🧱Configuring Infrastructure with Terraform

📁Terraform Configuration File:

Create a Terraform configuration file to define a resource of AWS EC2 instance.

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "5.43.0"
    }
  }
}
provider "aws" {
  region = "us-east-2"
}
resource "aws_instance" "my_instance"{
    ami = "ami-5f4884535656"
    instance_type = "t2.micro"
}

📁Check state files

Check state files before running plan and apply commands & Use validate command to validate your tf file for errors and provide the Output generated by each commands.

terraform init

terraform validate

📁Adding Provisioner to Configuration file

You can add a provisioner to your configuration file to configure the resource after it is created. For example, to run a shell script on the EC2 instance after creation, you can use the remote-exec provisioner:

resource "aws_instance" "new-instance" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"

    provisioner "remote-exec" {
    inline = [
      "echo 'Hello, World' > hello.txt",
    ]
  }

In this example:

• We're provisioning an AWS EC2 instance with the aws_instance resource block.

• Inside the aws_instance resource block, we're using the provisioner block to specify a remote-exec provisioner. This provisioner executes commands on the created instance remotely via SSH.

• The inline block contains the commands we want to execute on the remote instance after it's created. In this case, it's just creating a hello.txt file with the text "Hello, World".

📜To apply changes

terraform init
terraform apply

📜To destroy resources

terraform destroy

⚙Add lifecycle management configurations

To control the creation, modification, and deletion of the resource and use Terraform commands to apply the changes.These configurations allow you to specify behaviors such as preventing resource deletion or updating in-place.

resource "aws_instance" "new-instance" {
  ami           = "ami-0c55b159cbfafe1f0"
  instance_type = "t2.micro"

  lifecycle {
    create_before_destroy = true
    prevent_destroy = true
  }
}

In this example:

• We've added a lifecycle block inside the aws_instance resource block.

• create_before_destroy is set to true, which means Terraform will create a new instance before destroying the old one during updates.

• prevent_destroy is set to true, which means Terraform will prevent the instance from being destroyed.

Happy Learning :)