terraform has your scaling needs covered, making it a must-have tool in the arsenal of any cloud engineer or DevOps practitioner. Keep exploring and mastering Terraform to unlock even more possibilities in infrastructure management! 🚀

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