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Terraform is a tool to manage infrastructure as code. It enables the provisioning and management of cloud and on-premises resources using a declarative configuration language, making it easier to automate and maintain infrastructure across multiple platforms.

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Basic Commands ​

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Setup an EC2 instance with terraform ​

tf
provider "aws" {
  region = "ap-south-1"
  access_key = "XXXXXXXXXXXXX"
  secret_key = "XXXXXXXXXXXXX"
}

resource "aws_instance" "demo_ec2" {
  ami = "ami-0024b53e5fc2f4fad"
  instance_type = "t2.nano"

  tags = {
    Name = "Terraform EC2"
  }
}

Few things which required troubleshooting were the following:

  • The access keys from the User created from IAM Identity Center were not working for some reason. Hence, created a user from IAM and applied the credentials generated from there.
  • The image of the instance should be present in the region else you will get an error 'instance not found'.
  • The architecture of the instance should support the architecture of the image. One should not be arm64 and the other should not be x86.

Terraform Input Variables ​

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tf
provider "aws" {
  region = "ap-south-1"
  access_key = "xxxxxxxxxxxxxxxx"
  secret_key = "xxxxxxxxxxxxxxxx"
}

resource "aws_instance" "demo_ec2" {
  ami = "ami-0024b53e5fc2f4fad"
  instance_type = var.instance_type
  count = var.instance_count
  associate_public_ip_address = var.enable_public_ip_address
  tags = merge(
  {
    Name = "Terraform EC2"
  },
  var.project_environment
  )
}

resource "aws_iam_user" "example" {
  count = length(var.user_names)
  name = var.user_names[count.index]
}

variable "instance_type" {
  description = "Type of instance"
  type = string
  default = "t2.nano"
}

variable "instance_count" {
  description = "Number of instances"
  type = number
  default =  2
}

variable "enable_public_ip_address" {
  description = "Enable Public IP address"
  type = bool
  default = true
}

variable "user_names" {
  description = "IAM Usernames"
  type = list(string)
  default = ["user1", "user2", "user3"]
}

variable "project_environment" {
  description = "Project Name and Environment"
  type = map(string)
  default = {
    project = "project-alpha"
    environment = "dev"
  }
}

Terraform tfvars ​

variable.tf ​

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terraform.tfvars ​

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multiple terraform.tfvars ​

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variables passing from cmd ​

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Terraform locals ​

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