Adding alarms and scaling policies to enable autoscaling on the group

cn-terraform · Jul 10, 2019 · 57a9ae5 · 57a9ae5
1 parent 93d101c
commit 57a9ae5
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diff --git a/outputs.tf b/outputs.tf
@@ -57,3 +57,67 @@ output "asg_target_group_arns" {
     description = "(Optional) list of Target Group ARNs that apply to this AutoScaling Group."
     value       = aws_autoscaling_group.asg.target_group_arns
 }
+
+# ---------------------------------------------------------------------------------------------------------------------
+# AUTOSCALING POLICIES
+# ---------------------------------------------------------------------------------------------------------------------
+output "cpu_high_name" {
+    description = "The scaling policy's name."
+    value       = aws_autoscaling_policy.cpu_high.name
+}
+output "cpu_high_arn" {
+    description = "The ARN assigned by AWS to the scaling policy."
+    value       = aws_autoscaling_policy.cpu_high.arn
+}
+output "cpu_high_autoscaling_group_name" {
+    description = "The scaling policy's assigned autoscaling group"
+    value       = aws_autoscaling_policy.cpu_high.autoscaling_group_name
+}
+output "cpu_high_adjustment_type" {
+    description = "The scaling policy's adjustment type."
+    value       = aws_autoscaling_policy.cpu_high.adjustment_type
+}
+output "cpu_high_policy_type" {
+    description = "The scaling policy's type."
+    value       = aws_autoscaling_policy.cpu_high.policy_type
+}
+output "cpu_low_name" {
+    description = "The scaling policy's name."
+    value       = aws_autoscaling_policy.cpu_low.name
+}
+output "cpu_low_arn" {
+    description = "The ARN assigned by AWS to the scaling policy."
+    value       = aws_autoscaling_policy.cpu_low.arn
+}
+output "cpu_low_autoscaling_group_name" {
+    description = "The scaling policy's assigned autoscaling group"
+    value       = aws_autoscaling_policy.cpu_low.autoscaling_group_name
+}
+output "cpu_low_adjustment_type" {
+    description = "The scaling policy's adjustment type."
+    value       = aws_autoscaling_policy.cpu_low.adjustment_type
+}
+output "cpu_low_policy_type" {
+    description = "The scaling policy's type."
+    value       = aws_autoscaling_policy.cpu_low.policy_type
+}
+
+# ---------------------------------------------------------------------------------------------------------------------
+# CLOUDWATCH ALARMS
+# ---------------------------------------------------------------------------------------------------------------------
+output "cpu_high_alarm_id" {
+    description = "The ID of the health check."
+    value       = aws_cloudwatch_metric_alarm.cpu_high_alarm.id
+}
+output "cpu_high_alarm_arn" {
+    description = "(Optional) list of Target Group ARNs that apply to this AutoScaling Group."
+    value       = aws_cloudwatch_metric_alarm.cpu_high_alarm.arn
+}
+output "cpu_low_alarm_id" {
+    description = "The ID of the health check."
+    value       = aws_cloudwatch_metric_alarm.cpu_low_alarm.id
+}
+output "cpu_low_alarm_arn" {
+    description = "(Optional) list of Target Group ARNs that apply to this AutoScaling Group."
+    value       = aws_cloudwatch_metric_alarm.cpu_low_alarm.arn
+}
diff --git a/scaling_policies.tf b/scaling_policies.tf
@@ -0,0 +1,55 @@
+# ---------------------------------------------------------------------------------------------------------------------
+# AUTOSCALING POLICIES
+# ---------------------------------------------------------------------------------------------------------------------
+# Scaling UP - CPU High
+resource "aws_autoscaling_policy" "cpu_high" {
+    name                   = "${var.name_preffix}-cpu-high"
+    autoscaling_group_name = "${aws_autoscaling_group.asg.name}"
+    adjustment_type        = "ChangeInCapacity"
+    policy_type            = "SimpleScaling"
+    scaling_adjustment     = "1"
+    cooldown               = "300"
+}
+# Scaling DOWN - CPU Low
+resource "aws_autoscaling_policy" "cpu_low" {
+    name                   = "${var.name_preffix}-cpu-high"
+    autoscaling_group_name = "${aws_autoscaling_group.asg.name}"
+    adjustment_type        = "ChangeInCapacity"
+    policy_type            = "SimpleScaling"
+    scaling_adjustment     = "-1"
+    cooldown               = "300"
+}
+
+# ---------------------------------------------------------------------------------------------------------------------
+# CLOUDWATCH METRIC ALARMS
+# ---------------------------------------------------------------------------------------------------------------------
+resource "aws_cloudwatch_metric_alarm" "cpu_high_alarm" {
+    alarm_name          = "${var.name_preffix}-cpu-high-alarm"
+    comparison_operator = "GreaterThanOrEqualToThreshold"
+    evaluation_periods  = "2"
+    metric_name         = "CPUUtilization"
+    namespace           = "AWS/EC2"
+    period              = "60"
+    statistic           = "Average"
+    threshold           = "80"
+    actions_enabled     = true
+    alarm_actions       = ["${aws_autoscaling_policy.cpu_high.arn}"]
+    dimensions = {
+        "AutoScalingGroupName" = "${aws_autoscaling_group.asg.name}"
+    }
+}
+resource "aws_cloudwatch_metric_alarm" "cpu_low_alarm" {
+    alarm_name          = "${var.name_preffix}-cpu-low-alarm"
+    comparison_operator = "LessThanOrEqualToThreshold"
+    evaluation_periods  = "2"
+    metric_name         = "CPUUtilization"
+    namespace           = "AWS/EC2"
+    period              = "60"
+    statistic           = "Average"
+    threshold           = "10"
+    actions_enabled     = true
+    alarm_actions       = ["${aws_autoscaling_policy.cpu_low.arn}"]
+    dimensions = {
+        "AutoScalingGroupName" = "${aws_autoscaling_group.asg.name}"
+    }
+}