Merge pull request #27 from steve-stonehouse/master

Adding variables for alarm evaluation periods.

README.md

@@ -173,6 +173,9 @@ resource "aws_rds_cluster_parameter_group" "aurora_cluster_postgres96_parameter_
 | azs | List of AZs to use | list | - | yes |
 | backup_retention_period | How long to keep backups for (in days) | string | `7` | no |
 | cw_alarms | Whether to enable CloudWatch alarms - requires `cw_sns_topic` is specified | string | `false` | no |
+| cw_eval_period_connections | Evaluation period for the DB connections alarms | string | `1` | no |
+| cw_eval_period_cpu | Evaluation period for the DB CPU alarms | string | `2` | no |
+| cw_eval_period_replica_lag | Evaluation period for the DB replica lag alarm | string | `5` | no |
 | cw_max_conns | Connection count beyond which to trigger a CloudWatch alarm | string | `500` | no |
 | cw_max_cpu | CPU threshold above which to alarm | string | `85` | no |
 | cw_max_replica_lag | Maximum Aurora replica lag in milliseconds above which to alarm | string | `2000` | no |

alarms.tf

@@ -2,7 +2,7 @@ resource "aws_cloudwatch_metric_alarm" "alarm_rds_DatabaseConnections_writer" {
   count               = "${var.cw_alarms ? 1 : 0}"
   alarm_name          = "${aws_rds_cluster.default.id}-alarm-rds-writer-DatabaseConnections"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "1"
+  evaluation_periods  = "${var.cw_eval_period_connections}"
   metric_name         = "DatabaseConnections"
   namespace           = "AWS/RDS"
   period              = "60"
@@ -22,7 +22,7 @@ resource "aws_cloudwatch_metric_alarm" "alarm_rds_DatabaseConnections_reader" {
   count               = "${var.cw_alarms && var.replica_count > 0 ? 1 : 0}"
   alarm_name          = "${aws_rds_cluster.default.id}-alarm-rds-reader-DatabaseConnections"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "1"
+  evaluation_periods  = "${var.cw_eval_period_connections}"
   metric_name         = "DatabaseConnections"
   namespace           = "AWS/RDS"
   period              = "60"
@@ -42,7 +42,7 @@ resource "aws_cloudwatch_metric_alarm" "alarm_rds_CPU_writer" {
   count               = "${var.cw_alarms ? 1 : 0}"
   alarm_name          = "${aws_rds_cluster.default.id}-alarm-rds-writer-CPU"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "2"
+  evaluation_periods  = "${var.cw_eval_period_cpu}"
   metric_name         = "CPUUtilization"
   namespace           = "AWS/RDS"
   period              = "60"
@@ -62,7 +62,7 @@ resource "aws_cloudwatch_metric_alarm" "alarm_rds_CPU_reader" {
   count               = "${var.cw_alarms && var.replica_count > 0 ? 1 : 0}"
   alarm_name          = "${aws_rds_cluster.default.id}-alarm-rds-reader-CPU"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "2"
+  evaluation_periods  = "${var.cw_eval_period_cpu}"
   metric_name         = "CPUUtilization"
   namespace           = "AWS/RDS"
   period              = "60"
@@ -82,7 +82,7 @@ resource "aws_cloudwatch_metric_alarm" "alarm_rds_replica_lag" {
   count               = "${var.cw_alarms && var.replica_count > 0 ? 1 : 0}"
   alarm_name          = "${aws_rds_cluster.default.id}-alarm-rds-reader-AuroraReplicaLag"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "5"
+  evaluation_periods  = "${var.cw_eval_period_replica_lag}"
   metric_name         = "AuroraReplicaLag"
   namespace           = "AWS/RDS"
   period              = "60"

variables.tf

@@ -170,6 +170,24 @@ variable "cw_max_replica_lag" {
   description = "Maximum Aurora replica lag in milliseconds above which to alarm"
 }
 
+variable "cw_eval_period_connections" {
+  type        = "string"
+  default     = "1"
+  description = "Evaluation period for the DB connections alarms"
+}
+
+variable "cw_eval_period_cpu" {
+  type        = "string"
+  default     = "2"
+  description = "Evaluation period for the DB CPU alarms"
+}
+
+variable "cw_eval_period_replica_lag" {
+  type        = "string"
+  default     = "5"
+  description = "Evaluation period for the DB replica lag alarm"
+}
+
 variable "engine" {
   type        = "string"
   default     = "aurora"