fix: added validation to CBR input (#305)

Author: aamadeuss

README.md

@@ -121,7 +121,7 @@ For more information on access and permissions, see <https://cloud.ibm.com/docs/
 | <a name="input_app_config_plan"></a> [app\_config\_plan](#input\_app\_config\_plan) | Plan for the App Configuration service instance, valid plans are lite, basic, standardv2, and enterprise. | `string` | `"lite"` | no |
 | <a name="input_app_config_service_endpoints"></a> [app\_config\_service\_endpoints](#input\_app\_config\_service\_endpoints) | Service Endpoints for the App Configuration service instance, valid endpoints are public or public-and-private. | `string` | `"public-and-private"` | no |
 | <a name="input_app_config_tags"></a> [app\_config\_tags](#input\_app\_config\_tags) | Optional list of tags to be added to the App Config instance. | `list(string)` | `[]` | no |
-| <a name="input_cbr_rules"></a> [cbr\_rules](#input\_cbr\_rules) | The list of context-based restriction rules to create. | <pre>list(object({<br/>    description = string<br/>    account_id  = string<br/>    tags = optional(list(object({<br/>      name  = string<br/>      value = string<br/>    })), [])<br/>    rule_contexts = list(object({<br/>      attributes = optional(list(object({<br/>        name  = string<br/>        value = string<br/>    }))) }))<br/>    enforcement_mode = string<br/>  }))</pre> | `[]` | no |
+| <a name="input_cbr_rules"></a> [cbr\_rules](#input\_cbr\_rules) | The context-based restrictions rule to create. Only one rule is allowed. | <pre>list(object({<br/>    description = string<br/>    account_id  = string<br/>    tags = optional(list(object({<br/>      name  = string<br/>      value = string<br/>    })), [])<br/>    rule_contexts = list(object({<br/>      attributes = optional(list(object({<br/>        name  = string<br/>        value = string<br/>    }))) }))<br/>    enforcement_mode = string<br/>  }))</pre> | `[]` | no |
 | <a name="input_config_aggregator_enterprise_account_group_ids_to_assign"></a> [config\_aggregator\_enterprise\_account\_group\_ids\_to\_assign](#input\_config\_aggregator\_enterprise\_account\_group\_ids\_to\_assign) | A list of enterprise account group IDs to assign the trusted profile template to in order for the accounts to be scanned. Supports passing the string 'all' in the list to assign to all account groups. Only applies if `enable_config_aggregator` is true and a value is being passed for `config_aggregator_enterprise_id`. | `list(string)` | <pre>[<br/>  "all"<br/>]</pre> | no |
 | <a name="input_config_aggregator_enterprise_account_ids_to_assign"></a> [config\_aggregator\_enterprise\_account\_ids\_to\_assign](#input\_config\_aggregator\_enterprise\_account\_ids\_to\_assign) | A list of enterprise account IDs to assign the trusted profile template to in order for the accounts to be scanned. Supports passing the string 'all' in the list to assign to all accounts. Only applies if `enable_config_aggregator` is true and a value is being passed for `config_aggregator_enterprise_id`. | `list(string)` | `[]` | no |
 | <a name="input_config_aggregator_enterprise_id"></a> [config\_aggregator\_enterprise\_id](#input\_config\_aggregator\_enterprise\_id) | If the account is an enterprise account, this value should be set to the enterprise ID (NOTE: This is different to the account ID). | `string` | `null` | no |

variables.tf

@@ -184,9 +184,13 @@ variable "cbr_rules" {
     }))) }))
     enforcement_mode = string
   }))
-  description = "The list of context-based restriction rules to create."
+  description = "The context-based restrictions rule to create. Only one rule is allowed."
   default     = []
   # Validation happens in the rule module
+  validation {
+    condition     = length(var.cbr_rules) <= 1
+    error_message = "Only one CBR rule is allowed."
+  }
 }
 
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