What is Infrastructure as Code?

In today's agile-driven industry time and accuracy is the key. It's really hard for a DevOps engineer to keep up pace with the 2 weeks sprint duration. This is where Infrastructure as Code turns out to be a magic wand. There are a lot of tools in today's market but Terraform is the most popular one.

Why Terraform?

✔ Module support to work with the Cloud providers.
✔ Easy to learn and understand.
✔ Better code maintenance.

Let's look at an example where we can create some AWS resources using Terraform.

ec2_module/main.tf

terraform{
    required_version=">0.12"
}
resource "aws_instance" "web_server"{
    ami=var.ami
    instance_type=var.instance_type
    vpc_security_group_ids = [aws_security_group.SG1.id]
    tags={
        Name="Server-1"
    }
}
resource "aws_security_group" "SG1" {
    name = "WebServer-Security-Group"
    ingress {
      cidr_blocks = [ "0.0.0.0/0" ]
      description = "Port for http"
      from_port = 80
      protocol = "TCP"
      to_port = 80
    } 
}

ec2_module/var.tf

variable "ami" { default = "ami-0557a15b87f6559cf"}

variable "instance_type" { default ="t2.micro"}

ec2_module/output.tf

output "ec2_ip_address" {
  value = aws_instance.web_server.public_ip
}

main.tf

rovider "aws"{
    region="us-east-1"
    access_key=var.access_key
    secret_key=var.secret_key
}

module "ec2_modules"{
    source=".//ec2_modules"
}

In the above code, I have used modules for the reuse of code. With the modular approach, each module contains main.tf, variables.tf and outputs.tf . Every time an EC2 instance is required a call to the module is just referenced from the main.tf which is existing in the root. With this, code redundancy can be kept at bay.