added optional sns topic in alarm actions (#31)

Author: mayank0202

README.md

@@ -59,7 +59,7 @@ In order to run all checks at any point run the following command:
 
 | Name | Version |
 |------|---------|
-| <a name="provider_aws"></a> [aws](#provider\_aws) | 4.24.0 |
+| <a name="provider_aws"></a> [aws](#provider\_aws) | 5.44.0 |
 
 ## Modules
 
@@ -90,6 +90,7 @@ No modules.
 | <a name="input_name_prefix"></a> [name\_prefix](#input\_name\_prefix) | Name prefix for resources on AWS | `any` | n/a | yes |
 | <a name="input_scale_target_max_capacity"></a> [scale\_target\_max\_capacity](#input\_scale\_target\_max\_capacity) | The max capacity of the scalable target | `number` | `5` | no |
 | <a name="input_scale_target_min_capacity"></a> [scale\_target\_min\_capacity](#input\_scale\_target\_min\_capacity) | The min capacity of the scalable target | `number` | `1` | no |
+| <a name="input_sns_topic_arn"></a> [sns\_topic\_arn](#input\_sns\_topic\_arn) | The ARN of an SNS topic to send notifications on alarm actions. | `string` | `""` | no |
 | <a name="input_tags"></a> [tags](#input\_tags) | Resource tags | `map(string)` | `{}` | no |
 
 ## Outputs

main.tf

@@ -14,8 +14,10 @@ resource "aws_cloudwatch_metric_alarm" "cpu_high" {
     ClusterName = var.ecs_cluster_name
     ServiceName = var.ecs_service_name
   }
-  alarm_actions = [aws_appautoscaling_policy.scale_up_policy.arn]
-
+  alarm_actions = [
+    aws_appautoscaling_policy.scale_up_policy.arn,
+    var.sns_topic_arn != "" ? var.sns_topic_arn : null
+  ]
   tags = var.tags
 }
 
@@ -35,8 +37,10 @@ resource "aws_cloudwatch_metric_alarm" "cpu_low" {
     ClusterName = var.ecs_cluster_name
     ServiceName = var.ecs_service_name
   }
-  alarm_actions = [aws_appautoscaling_policy.scale_down_policy.arn]
-
+  alarm_actions = [
+    aws_appautoscaling_policy.scale_down_policy.arn,
+    var.sns_topic_arn != "" ? var.sns_topic_arn : null
+  ]
   tags = var.tags
 }
 

variables.tf

@@ -66,3 +66,10 @@ variable "scale_target_min_capacity" {
   default     = 1
   type        = number
 }
+
+variable "sns_topic_arn" {
+  # Optional ARN of an SNS topic for sending notifications
+  type        = string
+  description = "The ARN of an SNS topic to send notifications on alarm actions."
+  default     = "" # Set an empty string as default to avoid potential errors
+}