FEAT: Upgrade module to utilize terraform 0.12

Author: Sumit Sarkar

main.tf

@@ -1,5 +1,5 @@
 provider "aws" {
-  region = "${var.region}"
+  region = var.region
 }
 
 #
@@ -20,17 +20,17 @@ data "aws_iam_policy_document" "container_instance_ec2_assume_role" {
 
 resource "aws_iam_role" "container_instance_ec2" {
   name               = "${var.environment}ContainerInstanceProfile"
-  assume_role_policy = "${data.aws_iam_policy_document.container_instance_ec2_assume_role.json}"
+  assume_role_policy = data.aws_iam_policy_document.container_instance_ec2_assume_role.json
 }
 
 resource "aws_iam_role_policy_attachment" "ec2_service_role" {
-  role       = "${aws_iam_role.container_instance_ec2.name}"
+  role       = aws_iam_role.container_instance_ec2.name
   policy_arn = "arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceforEC2Role"
 }
 
 resource "aws_iam_instance_profile" "container_instance" {
-  name = "${aws_iam_role.container_instance_ec2.name}"
-  role = "${aws_iam_role.container_instance_ec2.name}"
+  name = aws_iam_role.container_instance_ec2.name
+  role = aws_iam_role.container_instance_ec2.name
 }
 
 #
@@ -52,11 +52,11 @@ data "aws_iam_policy_document" "ecs_assume_role" {
 
 resource "aws_iam_role" "ecs_service_role" {
   name               = "ecs${title(var.environment)}ServiceRole"
-  assume_role_policy = "${data.aws_iam_policy_document.ecs_assume_role.json}"
+  assume_role_policy = data.aws_iam_policy_document.ecs_assume_role.json
 }
 
 resource "aws_iam_role_policy_attachment" "ecs_service_role" {
-  role       = "${aws_iam_role.ecs_service_role.name}"
+  role       = aws_iam_role.ecs_service_role.name
   policy_arn = "arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceRole"
 }
 
@@ -77,31 +77,34 @@ data "aws_iam_policy_document" "ecs_autoscale_assume_role" {
 # Security group resources
 #
 resource "aws_security_group" "container_instance" {
-  vpc_id = "${var.vpc_id}"
+  vpc_id = var.vpc_id
 
   egress {
     from_port = 0
-    to_port = 0
-    protocol = "-1"
+    to_port   = 0
+    protocol  = "-1"
     cidr_blocks = [
-      "0.0.0.0/0"]
+      "0.0.0.0/0",
+    ]
   }
 
-  tags {
+  tags = {
     Name        = "sgContainerInstance"
-    Project     = "${var.project}"
-    Environment = "${var.environment}"
+    Project     = var.project
+    Environment = var.environment
   }
 }
 
 #
 # AutoScaling resources
 #
 data "template_file" "container_instance_base_cloud_config" {
-  template = "${file("${path.module}/cloud-config/base-container-instance.yml.tpl")}"
+  template = file(
+    "${path.module}/cloud-config/base-container-instance.yml.tpl",
+  )
 
-  vars {
-    ecs_cluster_name = "${aws_ecs_cluster.container_instance.name}"
+  vars = {
+    ecs_cluster_name = aws_ecs_cluster.container_instance.name
   }
 }
 
@@ -111,28 +114,24 @@ data "template_cloudinit_config" "container_instance_cloud_config" {
 
   part {
     content_type = "text/cloud-config"
-    content      = "${data.template_file.container_instance_base_cloud_config.rendered}"
+    content      = data.template_file.container_instance_base_cloud_config.rendered
   }
 
   part {
-    content_type = "${var.cloud_config_content_type}"
-    content      = "${var.cloud_config_content}"
+    content_type = var.cloud_config_content_type
+    content      = var.cloud_config_content
   }
 }
 
 data "aws_ami" "ecs_ami" {
-  count       = "${var.lookup_latest_ami ? 1 : 0}"
+  count       = var.lookup_latest_ami ? 1 : 0
   most_recent = true
 
   filter {
     name   = "name"
     values = ["amzn-ami-*-amazon-ecs-optimized"]
   }
 
-  filter {
-    name   = "owner-alias"
-    values = ["${var.ami_owners}"]
-  }
 
   filter {
     name   = "architecture"
@@ -143,59 +142,60 @@ data "aws_ami" "ecs_ami" {
     name   = "virtualization-type"
     values = ["hvm"]
   }
+  owners      = [var.ami_owners]
 }
 
 data "aws_ami" "user_ami" {
-  count  = "${var.lookup_latest_ami ? 0 : 1}"
-  owners = ["${var.ami_owners}"]
+  count  = var.lookup_latest_ami ? 0 : 1
+  owners = var.ami_owners
 
   filter {
     name   = "image-id"
-    values = ["${var.ami_id}"]
+    values = [var.ami_id]
   }
 }
 
 resource "aws_launch_configuration" "container_instance" {
-  count = "${length(var.instance_types)}"
+  count = length(var.instance_types)
 
   lifecycle {
     create_before_destroy = true
   }
 
   root_block_device {
-    volume_type = "${element(var.root_block_device_type, count.index)}"
-    volume_size = "${element(var.root_block_device_size, count.index)}"
+    volume_type = var.root_block_device_type[count.index]
+    volume_size = var.root_block_device_size[count.index]
   }
 
   name_prefix          = "lc${title(var.environment)}ContainerInstance-"
-  iam_instance_profile = "${aws_iam_instance_profile.container_instance.name}"
+  iam_instance_profile = aws_iam_instance_profile.container_instance.name
 
   # Using join() is a workaround for depending on conditional resources.
   # https://github.com/hashicorp/terraform/issues/2831#issuecomment-298751019
-  image_id = "${var.lookup_latest_ami ? join("", data.aws_ami.ecs_ami.*.image_id) : join("", data.aws_ami.user_ami.*.image_id)}"
+  image_id = var.lookup_latest_ami ? join("", data.aws_ami.ecs_ami.*.image_id) : join("", data.aws_ami.user_ami.*.image_id)
 
-  instance_type   = "${element(var.instance_types, count.index)}"
-  key_name        = "${var.key_name}"
-  security_groups = ["${aws_security_group.container_instance.id}"]
-  user_data       = "${data.template_cloudinit_config.container_instance_cloud_config.rendered}"
+  instance_type   = var.instance_types[count.index]
+  key_name        = var.key_name
+  security_groups = [aws_security_group.container_instance.id]
+  user_data       = data.template_cloudinit_config.container_instance_cloud_config.rendered
 }
 
 resource "aws_autoscaling_group" "container_instance" {
-  count = "${length(var.instance_types)}"
+  count = length(var.instance_types)
   lifecycle {
     create_before_destroy = true
   }
 
-  name                      = "asg${title(var.environment)}ContainerInstance${count.index}"
-  launch_configuration      = "${element(aws_launch_configuration.container_instance.*.name, count.index)}"
-  health_check_grace_period = "${var.health_check_grace_period}"
+  name = "asg${title(var.environment)}ContainerInstance${count.index}"
+  launch_configuration = aws_launch_configuration.container_instance.*.name[count.index]
+  health_check_grace_period = var.health_check_grace_period
   health_check_type         = "EC2"
-  desired_capacity          = "${element(var.desired_capacity, count.index)}"
+  desired_capacity          = var.desired_capacity[count.index]
   termination_policies      = ["OldestLaunchConfiguration", "Default"]
-  min_size                  = "${element(var.min_size, count.index)}"
-  max_size                  = "${element(var.max_size, count.index)}"
-  enabled_metrics           = ["${var.enabled_metrics}"]
-  vpc_zone_identifier       = ["${var.private_subnet_ids}"]
+  min_size                  = var.min_size[count.index]
+  max_size                  = var.max_size[count.index]
+  enabled_metrics           = var.enabled_metrics
+  vpc_zone_identifier       = var.private_subnet_ids
 
   tag {
     key                 = "Name"
@@ -205,19 +205,19 @@ resource "aws_autoscaling_group" "container_instance" {
 
   tag {
     key                 = "Project"
-    value               = "${var.project}"
+    value               = var.project
     propagate_at_launch = true
   }
 
   tag {
     key                 = "Environment"
-    value               = "${var.environment}"
+    value               = var.environment
     propagate_at_launch = true
   }
 
   tag {
     key                 = "spot-enabled"
-    value               = "${var.spot_enabled}"
+    value               = var.spot_enabled
     propagate_at_launch = true
   }
 }
@@ -233,103 +233,104 @@ resource "aws_ecs_cluster" "container_instance" {
 # CloudWatch resources
 #
 resource "aws_autoscaling_policy" "container_instance_scale_up" {
-  count = "${length(var.instance_types)}"
+  count = length(var.instance_types)
 
   name                   = "asgScalingPolicy${title(var.environment)}ClusterScaleUp${count.index}"
   scaling_adjustment     = 1
   adjustment_type        = "ChangeInCapacity"
-  cooldown               = "${element(var.scale_up_cooldown_seconds, count.index)}"
-  autoscaling_group_name = "${element(aws_autoscaling_group.container_instance.*.name, count.index)}"
+  cooldown               = var.scale_up_cooldown_seconds[count.index]
+  autoscaling_group_name = aws_autoscaling_group.container_instance.*.name[count.index]
 }
 
 resource "aws_autoscaling_policy" "container_instance_scale_down" {
-  count = "${length(var.instance_types)}"
+  count                  = length(var.instance_types)
   name                   = "asgScalingPolicy${title(var.environment)}ClusterScaleDown${count.index}"
   scaling_adjustment     = -1
   adjustment_type        = "ChangeInCapacity"
-  cooldown               = "${element(var.scale_down_cooldown_seconds, count.index)}"
-  autoscaling_group_name = "${element(aws_autoscaling_group.container_instance.*.name, count.index)}"
+  cooldown               = var.scale_down_cooldown_seconds[count.index]
+  autoscaling_group_name = aws_autoscaling_group.container_instance.*.name[count.index]
 }
 
 resource "aws_cloudwatch_metric_alarm" "container_instance_high_cpu" {
-  count = "${length(var.instance_types)}"
+  count = length(var.instance_types)
 
   alarm_name          = "alarm${title(var.environment)}ClusterCPUReservationHigh${count.index}"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "${element(var.high_cpu_evaluation_periods, count.index)}"
+  evaluation_periods  = var.high_cpu_evaluation_periods[count.index]
   metric_name         = "CPUReservation"
   namespace           = "AWS/ECS"
-  period              = "${element(var.high_cpu_period_seconds, count.index)}"
+  period              = var.high_cpu_period_seconds[count.index]
   statistic           = "Maximum"
-  threshold           = "${element(var.high_cpu_threshold_percent, count.index)}"
+  threshold           = var.high_cpu_threshold_percent[count.index]
 
-  dimensions {
-    ClusterName = "${aws_ecs_cluster.container_instance.name}"
+  dimensions = {
+    ClusterName = aws_ecs_cluster.container_instance.name
   }
 
   alarm_description = "Scale up if CPUReservation is above N% for N duration"
-  alarm_actions     = ["${element(aws_autoscaling_policy.container_instance_scale_up.*.arn, count.index)}"]
+  alarm_actions = [aws_autoscaling_policy.container_instance_scale_up.*.arn[count.index]]
 }
 
 resource "aws_cloudwatch_metric_alarm" "container_instance_low_cpu" {
-  count = "${length(var.instance_types)}"
+  count               = length(var.instance_types)
   alarm_name          = "alarm${title(var.environment)}ClusterCPUReservationLow${count.index}"
   comparison_operator = "LessThanOrEqualToThreshold"
-  evaluation_periods  = "${element(var.low_cpu_evaluation_periods, count.index)}"
+  evaluation_periods  = var.low_cpu_evaluation_periods[count.index]
   metric_name         = "CPUReservation"
   namespace           = "AWS/ECS"
-  period              = "${element(var.low_cpu_period_seconds, count.index)}"
+  period              = var.low_cpu_period_seconds[count.index]
   statistic           = "Maximum"
-  threshold           = "${element(var.low_cpu_threshold_percent, count.index)}"
+  threshold           = var.low_cpu_threshold_percent[count.index]
 
-  dimensions {
-    ClusterName = "${aws_ecs_cluster.container_instance.name}"
+  dimensions = {
+    ClusterName = aws_ecs_cluster.container_instance.name
   }
 
   alarm_description = "Scale down if the CPUReservation is below N% for N duration"
-  alarm_actions     = ["${element(aws_autoscaling_policy.container_instance_scale_down.*.arn, count.index)}"]
+  alarm_actions = [aws_autoscaling_policy.container_instance_scale_down.*.arn[count.index]]
 
-  depends_on = ["aws_cloudwatch_metric_alarm.container_instance_high_cpu"]
+  depends_on = [aws_cloudwatch_metric_alarm.container_instance_high_cpu]
 }
 
 resource "aws_cloudwatch_metric_alarm" "container_instance_high_memory" {
-  count = "${length(var.instance_types)}"
+  count               = length(var.instance_types)
   alarm_name          = "alarm${title(var.environment)}ClusterMemoryReservationHigh${count.index}"
   comparison_operator = "GreaterThanOrEqualToThreshold"
-  evaluation_periods  = "${element(var.high_memory_evaluation_periods, count.index)}"
+  evaluation_periods  = var.high_memory_evaluation_periods[count.index]
   metric_name         = "MemoryReservation"
   namespace           = "AWS/ECS"
-  period              = "${element(var.high_memory_period_seconds, count.index)}"
+  period              = var.high_memory_period_seconds[count.index]
   statistic           = "Maximum"
-  threshold           = "${element(var.high_memory_threshold_percent, count.index)}"
+  threshold           = var.high_memory_threshold_percent[count.index]
 
-  dimensions {
-    ClusterName = "${aws_ecs_cluster.container_instance.name}"
+  dimensions = {
+    ClusterName = aws_ecs_cluster.container_instance.name
   }
 
   alarm_description = "Scale up if the MemoryReservation is above N% for N duration"
-  alarm_actions     = ["${element(aws_autoscaling_policy.container_instance_scale_up.*.arn, count.index)}"]
+  alarm_actions = [aws_autoscaling_policy.container_instance_scale_up.*.arn[count.index]]
 
-  depends_on = ["aws_cloudwatch_metric_alarm.container_instance_low_cpu"]
+  depends_on = [aws_cloudwatch_metric_alarm.container_instance_low_cpu]
 }
 
 resource "aws_cloudwatch_metric_alarm" "container_instance_low_memory" {
-  count = "${length(var.instance_types)}"
+  count               = length(var.instance_types)
   alarm_name          = "alarm${title(var.environment)}ClusterMemoryReservationLow${count.index}"
   comparison_operator = "LessThanOrEqualToThreshold"
-  evaluation_periods  = "${element(var.low_memory_evaluation_periods, count.index)}"
+  evaluation_periods  = var.low_memory_evaluation_periods[count.index]
   metric_name         = "MemoryReservation"
   namespace           = "AWS/ECS"
-  period              = "${element(var.low_memory_period_seconds, count.index)}"
+  period              = var.low_memory_period_seconds[count.index]
   statistic           = "Maximum"
-  threshold           = "${element(var.low_memory_threshold_percent, count.index)}"
+  threshold           = var.low_memory_threshold_percent[count.index]
 
-  dimensions {
-    ClusterName = "${aws_ecs_cluster.container_instance.name}"
+  dimensions = {
+    ClusterName = aws_ecs_cluster.container_instance.name
   }
 
   alarm_description = "Scale down if the MemoryReservation is below N% for N duration"
-  alarm_actions     = ["${element(aws_autoscaling_policy.container_instance_scale_down.*.arn, count.index)}"]
+  alarm_actions = [aws_autoscaling_policy.container_instance_scale_down.*.arn[count.index]]
 
-  depends_on = ["aws_cloudwatch_metric_alarm.container_instance_high_memory"]
+  depends_on = [aws_cloudwatch_metric_alarm.container_instance_high_memory]
 }
+