Day 49: Terraform hands-on project

Hello everyone!

Welcome back to our Terraform journey.

In the previous tasks, we have learned about the basics of Terraform, its configuration file, and creating an EC2 instance using Terraform. Today, we will explore more about Terraform and create multiple resources.

This Terraform hands-on task is designed to test our proficiency in using Terraform for Infrastructure as Code (IaC) on AWS. We will be tasked with creating a VPC, subnets, and an internet gateway, and launching an EC2 instance with a web server running on it. This task will showcase your skills in automating infrastructure deployment using Terraform.

**Tasks

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

Connect to our ec2 instance and add the following code to your Terraform configuration in main.tf file

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

  tags = {
    Name = "main"
  }
}

Our main.tf will look like below

terraform{
 required_providers {
        aws = {
        source = "hashicorp/aws"
        version = "~> 4.16"
                }
  }
        required_version = ">=1.2.0"
}

provider "aws" {
region = "us-east-1"
}

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

  tags = {
    Name = "main"
  }
}

Execute terraform init, plan, apply to build the VPC.

terraform init
terraform plan
terraform apply

Go to VPC console and check new VPC with name ‘main’ is successfully created.

2) Create a public subnet with CIDR block 10.0.1.0/24 in the above VPC.

• Add the following code to your Terraform configuration in main.tf file

resource "aws_subnet" "public_subnet" {
  vpc_id      = aws_vpc.main.id
  cidr_block  = "10.0.1.0/24"
  tags = {
    Name = "Public Subnet"
  }
}

This code creates a public subnet resource named “public_subnet” with the specified CIDR block

3) Create a private subnet with CIDR block 10.0.2.0/24 in the above VPC.

resource “aws_subnet” “private_subnet” {
 vpc_id = aws_vpc.main.id
 cidr_block = “10.0.2.0/24”
 availability_zone = “us-east-1”
 tags = {
  Name = "Private Subnet"
 }
}

This code creates a private subnet resource named “private_subnet” with the specified CIDR block.

Go to the subnet console and check new subnet with the names ‘Private Subnet’ and ‘Public Subnet’ is successfully created.

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

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

  tags = {
    Name = "igw"
  }
}

Execute terraform init, plan, apply to build the VPC.

terraform init
terraform plan
terraform apply

Go to Internet gateways console and check new subnet with name ‘igw’ is successfully created.

5) 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.

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

  route {
    cidr_block  = "0.0.0.0/0"
    gateway_id  = aws_internet_gateway.gw.id
  }

  tags = {
    Name = "route-table"
  }
}

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

Execute terraform init, plan, apply to build the VPC.

terraform init
terraform plan
terraform apply

First create a route table for public subnet.

aws_route_table block creates a new route table in the VPC specified by vpc_id attribute. It also defines a route that sends all traffic with destination CIDR 0.0.0.0/0 to the internet gateway specified by gateway_id attribute. The tags attribute sets a name for the route table for easy identification.

Then associate route table with public subnet.

aws_route_table_association block associates the newly created route table with a public subnet specified by the subnet_id attribute. The route_table_id attribute refers to the ID of the route table created in the previous block.

We can verify the route table in AWS console along with the public subnet which is associated in the subnet association section.

6) Launch an EC2 instance in the public subnet with the following details:
- AMI: ami-0557a15b87f6559cf
- Instance type: t2.micro
- Security group: Allow SSH access from anywhere
- User data: Use a shell script to install Apache and host a simple website

aws_instance block creates a new EC2 instance in the public subnet specified by subnet_id attribute. It uses the Amazon Machine Image (AMI) ID ami-0f8ca728008ff5af4, which is a Ubuntu 18.04 LTS image. The key_name attribute specifies the name of the key pair used to SSH into the instance. The vpc_security_group_ids attribute specifies a list of security groups to attach to the instance, in this case, it refers to the ID of the security group created in the next block.

resource “aws_instance” “web_server” {
 ami = “ami-067d1e60475437da2”
 instance_type = “t2.micro”
 subnet_id = aws_subnet.public_subnet.id
 vpc_security_group_ids = [aws_security_group.ssh_access.id]

Security group: Allow SSH access from anywhere

aws_security_group block creates a new security group that allows inbound traffic on ports 22 (SSH) and 80 (HTTP) from any source (0.0.0.0/0). The name_prefix attribute sets a name prefix for the security group, and the vpc_id attribute specifies the ID of the VPC where the security group will be created.

resource "aws_security_group" "ssh_access" {
   name_prefix = "ssh_access"
   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"]
 }
 }

7) User data: Use a shell script to install Apache and host a simple website

The user_data attribute specifies the script to run when the instance is launched. This script updates the package manager, installs Apache web server, creates a basic HTML file, and restarts Apache.

user_data = <<-EOF
    #!/bin/bash

    # Update the package list
    sudo apt update

    # Install Apache
    sudo apt install -y apache2
    sudo cat <<HTML > /var/www/html/index.html
    <!DOCTYPE html>
    <html><body><h1>Welcome to my website</h1></body></html>
    HTML

    sudo systemctl restart apache2
  EOF

Task 9) Create an Elastic IP and associate it with the EC2 instance.

aws_eip block creates a new Elastic IP address and associates it with the instance created in the first block by specifying the instance ID in the instance attribute. The tags attribute sets a name for the Elastic IP for easy identification.

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

Here is our Today’s Task-10

Combine all the configurations to spin up the EC2 instance.

• Launch an EC2 instance in the public subnet with the following details:

• AMI: ami-0557a15b87f6559cf

• Instance type: t2.micro

• Security group: Allow SSH access from anywhere

• User data: Use a shell script to install Apache and host a simple website

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

resource "aws_security_group" "ssh_access" {
   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" "web_server" {
  ami                    = "ami-067d1e60475437da2"
  instance_type          = "t2.micro"
  subnet_id              = aws_subnet.public_subnet.id
  vpc_security_group_ids = [aws_security_group.ssh_access.id]


 user_data = <<-EOF
    #!/bin/bash

    # Update the package list
    sudo apt update

    # Install Apache
    sudo apt install -y apache2
    sudo cat <<HTML > /var/www/html/index.html
    <!DOCTYPE html>
    <html><body><h1>Welcome to my website</h1></body></html>
    HTML

    sudo systemctl restart apache2
  EOF

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

Execute terraform init, plan, apply to build the VPC.

terraform init
terraform plan
terraform apply

Now, we can see in the AWS console for the new EC2 instance that is created.

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Thanks for reading ;)