Sub Module Prefix Separator Causing Replacements

[joshua-giumelli-deltatre]

Description

The submodules to create the node groups do not have the prefix_seperator variable passed through

The prefix_seperator is not passed through to the submodules (e.g. self-managed-node-group) and all the resources are hardcoded to use - as a separator. This is causing many of our resources to be replaced (ASGs, Launch Templates, etc.) to be replaced as the names/name_prefixes change from using our now non default separator ("") to "-".

ASG source: https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/modules/self-managed-node-group/main.tf#L264

Launch Template source: https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/modules/self-managed-node-group/main.tf#L51

Proposed fix: reuse the prefix_separator variable from the root module in each of the sub modules to replace the - in each resources name_prefix. Similar to the security group from the root module - https://github.com/terraform-aws-modules/terraform-aws-eks/blob/master/main.tf#L111.

This makes our migration to v18.0 extremely difficult as by default all our worker nodes would be replaced.

Example from Terraform Plan:

# module.cluster["0"].module.eks.module.self_managed_node_group["XXXXXXXXXX"].aws_launch_template.this[0] must be replaced
+/- resource "aws_launch_template" "this" {
...
!       name                                 = "XXXXXXXXXXYYYYYYYYYYY" -> (known after apply)
!       name_prefix                          = "XXXXXXXXXX" -> "XXXXXXXXXX-" # forces replacement
...
}

[github-actions]

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