This content originally appeared on DEV Community and was authored by Mohana Priya
Intoduction:
In today's fast-paced tech world, infrastructure as code (IaC) has become essential for managing and automating your cloud resources. Recently, I had the opportunity to dive into Terraform, an open-source IaC tool that allows you to define and provision your infrastructure using a simple, declarative programming language. In this blog, I'll walk you through my journey of building, changing, and deploying infrastructure, as well as querying data outputs using Terraform.
Pre-requisites:
Before we dive into the steps, let's ensure you have the following prerequisites in place:
- AWS Account: If you don't have one, sign up for an AWS account.
- Terraform Installed: Download and install Terraform from the official website.
- AWS CLI Installed: Install the AWS CLI by following the instructions here.
- AWS Credentials Configured: Configure your AWS CLI with your credentials by running aws configure.
Building the infrastructure
Step-1: Terraform Configuration
Each Terraform configuration must be in its own working directory. Create a directory for your configuration.
mkdir terraform-learning
Change into the directory
cd terraform-learning
Create a file to define your infrastructure.
code main.tf
Open main.tf in your text editor, give the configuration below, and save the file.
terraform {
required_providers {
aws = {
source = "hashicorp/aws"
version = "~> 4.16"
}
}
required_version = ">= 1.2.0"
}
provider "aws" {
region = "us-west-2"
}
resource "aws_instance" "My_app_server" {
ami = "ami-830c94e3"
instance_type = "t2.micro"
tags = {
Name = "ExampleInstance"
}
}
Step-2: Initialize the Terraform
Initializing a configuration directory download and installs the providers defined in the configuration, which in this case is the aws provider.
terraform init
Step-3: Create the infrastructure
Apply the configuration now with the terraform apply command.
terraform apply
Enter Yes to apply the cofiguration.
You have now created infrastructure using Terraform! Visit the EC2 console and find your new EC2 instance.
Changing the infrastructure
Step-1: Configuration of new ami
Now update the ami of your instance. Change the aws_instance.My_app_server resource under the provider block in main.tf by replacing the current AMI ID with a new one.
resource "aws_instance" "My_app_server" {
- ami = "ami-830c94e3"
+ ami = "ami-08d70e59c07c61a3a"
instance_type = "t2.micro"
}
Step-2: Apply the changes
After changing the configuration, run terraform apply again to see how Terraform will apply this change to the existing resources.
terraform apply
As included before terraform destroys the existing instance first and the create the new instance in place of it.
Destroy the infrastructure
Once you no longer need infrastructure, you may want to destroy it to reduce your security exposure and costs.
terraform destroy
The terraform destroy command terminates resources managed by your Terraform project.
Defining the Input Variable
Step-1: Set the instance name with variable
Create a new file called variables.tf with a block defining a new instance_name variable.
variable "instance_name" {
description = "Value of the Name tag for the EC2 instance"
type = string
default = "ExampleInstance"
}
Step-2: Update main.tf
In main.tf, update the aws_instance resource block to use the new variable. The instance_name variable block will default to its default value ("ExampleInstance") unless you declare a different value.
resource "aws_instance" "My_app_server" {
ami = "ami-08d70e59c07c61a3a"
instance_type = "t2.micro"
tags = {
- Name = "ExampleInstance"
+ Name = var.instance_name
}
}
Step-3: Apply Configuration
Apply the configuration. Enter yes to confirm the cofiguration.
terraform apply
Step-4: Passing the variable
Now apply the configuration again, this time overriding the default instance name by passing in a variable using the -var flag.
terraform apply -var "instance_name=SecondNameForInstance"
Terraform will update the instance's Name tag with the new name.
Query the Data
Step-1: Output EC2 instance configuration
Create a file called outputs.tf in your learn-terraform-aws-instance directory.
code output.tf
Step-2: Inspect output values
Apply the configuration and enter yes to confirm it.
terraform apply
Step-3: Query Output value
Query the outputs with the terraform output command.
terraform output
Conclusion:
Working with Terraform has been an enlightening experience. Its simplicity and power make managing infrastructure a breeze. Whether you're setting up a static website or managing complex cloud environments, Terraform's declarative approach and extensive provider support have got you covered.
Happy Coding!
This content originally appeared on DEV Community and was authored by Mohana Priya
Mohana Priya | Sciencx (2024-06-27T18:18:30+00:00) Transforming Cloud Infrastructure with Terraform: Build, Change, Deploy. Retrieved from https://www.scien.cx/2024/06/27/transforming-cloud-infrastructure-with-terraform-build-change-deploy/
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