Example code that will create an EC2 instance in AWS that you can connect to from your machine

ec2_public_ip.tf

terraform {
  required_providers {
    aws = {
      source = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

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

  # This will tag all resources we create
  # so we can easily find them later to delete.
  default_tags {
    tags = {
      Terraform = "true"
    }
  }
}

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

  # If you set the `Name` tag, AWS will use it
  # for adding a name to your resource in the console view.
  # This works for some resources but not others.
  tags = {
    Name = "terraform"
  }
}

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

data "aws_ami" "ubuntu" {
  most_recent = true

  filter {
    name   = "name"
    values = ["ubuntu/images/hvm-ssd/ubuntu-jammy-22.04-amd64-server-*"]
  }

  filter {
    name   = "virtualization-type"
    values = ["hvm"]
  }

  owners = ["099720109477"] # Canonical
}

resource "aws_instance" "web" {
  ami           = data.aws_ami.ubuntu.id
  instance_type = "t3.micro"

  # assign it a public ip so we can connect to it
  associate_public_ip_address = true

  # references security group created below
  vpc_security_group_ids = [aws_security_group.sg.id]

  lifecycle {
    replace_triggered_by = [aws_security_group.sg]
  }

  # subnet to launch the instance in
  subnet_id = aws_subnet.public.id

  # simple server running on port 80 so we can verify
  # that the instance is up and we can connect to it
  user_data = <<-EOF
              #!/bin/bash
              echo "Hello, World" > index.html
              nohup busybox httpd -f -p "80" &
              EOF
}

resource "aws_security_group" "sg" {
  name = "terraform"

  # We need to explicitly put the security group in this VPC
  vpc_id = aws_vpc.main.id

  # Inbound HTTP from anywhere
  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

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

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

output "public-ip" {
  value = aws_instance.web.public_ip
}

# Optional, print the URL for convenience
output "url" {
  value = "http://${aws_instance.web.public_ip}"
}