Plan fails when enabled set to false

[januaryjon]

Describe the Bug

When using this module in an workspace, but setting the enabled flag to false, running a terraform plan for the workspace will result in the following error:

Error: Invalid function argument

on .terraform/modules/memcached_setting_apigw/outputs.tf line 12, in output "security_group_arn":
12:   value       = join("", module.aws_security_group.*.arn)
  module.aws_security_group is object with 4 attributes

Invalid value for "lists" parameter: element 0 is null; cannot concatenate
null values.

Expected Behavior

Terraform plan should run successfully without creating any resources

Steps to Reproduce

Steps to reproduce the behavior:

1. Create an new terraform workspace with aws provider
2. Add this module to the workspace, use one of the following methods for security group configuration:
   • allowed_cidr_blocks
   • allowed_ipv6_cidr_blocks
   • allowed_ipv6_prefix_list_ids
   • allowed_security_groups
3. Disable this module (set enabled=false for this module)

Environment

• Terraform version: v1.1.8
• AWS provider: v4.8.0

[z0rc]

Same issue when create_security_group = false.

[dmytrozhivotovsky]

I think I found a way to fix it:
e1f9f29