Default "zone_id" to empty string for "dns" module

[marcuz]

what

• zone_id passed to dns module must be a string

why

• dns module expects zone_id to be type string
• If var.zone_id[0] try function call fails it defaults to [], which terraform complains about:

│ Error: Invalid value for module argument
│ 
│   on .terraform/modules/[REDACTED]/main.tf line 199, in module "dns":
│  199:   zone_id  = try(var.zone_id[0], var.zone_id)
│ 
│ The given value is not suitable for child module variable "zone_id" defined at .terraform/modules/[REDACTED].dns/variables.tf:1,1-19: string required.

I am unsure why it doesn't simply skip this check because of length(var.zone_id) > 0 (which is []). 🤔

My current workaround is setting zone_id = "" in the module resource.

references

• Upgrade to new securty-group standards #133

[nitrocode]

It looks like the change in PR #133 was due to closing #82

The downstream https://github.com/cloudposse/terraform-aws-route53-cluster-hostname#input_zone_id requires a string and in this module, zone_id is using type any.

The issue with your PR is that it will skip inserting the var.zone_id unless it's a list.

cc: @Nuru , Could we simply change the variable default to null to get around this ?

or we could upgrade the https://github.com/cloudposse/terraform-aws-route53-cluster-hostname to take an input of a list

[Nuru]

@nitrocode Fixing route53-cluster-hostname to take a list is the right long-term solution, but we don't need to wait for that.