sample-asg.tf

resource "aws_security_group" "instance_sg" {
  name = "Allow ELB access to instance"
  vpc_id = "${aws_vpc.vpc.id}"

  ingress {
    from_port = 8080
    protocol = "tcp"
    to_port = 8080
    security_groups = ["${aws_security_group.elb_sg.id}"]
  }

  egress {
    from_port = 0
    protocol = "-1"
    to_port = 0
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags {
    Name = "${var.team_name}-yocto-instance-sg"
  }
}

resource "aws_security_group" "elb_sg" {
  name = "Allow public access via http"
  vpc_id = "${aws_vpc.vpc.id}"

  ingress {
    from_port = 80
    protocol = "tcp"
    to_port = 80
    cidr_blocks = [
      "0.0.0.0/0"]
  }

  egress {
    from_port = 0
    protocol = "-1"
    to_port = 0
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags {
    Name = "${var.team_name}-yocto-elb-sg"
  }
}

data "template_file" "yocto_userdata" {
  template = "${file("${path.module}/templates/yocto-userdata.tpl")}"
}

resource "aws_launch_configuration" "yocto_lc" {
  name_prefix = "${var.team_name}-"
  image_id = "${var.ami_id}"
  instance_type = "${var.instance_type}"
  key_name = "${var.sshkeyname}"
  user_data = "${data.template_file.yocto_userdata.rendered}"
  security_groups = ["${aws_security_group.instance_sg.id}"]
  associate_public_ip_address = true
  lifecycle { create_before_destroy = true }
}

resource "aws_autoscaling_group" "asg" {
  name_prefix = "${var.team_name}-"
  launch_configuration = "${aws_launch_configuration.yocto_lc.id}"
  max_size = 2
  min_size = 1
  desired_capacity = 1
  vpc_zone_identifier = ["${aws_subnet.public_subnets.*.id}"]
  load_balancers = ["${aws_elb.elb.id}"]
  health_check_type = "ELB"
  health_check_grace_period = 120
  wait_for_capacity_timeout = "3m"

  lifecycle {create_before_destroy = true}

  tags = [
    {
      key = "Name"
      value = "${var.team_name}-yocto"
      propagate_at_launch = true
    }
  ]
}

resource "aws_elb" "elb" {
  name = "${var.team_name}-yocto-elb"
  subnets = ["${aws_subnet.public_subnets.*.id}"]
  security_groups = ["${aws_security_group.elb_sg.id}"]
  listener {
    instance_port = 8080
    instance_protocol = "http"
    lb_port = 80
    lb_protocol = "http"
  }
  health_check {
    healthy_threshold = 2
    interval = 5
    target = "HTTP:8080/status"
    timeout = 2
    unhealthy_threshold = 2
  }
}