refactor: use dynamic block for alarms config

README.md

@@ -245,6 +245,7 @@ for example.
 | <a name="input_create_ecr_repository"></a> [create\_ecr\_repository](#input\_create\_ecr\_repository) | Create an ECR repository for this service. | `bool` | `true` | no |
 | <a name="input_create_ingress_security_group"></a> [create\_ingress\_security\_group](#input\_create\_ingress\_security\_group) | Create a security group allowing ingress from target groups to the application ports. Disable this for target groups attached to a Network Loadbalancer. | `bool` | `true` | no |
 | <a name="input_deployment_circuit_breaker"></a> [deployment\_circuit\_breaker](#input\_deployment\_circuit\_breaker) | Deployment circuit breaker configuration. | <pre>object({<br>    enable   = bool<br>    rollback = bool<br>  })</pre> | <pre>{<br>  "enable": false,<br>  "rollback": false<br>}</pre> | no |
+| <a name="input_deployment_failure_detection_alarms"></a> [deployment\_failure\_detection\_alarms](#input\_deployment\_failure\_detection\_alarms) | CloudWatch alarms used to detect deployment failures. | <pre>object({<br>    enable      = bool<br>    rollback    = bool<br>    alarm_names = list(string)<br>  })</pre> | <pre>{<br>  "alarm_names": [],<br>  "enable": false,<br>  "rollback": false<br>}</pre> | no |
 | <a name="input_deployment_maximum_percent"></a> [deployment\_maximum\_percent](#input\_deployment\_maximum\_percent) | Upper limit (as a percentage of the service's desiredCount) of the number of running tasks that can be running in a service during a deployment. Not valid when using the `DAEMON` scheduling strategy. | `number` | `200` | no |
 | <a name="input_deployment_minimum_healthy_percent"></a> [deployment\_minimum\_healthy\_percent](#input\_deployment\_minimum\_healthy\_percent) | Lower limit (as a percentage of the service's desiredCount) of the number of running tasks that must remain running and healthy in a service during a deployment. | `number` | `100` | no |
 | <a name="input_desired_count"></a> [desired\_count](#input\_desired\_count) | Desired count of services to be started/running. | `number` | `0` | no |

main.tf

@@ -108,10 +108,14 @@ resource "aws_ecs_service" "this" {
     }
   }
 
-  alarms {
-    enable      = var.deployment_failure_detection_alarms.enable
-    rollback    = var.deployment_failure_detection_alarms.rollback
-    alarm_names = var.deployment_failure_detection_alarms.alarm_names
+  dynamic "alarms" {
+    for_each = var.deployment_failure_detection_alarms.enable ? [true] : []
+
+    content {
+      enable      = var.deployment_failure_detection_alarms.enable
+      rollback    = var.deployment_failure_detection_alarms.rollback
+      alarm_names = var.deployment_failure_detection_alarms.alarm_names
+    }
   }
 
   dynamic "load_balancer" {

variables.tf

@@ -97,11 +97,12 @@ variable "deployment_failure_detection_alarms" {
     rollback    = false
     alarm_names = []
   }
-  description = "Deployment circuit breaker configuration."
+
+  description = "CloudWatch alarms used to detect deployment failures."
   type = object({
-    enable      = optional(bool, true)
+    enable      = bool
     rollback    = bool
-    alarm_names = optional(list(string), [])
+    alarm_names = list(string)
   })
 }