Day 66 - : Building an entire infrastructure through Terraform

Build Your Own AWS Infrastructure with Ease using Infrastructure as Code (IaC) Techniques

Task 1: Create a VPC

Create a VPC (Virtual Private Cloud) with CIDR block 10.0.0.0/16

Create a vpc.tf file and mention the required CIDR block with the name tag of VPC.

resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"

  tags = {
    Name = "main"
  }
}

In this Terraform code:

resource "aws_vpc" "main" - defines an AWS VPC resource named "main."
cidr_block = "10.0.0.0/16" specifies the IP address range for the VPC, allowing you to create instances with IP addresses in the range from 10.0.0.0 to 10.0.255.255.
tags = { Name = "main" } sets a tag for the VPC, giving it the name "main" for easy identification and organization within your AWS account.

Now lets run terraform command . First we run terraform init and then terraform apply as

Task 2: Create a private subnet

Create a private subnet with CIDR block 10.0.1.0/24 in the above VPC.
1. Create a subnet.tf file to define the private subnet with the required configuration tag.

    resource "aws_subnet" "public_subnet" {
      vpc_id     = aws_vpc.main.id
      cidr_block = "10.0.2.0/24"

      tags = {
        Name = "public_subnet"
      }
    }

In this Terraform code:

resource "aws_subnet" "public_subnet" defines an AWS subnet resource named "public_subnet" that will be created within the previously defined VPC.*
vpc_id = aws_vpc.main.id specifies the VPC in which this subnet will be created by referencing the ID of the "aws_vpc.main" resource.
cidr_block = "10.0.2.0/24" sets the CIDR block for the subnet's IP address range, allowing instances within this subnet to have IP addresses in the range from 10.0.2.0 to 10.0.2.255.
tags = { Name = "public_subnet" } defines tags for the subnet resource, with a "Name" tag set to "public_subnet" to identify the purpose of this subnet.

Task 3: Create a public subnet

Create a public subnet with CIDR block 10.0.2.0/24 in the above VPC.
1. Similarly, in the subnet.tf file that we created above define the public subnet block.

Task 4: Create an Internet Gateway

Create an Internet Gateway (IGW) and attach it to the VPC.

Create a internetgateway.tf file and define the internet gateway with the required configurations to attach it to VPC

resource "aws_internet_gateway" "internet_gateway" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "internet_gateway_devops"
  }
}

Task 5: Create a Route table

Create a route table for the public subnet and associate it with the public subnet. This route table should have a route to the Internet Gateway.

Create a routetable.tf file to define the route table configuration in association with the public subnet.

resource "aws_route_table" "route_table" {
  vpc_id = aws_vpc.main.id

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.internet_gateway.id
  }
  tags = {
    Name = "route_table_devops"
  }
}

resource "aws_route_table_association" "public_subnet_association" {
  subnet_id      = aws_subnet.public_subnet.id
  route_table_id = aws_route_table.route_table.id
}

In this Terraform code:

resource "aws_route_table" "route_table" defines an AWS route table resource named "route_table" within the VPC specified by referencing the ID of the "aws_vpc.main" resource.
Inside the route table resource block, a default route is defined with a cidr_block of "0.0.0.0/0," which represents all IP addresses. This default route is directed to the Internet Gateway identified by gateway_id, which is the ID of the "aws_internet_gateway.internet_gateway" resource.
tags = { Name = "route_table_devops" } defines tags for the route table resource, with a "Name" tag set to "route_table_devops" for identification.
resource "aws_route_table_association" "public_subnet_association" associates the route table with a public subnet by specifying the subnet's ID and the route table's ID. This association ensures that the public subnet uses the defined route table for routing traffic.

Verify the route table in the AWS console.

Task 6: Create a security group

Security group: Allow SSH access and HTTP access from anywhere

  resource "aws_security_group" "web_server" {
    name_prefix = "web-server-sg"
    vpc_id = aws_vpc.main.id
    ingress {
      from_port   = 80
      to_port     = 80
      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"]
  }
  }

Task 7: Create an Elastic IP

Create an Elastic IP and associate it with the EC2 instance.

  resource "aws_eip" "ip" {
    instance = aws_instance.server_terraform.id
    vpc      = true
    tags = {
      Name = "elastic-ip"
    }
  }

Task 8 :Create an EC2 instance

Launch an EC2 instance in the public subnet with the following details:
AMI: ami-0557a15b87f6559cf
Instance type: t2.micro
Open the website URL in a browser to verify that the website is hosted successfully.

 resource "aws_security_group" "web_server" {
   name_prefix = "web-server-sg"
   vpc_id = aws_vpc.main.id
   ingress {
     from_port   = 80
     to_port     = 80
     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"]
 }
 }

 resource "aws_instance" "server_terraform" {
   ami           = "ami-007855ac798b5175e"
   instance_type = "t2.micro"
   key_name      = "instance"
   subnet_id = aws_subnet.public_subnet.id
   security_groups = [
     aws_security_group.web_server.id
   ]

   user_data = <<-EOF
               #!/bin/bash
               sudo apt-get update -y
               sudo apt-get install apache2
               sudo systemctl start apache2
               sudo systemctl enable apache2
               echo "<html><body><h1>Hello IaC Project</h1></body></html>" > /var/www/html/index.html
               sudo systemctl restart apache2
               EOF
     tags = {
         Name = "terraform_server"
     }
 }
 resource "aws_eip" "ip" {
   instance = aws_instance.server_terraform.id
   vpc      = true
   tags = {
     Name = "elastic-ip"
   }
 }