fix(acm): cannot use null in length due to optional block variables

Set default value of optional attributes to `null`.

Author: saumitra-dev

modules/acm/README.md

@@ -29,9 +29,9 @@ No modules.
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| <a name="input_amazon_issued_certificates"></a> [amazon\_issued\_certificates](#input\_amazon\_issued\_certificates) | List of Amazon-issued certificates to ACM create | <pre>map(object({<br>    domain_name               = string<br>    subject_alternative_names = optional(list(string), [])<br>    validation_method         = optional(string)<br>    key_algorithm             = optional(string)<br>    options = optional(object({<br>      certificate_transparency_logging_preference = optional(string)<br>    }))<br>    validation_option = optional(object({<br>      domain_name       = string<br>      validation_domain = string<br>    }))<br>    tags = optional(map(any), {})<br>  }))</pre> | `{}` | no |
-| <a name="input_imported_certificates"></a> [imported\_certificates](#input\_imported\_certificates) | List of imported certificates to use to create ACM certificates | <pre>map(object({<br>    private_key       = string<br>    certificate_body  = string<br>    certificate_chain = optional(string)<br>    tags              = optional(map(any), {})<br>  }))</pre> | `{}` | no |
-| <a name="input_private_ca_issued_certificates"></a> [private\_ca\_issued\_certificates](#input\_private\_ca\_issued\_certificates) | List of Private CA issued certificates to use to create ACM certificates | <pre>map(object({<br>    certificate_authority_arn = string<br>    domain_name               = string<br>    early_renewal_duration    = optional(string)<br>    tags                      = optional(map(any), {})<br>  }))</pre> | `{}` | no |
+| <a name="input_amazon_issued_certificates"></a> [amazon\_issued\_certificates](#input\_amazon\_issued\_certificates) | List of Amazon-issued certificates to ACM create | <pre>map(object({<br>    domain_name               = string<br>    subject_alternative_names = optional(list(string), [])<br>    validation_method         = optional(string, null)<br>    key_algorithm             = optional(string, null)<br>    options = optional(object({<br>      certificate_transparency_logging_preference = optional(string, null)<br>    }))<br>    validation_option = optional(object({<br>      domain_name       = string<br>      validation_domain = string<br>    }))<br>    tags = optional(map(any), {})<br>  }))</pre> | `{}` | no |
+| <a name="input_imported_certificates"></a> [imported\_certificates](#input\_imported\_certificates) | List of imported certificates to use to create ACM certificates | <pre>map(object({<br>    private_key       = string<br>    certificate_body  = string<br>    certificate_chain = optional(string, null)<br>    tags              = optional(map(any), {})<br>  }))</pre> | `{}` | no |
+| <a name="input_private_ca_issued_certificates"></a> [private\_ca\_issued\_certificates](#input\_private\_ca\_issued\_certificates) | List of Private CA issued certificates to use to create ACM certificates | <pre>map(object({<br>    certificate_authority_arn = string<br>    domain_name               = string<br>    early_renewal_duration    = optional(string, null)<br>    tags                      = optional(map(any), {})<br>  }))</pre> | `{}` | no |
 | <a name="input_tags"></a> [tags](#input\_tags) | Resource Tags to use with the created ACM certificates | `map(any)` | `{}` | no |
 
 ## Outputs

modules/acm/main.tf

@@ -11,15 +11,15 @@ resource "aws_acm_certificate" "amazon_issued" {
   key_algorithm             = each.value.key_algorithm
 
   dynamic "options" {
-    for_each = length(try(each.value.options, {})) > 0 ? [1] : []
+    for_each = (try(each.value.options, null) != null && length(try(each.value.options, {})) > 0) ? [1] : []
 
     content {
       certificate_transparency_logging_preference = each.value.options.certificate_transparency_logging_preference
     }
   }
 
   dynamic "validation_option" {
-    for_each = length(try(each.value.validation_option, {})) > 0 ? [1] : []
+    for_each = (try(each.value.validation_option, null) != null && length(try(each.value.validation_option, {})) > 0) ? [1] : []
 
     content {
       domain_name       = each.value.validation_option.domain_name

modules/acm/variables.tf

@@ -7,10 +7,10 @@ variable "amazon_issued_certificates" {
   type = map(object({
     domain_name               = string
     subject_alternative_names = optional(list(string), [])
-    validation_method         = optional(string)
-    key_algorithm             = optional(string)
+    validation_method         = optional(string, null)
+    key_algorithm             = optional(string, null)
     options = optional(object({
-      certificate_transparency_logging_preference = optional(string)
+      certificate_transparency_logging_preference = optional(string, null)
     }))
     validation_option = optional(object({
       domain_name       = string
@@ -26,7 +26,7 @@ variable "imported_certificates" {
   type = map(object({
     private_key       = string
     certificate_body  = string
-    certificate_chain = optional(string)
+    certificate_chain = optional(string, null)
     tags              = optional(map(any), {})
   }))
   default = {}
@@ -37,7 +37,7 @@ variable "private_ca_issued_certificates" {
   type = map(object({
     certificate_authority_arn = string
     domain_name               = string
-    early_renewal_duration    = optional(string)
+    early_renewal_duration    = optional(string, null)
     tags                      = optional(map(any), {})
   }))
   default = {}