key group does not default to null

[JamesCalleja]

Describe the Bug

key group defaults to an empty list and this does not allow conditional use

variable "trusted_key_groups" {
type = list(string)
default = []
description = "A list of key group IDs that CloudFront can use to validate signed URLs or signed cookies."
}

Expected Behavior

should be allowed to pass an empty sting and default to null value

Steps to Reproduce

{ zone_id = "XXXXXXXXXXx"
domain_name = "domain-name.com"
bucket = "XXXXXX.s3.amazonaws.com"
trusted_key_groups = ""
comment = "CloudFront"
},

Screenshots

No response

Environment

No response

Additional Context

to fix please update variables

variable "trusted_key_groups" {
type = list(string)
default = null
description = "A list of key group IDs that CloudFront can use to validate signed URLs or signed cookies."
}

[oycyc]

@JamesCalleja -- Since the default is an empty list (e.g. default = []), if you don't include that variable, it'll create the CloudFront distribution without any trusted key groups.

In your example, like this

{ zone_id = "XXXXXXXXXXx"
domain_name = "domain-name.com"
bucket = "XXXXXX.s3.amazonaws.com"
~trusted_key_groups = ""~
comment = "CloudFront"
},

Or explicitly set it as trusted_key_group = [] instead of an empty string ("").

I was able to create a CloudFront distribution using the module without setting any trusted_key_group value. Or am I missing something here?