🟢 EC2 in a Public Subnet

A simple EC2 instance deployed in a public subnet, accessible from the internet via an Internet Gateway. SSH access is allowed using a basic security group.

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

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

resource "aws_subnet" "public" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.0.1.0/24"
  map_public_ip_on_launch = true
}

resource "aws_internet_gateway" "igw" {
  vpc_id = aws_vpc.main.id
}

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

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

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

resource "aws_security_group" "allow_ssh" {
  name        = "allow_ssh"
  description = "Allow SSH"
  vpc_id      = aws_vpc.main.id

  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" "ec2" {
  ami           = "ami-0c55b159cbfafe1f0" # Amazon Linux 2 in us-east-1
  instance_type = "t2.micro"
  subnet_id     = aws_subnet.public.id
  security_groups = [aws_security_group.allow_ssh.name]
  associate_public_ip_address = true
}