Terraform-provider-aws: Force instance replacement on launch configuration change

[hbarcelos]

Terraform Version

0.9.8

Affected Resource(s)

• autoscaling_group
• autoscaling_launch_configuration

Terraform Configuration Files

The relevant parts are here:

resource "aws_autoscaling_group" "web" {
  name_prefix          = "${var.application}--${data.template_file.environment_name.rendered}--"
  launch_configuration = "${aws_launch_configuration.web.id}"
  vpc_zone_identifier  = ["${data.terraform_remote_state.vpc.all_subnet_ids[var.aws_region]}"]

  min_size = "${var.asg_min_size}"
  max_size = "${var.asg_max_size}"

  load_balancers      = ["${aws_elb.web.name}"]
  health_check_type   = "${var.health_check_type}"
  metrics_granularity = "1Minute"

  tag {
    key                 = "Name"
    value               = "${var.application}--${data.template_file.environment_name.rendered}"
    propagate_at_launch = true
  }

  tag {
    key                 = "Terraform"
    value               = true
    propagate_at_launch = true
  }

  lifecycle {
    create_before_destroy = true
  }
}

resource "aws_launch_configuration" "web" {
  name_prefix     = "lc--${var.application}--${data.template_file.environment_name.rendered}--"
  image_id        = "${lookup(data.terraform_remote_state.amis.default_ami_ids, var.aws_region)}"
  instance_type   = "${var.instance_type}"

  iam_instance_profile = "${var.iam_instance_profile_id}"
  security_groups = ["${aws_security_group.instance.id}"]

  associate_public_ip_address = false

  user_data = "${data.template_file.init_instance.rendered}"
  key_name = "${lookup(data.terraform_remote_state.ssh_keys.key_names, data.template_file.environment_name.rendered)}"
  connection = {
    user = "ubuntu"
  }

  lifecycle {
    create_before_destroy = true
  }
}

Expected Behavior

Instances should be replaced after launch configuration change.

Actual Behavior

The instances are not replaced.

Important Factoids

I believe this could be solved using autoscaling lifecycle hooks, but I couldn't find out how.

[hbarcelos]

Any updates here?

[lfpalacios]

Is this feature already available?

[jensbodal]

You can set the name_prefix of your auto-scaling group to include the generated name of your launch_configuration which will force a new auto-scaling group to be created when the launch configuration changes (as its name will change since you are using name_prefix there as well).

resource "aws_autoscaling_group" "web" {
  name_prefix          = "${aws_launch_configuration.web.name}--"

[cosmopetrich]

There's been some discussion around this in the past, such as #1452 and the Google Groups thread linked there.

[github-actions[bot]]

Marking this issue as stale due to inactivity. This helps our maintainers find and focus on the active issues. If this issue receives no comments in the next 30 days it will automatically be closed. Maintainers can also remove the stale label.

If this issue was automatically closed and you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thank you!

[hashibot[bot]]

I'm going to lock this issue because it has been closed for _30 days_ ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. Thanks!