Add cache name to alarm names

This makes alarm names unique when more than one elasticache instance
exists with an AWS account. Otherwise, the alarm names conflict with
each other.

Author: Sharp Hall

main.tf

@@ -56,7 +56,7 @@ resource "aws_elasticache_subnet_group" "default" {
 #
 
 resource "aws_cloudwatch_metric_alarm" "cpu" {
-  alarm_name          = "alarmCacheClusterCPUUtilization"
+  alarm_name          = "alarmCacheClusterCPUUtilization-${var.cache_name}"
   alarm_description   = "Cache cluster CPU utilization"
   comparison_operator = "GreaterThanThreshold"
   evaluation_periods  = "1"
@@ -74,7 +74,7 @@ resource "aws_cloudwatch_metric_alarm" "cpu" {
 }
 
 resource "aws_cloudwatch_metric_alarm" "memory_free" {
-  alarm_name          = "alarmCacheClusterFreeableMemory"
+  alarm_name          = "alarmCacheClusterFreeableMemory-${var.cache_name}"
   alarm_description   = "Cache cluster freeable memory"
   comparison_operator = "LessThanThreshold"
   evaluation_periods  = "1"