Welcome to Day 65 of the #90DaysOfDevOps Challenge! Today, we will explore how to work with Terraform resources, which are essential for provisioning and managing infrastructure. Let's dive in!

Understanding Terraform Resources

A resource in Terraform represents a component of your infrastructure, such as a physical server, a virtual machine, a DNS record, or an S3 bucket. Resources have attributes that define their properties and behaviours, such as the size and location of a virtual machine or the domain name of a DNS record.

When you define a resource in Terraform, you specify the type of resource, a unique name for the resource, and the attributes that define the resource. Terraform uses the resource block to define resources in your Terraform configuration.

Here's an example of a resource block defining an AWS EC2 instance:

resource "aws_instance" "example" {
  ami           = "ami-0c94855ba95c71c99"
  instance_type = "t2.micro"
  key_name      = "my-keypair"

  tags = {
    Name = "example-instance"
  }
}

In this example, we define an AWS EC2 instance resource with the AMI ID, instance type, key pair name, and a tag for identifying the instance. This resource block tells Terraform to create and manage the specified EC2 instance in your infrastructure.

Task 1: Create a Security Group

To allow traffic to your EC2 instance, you need to create a security group. Here's how:

1. Open your main.tf file and add the following code to create a security group:

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "5.8.0"
    }
  }
}

provider "aws" {
  region = "eu-west-2"
}

resource "aws_security_group" "web_server" {
  name_prefix = "web-server-sg"

  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  ingress {
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  egress {
    from_port        = 0
    to_port          = 0
    protocol         = "-1"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }

}

1. Run terraform init to initialize the Terraform project.

   

2. Run terraform plan to see an execution plan of the changes that Terraform will make to your infrastructure

   

3. Run terraform apply to create the security group.

   

4. We can verify the Security Group has been successfully created in our AWS account.

   

Task 2: Create an EC2 Instance

Now, let's provision an EC2 instance using Terraform. Follow these steps:

1. In your main.tf file, add the following code to create an EC2 instance:

    terraform {
      required_providers {
        aws = {
          source = "hashicorp/aws"
          version = "5.8.0"
        }
      }
    }
   
    provider "aws" {
      region = "eu-west-2"
    }
   
    resource "aws_security_group" "web_server" {
      name_prefix = "web-server-sg"
   
      ingress {
        from_port   = 80
        to_port     = 80
        protocol    = "tcp"
        cidr_blocks = ["0.0.0.0/0"]
      }
   
      ingress {
        from_port   = 443
        to_port     = 443
        protocol    = "tcp"
        cidr_blocks = ["0.0.0.0/0"]
      }
   
      ingress {
        from_port   = 22
        to_port     = 22
        protocol    = "tcp"
        cidr_blocks = ["0.0.0.0/0"]
      }
   
      egress {
        from_port        = 0
        to_port          = 0
        protocol         = "-1"
        cidr_blocks      = ["0.0.0.0/0"]
        ipv6_cidr_blocks = ["::/0"]
      }
   
    }
   
    resource "aws_instance" "web_server" {
      ami           = "ami-0eb260c4d5475b901"
      instance_type = "t2.micro"
      key_name      = "devopschallenge-key"
      subnet_id     = "subnet-03ff724100ea66d8a"
      security_groups = [
        aws_security_group.web_server.id
      ]
      associate_public_ip_address = true
   
      user_data = <<-EOF
                    #!/bin/bash
                    sudo apt update
                    sudo apt install -y apache2
                    sudo systemctl start apache2
                    sudo systemctl enable apache2
                    echo "<html><body><h1>Welcome to my website!</h1></body></html>" > /var/www/html/index.html
                    EOF
    }
   

   Note: Replace the ami and key_name values with your own. You can find a list of available AMIs in the AWS documentation.

2. Run terraform plan andterraform apply to create the EC2 instance using the Security Group created above.

   

Task 3: Access Your Website

Now that your EC2 instance is up and running, you can access the website you just hosted on it. Follow these steps:

1. Obtain the public IP address of your EC2 instance either from the Terraform output or the AWS Management Console.

   

2. Open a web browser and enter the public IP address. You should see the message "Welcome to my website!" displayed.

   

Congratulations! You have successfully created a security group, provisioned an EC2 instance, and hosted a website using Terraform. Stay tuned for Day 66 of the #90daysofdevops challenge, where we'll work on a new Terraform Hands-on Project.