In this project, we are going to setup the following using Terraform,
VPC
Public subnet
Internet gateway
Route table
Security group
EC2 instance
Elastic IP
The complete terraform code for this project is available on github
The project folder contains 4 files as represented in the below structure.
simple-ec2-web-server/
├── main.tf
├── providers.tf
├── datasources.tf
└── user-data.tpl
Step 1 : providers .tf
The providers .tf file allows Terraform to connect and interact with AWS Cloud.
terraform {
required_providers {
aws = {
source = "hashicorp/aws"
}
}
}
provider "aws" {
region = "us-east-1"
shared_credentials_files = ["~/.aws/credentials"]
profile = "vscode"
}
Step 2 : datasources .tf
This file is used to provide the latest ec2 instance ami id to the main .tf file.
data "aws_ami" "instance_ami" {
most_recent = true
owners = ["137112412989"]
filter {
name = "name"
values = ["al2023-ami-2023.5.20240722.0-kernel-6.1-x86_64"]
}
}
Step 3 : user-data .tpl
We need to provide user data for the ec2, so that it can download and setup server and display the instance's private ip in the webpage.
#!/bin/bash
# Use this for your user data (script from top to bottom)
# install httpd (Linux 2 version)
yum update -y
yum install -y httpd
systemctl start httpd
systemctl enable httpd
echo "<h1>Hello World from $(hostname -f)</h1>" > /var/www/html/index.html
Step 4 : main .tf
First we need to create a VPC.
resource "aws_vpc" "demo_vpc" {
cidr_block = "10.0.0.0/16"
tags = {
name = "demo-vpc"
}
}
Then create a public subnet inside the VPC
resource "aws_subnet" "pub_sub_1" {
vpc_id = aws_vpc.demo_vpc.id
cidr_block = "10.0.1.0/24"
availability_zone = "us-east-1a"
map_public_ip_on_launch = true
tags = {
name = "public-subnet-1"
}
}
Attach an internet gateway to the vpc
resource "aws_internet_gateway" "demo_internet_gateway" {
vpc_id = aws_vpc.demo_vpc.id
tags = {
Name = "dev-igw"
}
}
Create a public route table for the vpc
resource "aws_route_table" "demo_public_rt" {
vpc_id = aws_vpc.demo_vpc.id
tags = {
Name = "dev-public-rt"
}
}
Add a route in the route table which directs 0.0.0.0/0 traffic to internet gateway
resource "aws_route" "default_route" {
route_table_id = aws_route_table.demo_public_rt.id
destination_cidr_block = "0.0.0.0/0"
gateway_id = aws_internet_gateway.demo_internet_gateway.id
}
Associate the route table to the subnet
resource "aws_route_table_association" "demo_public_assoc" {
subnet_id = aws_subnet.pub_sub_1.id
route_table_id = aws_route_table.demo_public_rt.id
}
Create a security group for the vpc. It should allow inbound HTTP traffic on port 80 and all traffic for outbound.
resource "aws_security_group" "demo_sg" {
name = "dev-sg"
description = "dev security group"
vpc_id = aws_vpc.demo_vpc.id
# Allow only port 80 inbound
ingress {
from_port = 80
to_port = 80
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
# Allow all traffic for outbound
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
}
}
Create an ec2 instance with user data
resource "aws_instance" "demo" {
instance_type = "t2.micro"
ami = data.aws_ami.instance_ami.id
user_data = file("user-data.tpl")
vpc_security_group_ids = [aws_security_group.demo_sg.id]
subnet_id = aws_subnet.pub_sub_1.id
}
Output the public ip of instance in the terminal
output "ec2_public_ip" {
description = "The public IP of the EC2 instance"
value = aws_instance.demo.public_ip
}
Create and define the elastic ip is for use in vpc
resource "aws_eip" "elastic_ip"{
instance = aws_instance.demo.id
domain = "vpc"
}
Associate the elastic ip with the ec2 instance
resource "aws_eip_association" "eip_assoc"{
instance_id = aws_instance.demo.id
allocation_id = aws_eip.elastic_ip.id
}
Output the elastic ip in the terminal (Just for you to know the elastic IP)
output "ec2_eip" {
description = "The Elastic IP of the EC2 instance"
value = aws_eip.elastic_ip.public_ip
}
Step 5 : Result
Now when you access the public IP of the instance OR the elastic IP (both should be the same) from your browser, you'll see similar webpage. (Please note to access the ip in http:// and not https://)
