Agnes

Day 66 - Terraform Hands-on Project - Build Your Own AWS Infrastructure with Ease using Infrastructure as Code (IaC) Techniques(Interview Questions)

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Agnes jadhav
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Day 66 - Terraform Hands-on Project - Build Your Own AWS Infrastructure with Ease using Infrastructure as Code (IaC) Techniques(Interview Questions)

Task:

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

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

tags = {
    Name = "main"
  }
}

This will create a new VPC in your AWS account with the specified CIDR block and a name tag of "main".

Go to the VPC console and check new VPC with the name 'main' is successfully created.

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

To create a public subnet with CIDR block 10.0.1.0/24 in the VPC that you created in the previous step, you can use the following Terraform code:

resource "aws_subnet" "public_subnet" {
  vpc_id     = aws_vpc.main.id
  cidr_block = "10.0.1.0/24"

  tags = {
    Name = "Public Subnet"
  }
}

Go to VPC console then go to Subnets.

Check that "Public Subnet" is created successfully.

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

This Terraform code creates a private subnet with CIDR block 10.0.2.0/24 in the VPC with ID aws_vpc.main.id, and tags it with the name "Private Subnet".

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


  tags = {
    Name = "Private Subnet"
  }
}

Go to VPC console then go to Subnets.

Check that "Public Subnet" is created successfully.

4. 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"
  }
}

This Terraform code creates an internet gateway in the VPC with ID aws_vpc.main.id, and tags it with the name "igw".

terraform apply -

Go to VPC then go to Internet gateways

Check new internet gateway is created with the name 'igw'.

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
}

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 the route table with the 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.

In Route tables, new route table is successfully created.

Route table routes with internet gateway.

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

  • AMI

  • Instance type: t2.micro

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-0f8ca728008ff5af4"
  instance_type = "t2.micro"
  key_name      = "terraform-key"
  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   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

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
        sudo apt-get update -y
        sudo apt-get install apache2 -y
        sudo systemctl start apache2
        sudo systemctl enable apache2
        echo "<html><body><h1>Welcome to my website!</h1></body></html>" > /var/www/html/index.html
        sudo systemctl restart apache2
  EOF

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


  tags = {
    Name = "test-eip"
  }
}

Terraform main.tf file for creating EC2 instance in the public subnet.

Run terraform apply to create the EC2 instance in your AWS account

Open the website URL in a browser to verify that the website is hosted successfully.

Happy Learning!

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