fix: added validation to CBR input (#842)

Author: aamadeuss

README.md

@@ -338,7 +338,7 @@ Optionally, you need the following permissions to attach Access Management tags
 | <a name="input_addons"></a> [addons](#input\_addons) | Map of OCP cluster add-on versions to install (NOTE: The 'vpc-block-csi-driver' add-on is installed by default for VPC clusters and 'ibm-storage-operator' is installed by default in OCP 4.15 and later, however you can explicitly specify it here if you wish to choose a later version than the default one). For full list of all supported add-ons and versions, see https://cloud.ibm.com/docs/containers?topic=containers-supported-cluster-addon-versions | <pre>object({<br/>    debug-tool = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    image-key-synchronizer = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    openshift-data-foundation = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    vpc-file-csi-driver = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    static-route = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    cluster-autoscaler = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    vpc-block-csi-driver = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    ibm-storage-operator = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>    openshift-ai = optional(object({<br/>      version         = optional(string)<br/>      parameters_json = optional(string)<br/>    }))<br/>  })</pre> | `{}` | no |
 | <a name="input_allow_default_worker_pool_replacement"></a> [allow\_default\_worker\_pool\_replacement](#input\_allow\_default\_worker\_pool\_replacement) | (Advanced users) Set to true to allow the module to recreate a default worker pool. If you wish to make any change to the default worker pool which requires the re-creation of the default pool follow these [steps](https://github.com/terraform-ibm-modules/terraform-ibm-base-ocp-vpc?tab=readme-ov-file#important-considerations-for-terraform-and-default-worker-pool). | `bool` | `false` | no |
 | <a name="input_attach_ibm_managed_security_group"></a> [attach\_ibm\_managed\_security\_group](#input\_attach\_ibm\_managed\_security\_group) | Specify whether to attach the IBM-defined default security group (whose name is kube-<clusterid>) to all worker nodes. Only applicable if `custom_security_group_ids` is set. | `bool` | `true` | 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/>    rule_contexts = list(object({<br/>      attributes = optional(list(object({<br/>        name  = string<br/>        value = string<br/>    }))) }))<br/>    enforcement_mode = string<br/>    tags = optional(list(object({<br/>      name  = string<br/>      value = string<br/>    })), [])<br/>    operations = optional(list(object({<br/>      api_types = list(object({<br/>        api_type_id = string<br/>      }))<br/>    })))<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/>    rule_contexts = list(object({<br/>      attributes = optional(list(object({<br/>        name  = string<br/>        value = string<br/>    }))) }))<br/>    enforcement_mode = string<br/>    tags = optional(list(object({<br/>      name  = string<br/>      value = string<br/>    })), [])<br/>    operations = optional(list(object({<br/>      api_types = list(object({<br/>        api_type_id = string<br/>      }))<br/>    })))<br/>  }))</pre> | `[]` | no |
 | <a name="input_cluster_config_endpoint_type"></a> [cluster\_config\_endpoint\_type](#input\_cluster\_config\_endpoint\_type) | Specify which type of endpoint to use for cluster config access: 'default', 'private', 'vpe', 'link'. A 'default' value uses the default endpoint of the cluster. | `string` | `"default"` | no |
 | <a name="input_cluster_name"></a> [cluster\_name](#input\_cluster\_name) | The name that is assigned to the provisioned cluster. | `string` | n/a | yes |
 | <a name="input_cluster_ready_when"></a> [cluster\_ready\_when](#input\_cluster\_ready\_when) | The cluster is ready based on one of the following:: MasterNodeReady (not recommended), OneWorkerNodeReady, Normal, IngressReady | `string` | `"IngressReady"` | no |

variables.tf

@@ -430,8 +430,12 @@ variable "cbr_rules" {
       }))
     })))
   }))
-  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 {
+    condition     = length(var.cbr_rules) <= 1
+    error_message = "Only one CBR rule is allowed."
+  }
 }
 
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