Terraform Demo Snippet

launch_config.tf

resource "aws_launch_configuration" "client" {
  name_prefix   = "${var.client_asg_name}"
  image_id      = "${data.aws_ami.ubuntu.image_id}"
  instance_type = "${var.instance_type}"

  user_data = "${data.template_file.client_user_data.rendered}"

  associate_public_ip_address = false
  security_groups             = ["${aws_security_group.client.id}"]

  root_block_device {
    volume_type           = "gp2"
    volume_size           = "8"
    delete_on_termination = "true"
  }

  # SSH Access
  key_name = "${var.ssh_key}"

  # Important note: whenever using a launch configuration with an auto scaling group, you must set
  # create_before_destroy = true. However, as soon as you set create_before_destroy = true in one resource, you must
  # also set it in every resource that it depends on, or you'll get an error about cyclic dependencies (especially when
  # removing resources). For more info, see:
  #
  # https://www.terraform.io/docs/providers/aws/r/launch_configuration.html
  # https://terraform.io/docs/configuration/resources.html
  lifecycle {
    create_before_destroy = true
  }
}