How to Deploy VPC & EC2 with Terraform

Click: complete_code_in_github

Introduction to Terraform:

HashiCorp Terraform is an infrastructure as code tool that lets you define both cloud and on-prem resources in human-readable configuration files.

How Terraform works:

Terraform’s primary function is to create, modify, and destroy infrastructure resources to match the desired state described in the Terraform configuration.
Desire state is the code definition.
Current state is the resource when it’s deployed.

What we will do:

We will create a basic VPC and its components.
We will create a security group
We will create an ec2 instance in the VPC.

Prerequisites:

Install Terraform – https://www.terraform.io/
Install AWS CLI – https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html
Install SDK tool: exp – Visual Studio Code
Configure IAM access to AWS: $ aws configure

To Configure authentication to your AWS Console, you need to create an IAM user and use it’s credentials on the CLI.

0 – Configure Provider:

Create a folder for your project & create a file in it called 0-provider.tf
Terraform provider: Link – https://registry.terraform.io/providers/hashicorp/aws/latest/docs


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

}

Configure Variables and tags

There are other ways of passing variables but here we go.
Create 2 files named variables.tf & terraform.tfvars.
We will pass the variables in the variables file.
We will pass the value in the .tfvars file.
Not to confuse you, we will create just one variable and pass it on the tags, you could create more.

variables.tf


variable "project-name" {
    description = "Write the project name as value in the .tfvars file"
}

terraform.tfvars

This filename shouldn’t be change. It’s unique.


project-name = "my-project-name"

Tag Syntax on resources:

Start using this portion on the VPC and other resources below.
We will use the project name variable to tag our resources.


tags = {
    Name = "${var.project-name}-vpc"
}

1 – Configure VPC:

(Optional) Select a specific CIDR Range for your infrastructure with the Mask Calculator.
Subnet Mask Calculator: Link – https://www.site24x7.com/tools/ipv4-subnetcalculator.html
Every resource has a resource name and a given name.
Example: the resource name is aws_vpc then I gave MyVpc.
Create a file in the root folder called 1-vpc.tf


resource "aws_vpc" "MyVpc" {
    cidr_block = "10.1.0.0/16"
    tags = {
        Name = "${var.project-name}-vpc"
    }
}

2 – Create Internet Gateway:

A VPC always needs an internet gateway to access the internet.
We need to create an IGW and link it to the VPC ID dynamically.
Syntax: “resource_name.given_name.id” = aws_vpc.MyVpc.id
Create a file in the root folder and name it 2-internetgw.tf


resource "aws_internet_gateway" "igw" {
    vpc_id = aws_vpc.MyVpc.id
    tags = {
        Name = "${var.project-name}-igw"
    }
}

3 – Configure Subnets:

To create the subnet we need the VPC ID and a CIDR Block.
We need to link the VPC ID dynamically by following the syntax.
Syntax: “resource_name.given_name.id” = aws_vpc.MyVpc.id
Create a file in the root folder and name it 3-subnets.tf


resource "aws_subnet" "public1" {
    vpc_id             = aws_vpc.MyVpc.id
    cidr_block         = "10.1.1.0/24"
    availability_zone = "us-east-1a"
    
    tags = {
        Name = "${var.project-name}-public1"
    }
}
    
resource "aws_subnet" "public2" {
    vpc_id            = aws_vpc.MyVpc.id
    cidr_block        = "10.1.2.0/24"
    availability_zone = "us-east-1b"
    
    tags = {
        Name = "${var.project-name}-public2"
    }
}

4 – Create Route Tables:

Our VPC has an implicit router which must be attached to a subnet.
We need route tables to control where network traffic is directed.
Dynamically link the internet gateway ID and VPC ID to the route.
Create a file in the root folder and name it 4-routetb.tf


resource "aws_route_table" "public_custom_route_table" {
    vpc_id = aws_vpc.MyVpc.id
    
    route {
        cidr_block = "0.0.0.0/0"
        gateway_id = aws_internet_gateway.igw.id
}
    
tags = {
        Name = "${var.project-name}-public-rt"
    }
}

5 – Configure Route Table Association:

Create the route table association.
Dynamically link the Route tb ID & Subnet ID to the association.
Create a file in the root folder and name it 5-rtassociation.tf


resource "aws_route_table_association" "pub1" {
    subnet_id      = aws_subnet.public1.id
    route_table_id = aws_route_table.public_custom_route_table.id
}
    
resource "aws_route_table_association" "pub2" {
    subnet_id      = aws_subnet.public2.id
    route_table_id = aws_route_table.public_custom_route_table.id
}

6 – Create a security group for our instance:

We need a security group to control traffic to our ec2 instance.
Dynamically link the VPC ID to the security group.
We will open port 80 for http and 22 for SSH.
Create a file in the root folder and name it 6-securitygroup.tf


resource "aws_security_group" "MySg" {
    name        = "my-tf-sg"
    description = "Allow HTTP to web server"
    vpc_id      = aws_vpc.MyVpc.id
    
    ingress {
        description = "SSH ingress"
        from_port   = 22
        to_port     = 22
        protocol    = "tcp"
        cidr_blocks = ["0.0.0.0/0"]
    }
    
    ingress {
        description = "HTTP ingress"
        from_port   = 80
        to_port     = 80
        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 – Create a .pem Key Pair:

Login to AWS Console EC2.
Resource on the left side – Click: Key pair.
Click: Create Key pair.
Give name -> select .pem
Create – it will download on your pc.

8 – Create and EC2 Instance in our VPC:

We know an EC2 instance is a virtual server in the Cloud.
We can install our web app by bootstrapping during provisioning.
We can also install our applications after the instance is created.
We will link multiple resources to the ec2 for it to reside in our VPC.
Pick an AMI ID per your template region by login into AWS Console ec2 -> click create instance and copy AMI ID.
Create a file in the root folder and name it 7-ec2instance.tf


resource "aws_instance" "MyServer" {
    ami                         = "ami-0ff8a91507f77f867"
    instance_type               = "t2.micro"
    key_name                    = "your pem key name without .pem on it"
    monitoring                  = true
    subnet_id                   = aws_subnet.public2.id
    vpc_security_group_ids      = [aws_security_group.MySg.id]
    associate_public_ip_address = true
    
    //CODE//
    # for_each = toset(["node-1", "node-2"])
    #    tags = {
    #      Name = "${each.key}-${var.project-name}-ec2"
    #    }
    
    tags = {
        Name = "${var.project-name}-ec2"
    }
}

Add multiple instances:

You may have a request to create multiple instances.
For each argument is used to add more resources.
Add the code snippet below to create multiple instances.
name them differently.


for_each = toset(["node-1", "node-2"])
    tags = {
        Name = "${each.key}-${var.project-name}-ec2"
    }

Terraform CLI Commands:

terraform init = will initialize the directory by installing independencies.
terraform validate = will help validate if your code is well written.
terraform plan -out main.tfplan = will output the entire plan of the resources that will be created after apply.
terraform apply "main.tfplan" = will deploy the resources in your cloud platform.
terraform destroy = will destroy the whole infrastructure.


$ terraform init
$ terraform validate
$ terraform plan
$ terraform apply
$ terraform destroy

How to Deploy VPC & EC2 with Terraform

How to Deploy VPC & EC2 with Terraform

Introduction to Terraform:

How Terraform works:

What we will do:

Prerequisites:

0 – Configure Provider:

Configure Variables and tags

1 – Configure VPC:

2 – Create Internet Gateway:

3 – Configure Subnets:

4 – Create Route Tables:

5 – Configure Route Table Association:

6 – Create a security group for our instance:

7 – Create a .pem Key Pair:

8 – Create and EC2 Instance in our VPC:

Add multiple instances:

Terraform CLI Commands:

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