1430.tf

gistfile1.txt

#Prep
provider "aws" {
  region = "eu-central-1"
}

resource "random_id" "alarm" {
  byte_length = 8
}

#IAM
resource "aws_iam_role" "ecs_autoscale" {
  name = "${format("%s-%s", "role", random_id.alarm.hex)}"

  assume_role_policy = <<EOF
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "application-autoscaling.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ] 
}
EOF
}

resource "aws_iam_role_policy_attachment" "ecs_autoscale_policy_attach" {
  role       = "${aws_iam_role.ecs_autoscale.id}"
  policy_arn = "arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceAutoscaleRole"
}

#ECS
resource "aws_ecs_cluster" "ecs" {
  name = "${format("%s-%s", "ecs", random_id.alarm.hex)}"
}

resource "aws_ecs_task_definition" "task" {
  family = "${format("%s-%s", "task", random_id.alarm.hex)}"

  container_definitions = <<EOF
[{
	"name": "task",
	"image": "hello-world",
	"cpu": 10,
	"memory": 512,
	"essential": true,
	"portMappings": [{
		"containerPort": 80,
		"hostPort": 80
	}]
}]
EOF
}

resource "aws_ecs_service" "service1" {
  name            = "${format("%s-%s", "service1", random_id.alarm.hex)}"
  cluster         = "${aws_ecs_cluster.ecs.id}"
  task_definition = "${aws_ecs_task_definition.task.arn}"
}

resource "aws_ecs_service" "service2" {
  name            = "${format("%s-%s", "service2", random_id.alarm.hex)}"
  cluster         = "${aws_ecs_cluster.ecs.id}"
  task_definition = "${aws_ecs_task_definition.task.arn}"
}

resource "aws_ecs_service" "service3" {
  name            = "${format("%s-%s", "service3", random_id.alarm.hex)}"
  cluster         = "${aws_ecs_cluster.ecs.id}"
  task_definition = "${aws_ecs_task_definition.task.arn}"
}

# AppScaling1
resource "aws_appautoscaling_target" "ecs_target1" {
  role_arn           = "${aws_iam_role.ecs_autoscale.arn}"
  scalable_dimension = "ecs:service:DesiredCount"
  max_capacity       = "2"
  min_capacity       = "0"
  resource_id        = "service/${aws_ecs_cluster.ecs.name}/${aws_ecs_service.service1.name}"
  service_namespace  = "ecs"
  depends_on         = ["aws_ecs_service.service1"]
}

resource "aws_appautoscaling_policy" "ecs_policy1" {
  name                    = "scale-down-${count.index}"
  adjustment_type         = "ChangeInCapacity"
  cooldown                = 60
  metric_aggregation_type = "Maximum"
  resource_id             = "service/${aws_ecs_cluster.ecs.name}/${aws_ecs_service.service1.name}"
  scalable_dimension      = "ecs:service:DesiredCount"
  service_namespace       = "ecs"
  count                   = 50

  step_adjustment {
    metric_interval_upper_bound = 0
    scaling_adjustment          = -1
  }

  depends_on = ["aws_appautoscaling_target.ecs_target1", "aws_ecs_service.service1"]
}

#Alarm
resource "aws_cloudwatch_metric_alarm" "scale_out1" {
  alarm_name          = "${format("alarm-%s", count.index)}"
  alarm_actions       = ["${element(aws_appautoscaling_policy.ecs_policy1.*.arn, count.index)}"]
  metric_name         = "CPUUtilization"
  namespace           = "AWS/ECS"
  evaluation_periods  = "1"
  period              = "300"
  threshold           = "20"
  statistic           = "Maximum"
  comparison_operator = "GreaterThanOrEqualToThreshold"
  actions_enabled     = true
  count               = 50

  dimensions = {
    "ClusterName" = "${aws_ecs_cluster.ecs.name}"
    "ServiceName" = "${aws_ecs_service.service1.name}"
  }

  depends_on = ["aws_ecs_service.service1"]
}

# AppScaling2
resource "aws_appautoscaling_target" "ecs_target2" {
  role_arn           = "${aws_iam_role.ecs_autoscale.arn}"
  scalable_dimension = "ecs:service:DesiredCount"
  max_capacity       = "2"
  min_capacity       = "1"
  resource_id        = "service/${aws_ecs_cluster.ecs.name}/${aws_ecs_service.service2.name}"
  service_namespace  = "ecs"
  depends_on         = ["aws_ecs_service.service2"]
}

resource "aws_appautoscaling_policy" "ecs_policy2" {
  name                    = "scale-down-${count.index}"
  adjustment_type         = "ChangeInCapacity"
  cooldown                = 60
  metric_aggregation_type = "Maximum"
  resource_id             = "service/${aws_ecs_cluster.ecs.name}/${aws_ecs_service.service2.name}"
  scalable_dimension      = "ecs:service:DesiredCount"
  service_namespace       = "ecs"
  count                   = 50

  step_adjustment {
    metric_interval_upper_bound = 0
    scaling_adjustment          = -1
  }

  depends_on = ["aws_appautoscaling_target.ecs_target2", "aws_ecs_service.service2"]
}

#Alarm
resource "aws_cloudwatch_metric_alarm" "scale_out2" {
  alarm_name          = "${format("alarm-%s", count.index)}"
  alarm_actions       = ["${element(aws_appautoscaling_policy.ecs_policy2.*.arn, count.index)}"]
  metric_name         = "CPUUtilization"
  namespace           = "AWS/ECS"
  evaluation_periods  = "1"
  period              = "300"
  threshold           = "20"
  statistic           = "Maximum"
  comparison_operator = "GreaterThanOrEqualToThreshold"
  actions_enabled     = true
  count               = 50

  dimensions = {
    "ClusterName" = "${aws_ecs_cluster.ecs.name}"
    "ServiceName" = "${aws_ecs_service.service2.name}"
  }

  depends_on = ["aws_ecs_service.service2"]
}

# Appscaling 3
resource "aws_appautoscaling_target" "ecs_target3" {
  role_arn           = "${aws_iam_role.ecs_autoscale.arn}"
  scalable_dimension = "ecs:service:DesiredCount"
  max_capacity       = "2"
  min_capacity       = "1"
  resource_id        = "service/${aws_ecs_cluster.ecs.name}/${aws_ecs_service.service3.name}"
  service_namespace  = "ecs"
  depends_on         = ["aws_ecs_service.service3"]
}

resource "aws_appautoscaling_policy" "ecs_policy3" {
  name                    = "scale-down-${count.index}"
  adjustment_type         = "ChangeInCapacity"
  cooldown                = 60
  metric_aggregation_type = "Maximum"
  resource_id             = "service/${aws_ecs_cluster.ecs.name}/${aws_ecs_service.service3.name}"
  scalable_dimension      = "ecs:service:DesiredCount"
  service_namespace       = "ecs"
  count                   = 50

  step_adjustment {
    metric_interval_upper_bound = 0
    scaling_adjustment          = -1
  }

  depends_on = ["aws_appautoscaling_target.ecs_target3", "aws_ecs_service.service3"]
}

#Alarm
resource "aws_cloudwatch_metric_alarm" "scale_out3" {
  alarm_name          = "${format("alarm-%s", count.index)}"
  alarm_actions       = ["${element(aws_appautoscaling_policy.ecs_policy3.*.arn, count.index)}"]
  metric_name         = "CPUUtilization"
  namespace           = "AWS/ECS"
  evaluation_periods  = "1"
  period              = "300"
  threshold           = "20"
  statistic           = "Maximum"
  comparison_operator = "GreaterThanOrEqualToThreshold"
  actions_enabled     = true
  count               = 50

  dimensions = {
    "ClusterName" = "${aws_ecs_cluster.ecs.name}"
    "ServiceName" = "${aws_ecs_service.service3.name}"
  }

  depends_on = ["aws_ecs_service.service3"]
}