Create_before_destroy=false in aws_launch_config doesn't work

Terraform
1

I am running the latest version of Terraform 0.12.6.

This seems extremely trivial and I am really confused why it isn’t working. I am setting the create_before_destroy=false for the following launch config but it keeps wanting to create before destroy as indicated in the plan shown below (by the fact that is it +/- instead of -/+).
Resource definition:

resource “aws_launch_configuration” “autoscale_launch_config1” {
name_prefix = “autoscale_launcher-${var.deployment_name}”
image_id = var.ami
instance_type = var.instance_type
security_groups = [aws_security_group.security.id]
enable_monitoring = true
user_data = file(var.user_data_file_string)
lifecycle {
create_before_destroy = false
}
}

Terraform plan:

aws_launch_configuration.autoscale_launch_config1 must be replaced

+/- resource “aws_launch_configuration” “autoscale_launch_config1” {
associate_public_ip_address = false
~ ebs_optimized = false → (known after apply)
enable_monitoring = true
~ id = “autoscale_launcher-CRAIG-Terraform-0downtime-BlueGreen20190821213446641200000005” → (known after apply)
image_id = “ami-07669fc90e6e6cc47”
instance_type = “t2.nano”
+ key_name = (known after apply)
~ name = “autoscale_launcher-CRAIG-Terraform-0downtime-BlueGreen20190821213446641200000005” → (known after apply)
name_prefix = “autoscale_launcher-CRAIG-Terraform-0downtime-BlueGreen”
security_groups = [
“sg-0d93fb85982127b52”,
]
~ user_data = “1320dc5063b001e3a33310f4b48be2cd2711a0d6” → “da99307039ff178c1cd0a6b94937b9f6560f05e5” # forces replacement
- vpc_classic_link_security_groups = → null

  + ebs_block_device {
      + delete_on_termination = (known after apply)
      + device_name           = (known after apply)
      + encrypted             = (known after apply)
      + iops                  = (known after apply)
      + no_device             = (known after apply)
      + snapshot_id           = (known after apply)
      + volume_size           = (known after apply)
      + volume_type           = (known after apply)
    }

  + root_block_device {
      + delete_on_termination = (known after apply)
      + iops                  = (known after apply)
      + volume_size           = (known after apply)
      + volume_type           = (known after apply)
    }
}

Any help as to why this isn’t destroying before creating would be greatly appreciated. Again, I feel it is something very obvious I am missing but i just cannot figure out what. Thank you in advance.

EDIT: This aws_launch_config resource is a trigger in several null resources. Not sure if that would affect anything.

2

Maybe this might help?

3

@shantanugadgil
Thanks for your reply. I have already looked through this page in detail, but could not see what my problem is from the information there. Any specific parts you were referring to?

4

Sorry for being cryptic with the link posting. :smile:

I imagined that using name_prefix automatically meant create_before_destroy set to true .

5

@shantanugadgil
Thank for the follow-up. I tried using the name field that I would manually change each time and it still creates it before it destroys it instead…:frowning: