title: concatenate two variables in terraform
body: <p>i'm trying to create a kubernetes cluster from kops using terraform,following code is a part of infrastructure, i'm trying to create the name concatenate with two variables, and i'm getting illegal char error line two, error happens because im trying to define the name with concatenate variables. is it possible in terraform?</p>
  
  <pre><code>resource "aws_autoscaling_group" "master-kubernetes" {
    name                 = "master-"${var.zone}".masters."${var.cluster_name}""
    launch_configuration = "${aws_launch_configuration.master-kubernetes.id}"
    max_size             = 1
    min_size             = 1
    vpc_zone_identifier  = ["${aws_subnet.subnet-kubernetes.id}"]
  </code></pre>