Allowing multiple SNS topics for alerting

Author: adenot

_variables.tf

@@ -75,7 +75,7 @@ variable "asg_memory_target" {
   description = "Target average memory percentage to track for autoscaling"
 }
 
-variable "alarm_sns_topic" {
-  default = ""
-  description = "Alarm topic to create and alert on ECS cluster metrics"
+variable "alarm_sns_topics" {
+  default = []
+  description = "Alarm topics to create and alert on ECS instance metrics"
 }

cloutwatch-alarms.tf

@@ -1,5 +1,5 @@
 resource "aws_cloudwatch_metric_alarm" "high_memory" {
-  count = "${var.alarm_sns_topic == "" ? 0 : 1}"
+  count = "${length(var.alarm_sns_topics) > 0 ? 1 : 0}"
 
   alarm_name                = "${data.aws_iam_account_alias.current.account_alias}-ecs-${var.name}-high-memory"
   comparison_operator       = "GreaterThanOrEqualToThreshold"
@@ -10,15 +10,16 @@ resource "aws_cloudwatch_metric_alarm" "high_memory" {
   statistic                 = "Maximum"
   threshold                 = "80"
   alarm_description         = "Cluster node memory above threshold"
-  alarm_actions             = ["${var.alarm_sns_topic}"]
+  alarm_actions             = var.alarm_sns_topics
+  ok_actions                = var.alarm_sns_topics
 
   dimensions = {
     ClusterName = "${aws_ecs_cluster.ecs.name}"
   }
 }
 
 resource "aws_cloudwatch_metric_alarm" "high_cpu" {
-  count = "${var.alarm_sns_topic == "" ? 0 : 1}"
+  count = "${length(var.alarm_sns_topics) > 0 ? 1 : 0}"
 
   alarm_name                = "${data.aws_iam_account_alias.current.account_alias}-ecs-${var.name}-high-cpu"
   comparison_operator       = "GreaterThanOrEqualToThreshold"
@@ -29,7 +30,8 @@ resource "aws_cloudwatch_metric_alarm" "high_cpu" {
   statistic                 = "Maximum"
   threshold                 = "80"
   alarm_description         = "Cluster node CPU above threshold"
-  alarm_actions             = ["${var.alarm_sns_topic}"]
+  alarm_actions             = var.alarm_sns_topics
+  ok_actions                = var.alarm_sns_topics
 
   dimensions = {
     ClusterName = "${aws_ecs_cluster.ecs.name}"