example.tf

terraform {
    required_version = ">= 0.12"
}

provider "aws" {
    region = "eu-west-1"
}

resource "aws_instance" "web" {

    tags = { Subject = "terraform-demo" }

    instance_type = "t2.micro"

    ami = var.aws_amis[var.aws_region]

    subnet_id = aws_subnet.our_subnet.id
}