Fix "Interpolation-only expressions are deprecated" warning

Author: ddosia

modules/bastion/iam.tf

@@ -1,6 +1,6 @@
 resource "aws_iam_instance_profile" "s3_readonly" {
   name = "${var.name}-s3-readonly"
-  role = "${aws_iam_role.s3_readonly.name}"
+  role = aws_iam_role.s3_readonly.name
 }
 
 resource "aws_iam_role" "s3_readonly" {
@@ -25,7 +25,7 @@ EOF
 
 resource "aws_iam_role_policy" "s3_readonly_policy" {
   name = "${var.name}-s3-readonly-policy"
-  role = "${aws_iam_role.s3_readonly.id}"
+  role = aws_iam_role.s3_readonly.id
 
   policy = <<EOF
 {
@@ -38,7 +38,7 @@ resource "aws_iam_role_policy" "s3_readonly_policy" {
                 "s3:Get*"
             ],
             "Resource": [
-              "${var.s3_bucket_arn}",
+              var.s3_bucket_arn,
               "${var.s3_bucket_arn}/*"
             ]
         }

modules/bastion/main.tf

@@ -1,18 +1,18 @@
 resource "aws_security_group" "bastion" {
-  name        = "${var.name}"
-  vpc_id      = "${var.vpc_id}"
+  name        = var.name
+  vpc_id      = var.vpc_id
   description = "Bastion security group (only SSH inbound access is allowed)"
 
   tags {
-    Name = "${var.name}"
+    Name = var.name
   }
 
   ingress {
     protocol  = "tcp"
     from_port = 22
     to_port   = 22
 
-    cidr_blocks = "${var.allow_ssh_cidrs}"
+    cidr_blocks = var.allow_ssh_cidrs
   }
 
   egress {
@@ -31,48 +31,48 @@ resource "aws_security_group" "bastion" {
 }
 
 data "template_file" "user_data" {
-  template = "${file("${path.module}/user-data/user-data.sh")}"
-
-  vars {
-    s3_bucket_name              = "${var.s3_bucket_name}"
-    s3_bucket_uri               = "${var.s3_bucket_uri}"
-    ssh_user                    = "${var.ssh_user}"
-    keys_update_frequency       = "${var.keys_update_frequency}"
-    enable_hourly_cron_updates  = "${var.enable_hourly_cron_updates}"
-    additional_user_data_script = "${var.additional_user_data_script}"
+  template = file("${path.module}/user-data/user-data.sh")
+
+  vars = {
+    s3_bucket_name              = var.s3_bucket_name
+    s3_bucket_uri               = var.s3_bucket_uri
+    ssh_user                    = var.ssh_user
+    keys_update_frequency       = var.keys_update_frequency
+    enable_hourly_cron_updates  = var.enable_hourly_cron_updates
+    additional_user_data_script = var.additional_user_data_script
   }
 }
 
 resource "aws_launch_configuration" "bastion" {
-  name_prefix                 = "${var.name}"
-  image_id                    = "${var.ami}"
-  instance_type               = "${var.instance_type}"
-  key_name                    = "${var.keypair}"
-  user_data                   = "${data.template_file.user_data.rendered}"
-  associate_public_ip_address = "${var.associate_public_ip_address}"
+  name_prefix                 = var.name
+  image_id                    = var.ami
+  instance_type               = var.instance_type
+  key_name                    = var.keypair
+  user_data                   = data.template_file.user_data.rendered
+  associate_public_ip_address = var.associate_public_ip_address
 
   security_groups = [
-    "${compact(concat(list(aws_security_group.bastion.id), split(",", "${var.security_group_ids}")))}",
+    compact(concat(list(aws_security_group.bastion.id), split(",", var.security_group_ids))),
   ]
 
-  iam_instance_profile = "${aws_iam_instance_profile.s3_readonly.name}"
+  iam_instance_profile = aws_iam_instance_profile.s3_readonly.name
 
   lifecycle {
     create_before_destroy = true
   }
 }
 
 resource "aws_autoscaling_group" "bastion" {
-  name                      = "${var.name}"
-  vpc_zone_identifier       = ["${split(",", var.subnet_ids)}"]
+  name                      = var.name
+  vpc_zone_identifier       = [split(",", var.subnet_ids)]
   desired_capacity          = "1"
   min_size                  = "1"
   max_size                  = "1"
   health_check_grace_period = "60"
   health_check_type         = "EC2"
   force_delete              = false
   wait_for_capacity_timeout = 0
-  launch_configuration      = "${aws_launch_configuration.bastion.name}"
+  launch_configuration      = aws_launch_configuration.bastion.name
 
   enabled_metrics = [
     "GroupMinSize",
@@ -87,13 +87,13 @@ resource "aws_autoscaling_group" "bastion" {
 
   tag {
     key                 = "Name"
-    value               = "${var.name}"
+    value               = var.name
     propagate_at_launch = true
   }
 
   tag {
     key                 = "EIP"
-    value               = "${var.eip}"
+    value               = var.eip
     propagate_at_launch = true
   }
 

modules/bastion/output.tf

@@ -1,7 +1,7 @@
 output "ssh_user" {
-  value = "${var.ssh_user}"
+  value = var.ssh_user
 }
 
 output "security_group_id" {
-  value = "${aws_security_group.bastion.id}"
+  value = aws_security_group.bastion.id
 }

modules/nat/main.tf

@@ -1,18 +1,18 @@
 resource "aws_eip" "nat" {
   vpc = true
 
-  count = "${length(var.azs)}" # Comment out count to only have 1 NAT
+  count = length(var.azs) # Comment out count to only have 1 NAT
 
   lifecycle {
     create_before_destroy = true
   }
 }
 
 resource "aws_nat_gateway" "nat" {
-  count = "${length(var.azs)}" # Comment out count to only have 1 NAT
+  count = length(var.azs) # Comment out count to only have 1 NAT
 
-  allocation_id = "${element(aws_eip.nat.*.id, count.index)}"
-  subnet_id     = "${element(split(",", var.public_subnet_ids), count.index)}"
+  allocation_id = element(aws_eip.nat.*.id, count.index)
+  subnet_id     = element(split(",", var.public_subnet_ids), count.index)
 
   lifecycle {
     create_before_destroy = true

modules/nat/output.tf

@@ -1,7 +1,7 @@
 output "nat_gateway_ids" {
-  value = "${join(",", aws_nat_gateway.nat.*.id)}"
+  value = join(",", aws_nat_gateway.nat.*.id)
 }
 
 output "public_ip" {
-  value = "${aws_eip.nat.public_ip}"
+  value = aws_eip.nat.public_ip
 }

modules/network-acl/main.tf

@@ -1,6 +1,6 @@
 resource "aws_network_acl" "acl" {
-  vpc_id     = "${var.vpc_id}"
-  subnet_ids = ["${concat(split(",", var.public_subnet_ids), split(",", var.private_app_subnet_ids))}"]
+  vpc_id     = var.vpc_id
+  subnet_ids = [concat(split(",", var.public_subnet_ids), split(",", var.private_app_subnet_ids))]
 
   ingress {
     protocol   = "-1"
@@ -21,6 +21,6 @@ resource "aws_network_acl" "acl" {
   }
 
   tags {
-    Name = "${var.name}"
+    Name = var.name
   }
 }

modules/network-acl/output.tf

@@ -1,3 +1,3 @@
 output "network_acl_id" {
-  value = "${aws_network_acl.acl.id}"
+  value = aws_network_acl.acl.id
 }

modules/network.tf

@@ -83,100 +83,100 @@ module "vpc" {
   source = "./vpc"
 
   name     = "${var.name}-vpc"
-  vpc_cidr = "${var.vpc_cidr}"
+  vpc_cidr = var.vpc_cidr
 }
 
 module "public_subnet" {
   source = "./public-subnet"
 
   name           = "${var.name}-public"
-  vpc_id         = "${module.vpc.vpc_id}"
-  public_subnets = "${var.public_subnets}"
-  azs            = "${var.azs}"
+  vpc_id         = module.vpc.vpc_id
+  public_subnets = var.public_subnets
+  azs            = var.azs
 }
 
 module "nat" {
   source = "./nat"
 
   name              = "${var.name}-nat"
-  azs               = "${var.azs}"
-  public_subnet_ids = "${module.public_subnet.subnet_ids}"
+  azs               = var.azs
+  public_subnet_ids = module.public_subnet.subnet_ids
 }
 
 module "private_app_subnet" {
   source = "./private-app-subnet"
 
   name                = "${var.name}-private-app"
-  vpc_id              = "${module.vpc.vpc_id}"
-  private_app_subnets = "${var.private_app_subnets}"
-  azs                 = "${var.azs}"
+  vpc_id              = module.vpc.vpc_id
+  private_app_subnets = var.private_app_subnets
+  azs                 = var.azs
 
-  nat_gateway_ids = "${module.nat.nat_gateway_ids}"
+  nat_gateway_ids = module.nat.nat_gateway_ids
 }
 
 module "private_persistence_subnet" {
   source = "./private-persistence-subnet"
 
   name                        = "${var.name}-private-persistence"
-  vpc_id                      = "${module.vpc.vpc_id}"
-  private_persistence_subnets = "${var.private_persistence_subnets}"
-  azs                         = "${var.azs}"
+  vpc_id                      = module.vpc.vpc_id
+  private_persistence_subnets = var.private_persistence_subnets
+  azs                         = var.azs
 }
 
 module "spare_subnet" {
   source = "./spare-subnet"
 
   name          = "${var.name}-spare"
-  vpc_id        = "${module.vpc.vpc_id}"
-  spare_subnets = "${var.spare_subnets}"
-  azs           = "${var.azs}"
+  vpc_id        = module.vpc.vpc_id
+  spare_subnets = var.spare_subnets
+  azs           = var.azs
 }
 
 module "network_acl" {
   source = "./network-acl"
 
   name                   = "${var.name}-acl"
-  vpc_id                 = "${module.vpc.vpc_id}"
-  public_subnet_ids      = "${module.public_subnet.subnet_ids}"
-  private_app_subnet_ids = "${module.private_app_subnet.subnet_ids}"
+  vpc_id                 = module.vpc.vpc_id
+  public_subnet_ids      = module.public_subnet.subnet_ids
+  private_app_subnet_ids = module.private_app_subnet.subnet_ids
 }
 
 ##### VPC-PEERING
 module "vpc-peering" {
   source = "./vpc-peering"
   name   = "${var.name}-vpc-peering"
 
-  root_vpc_id          = "${module.vpc.vpc_id}"
-  root_vpc_cidr        = "${module.vpc.vpc_cidr}"
-  root_route_table_ids = "${module.private_app_subnet.route_table_ids}"
+  root_vpc_id          = module.vpc.vpc_id
+  root_vpc_cidr        = module.vpc.vpc_cidr
+  root_route_table_ids = module.private_app_subnet.route_table_ids
 
   # workaround: using number of availability_zones for the number of routes to be added in the route table
   # https://github.com/hashicorp/terraform/issues/3888
-  root_route_table_ids_count = "${length(var.azs)}"
+  root_route_table_ids_count = length(var.azs)
 
-  peer_route_table_ids = "${var.peer_private_app_route_table_ids}"
+  peer_route_table_ids = var.peer_private_app_route_table_ids
 
   # workaround: using number of availability_zones for the number of routes to be added in the route table
   # https://github.com/hashicorp/terraform/issues/3888
-  peer_route_table_ids_count = "${length(var.azs)}"
+  peer_route_table_ids_count = length(var.azs)
 
-  peer_owner_id = "${var.peer_owner_id}"
-  peer_vpc_id   = "${var.peer_vpc_id}"
-  peer_vpc_cidr = "${var.peer_vpc_cidr}"
+  peer_owner_id = var.peer_owner_id
+  peer_vpc_id   = var.peer_vpc_id
+  peer_vpc_cidr = var.peer_vpc_cidr
 }
 
 module "bastion-host" {
   name                        = "${var.name}-bastion-host"
   source                      = "./bastion"
   instance_type               = "t2.nano"
-  keypair                     = "${var.bastion_host_keypair}"
-  allow_ssh_cidrs             = "${var.bastion_host_allow_ssh_cidrs}"
-  ami                         = "${var.bastion_host_ami_id}"
-  region                      = "${var.aws_region}"
+  keypair                     = var.bastion_host_keypair
+  allow_ssh_cidrs             = var.bastion_host_allow_ssh_cidrs
+  ami                         = var.bastion_host_ami_id
+  region                      = var.aws_region
   s3_bucket_uri               = "s3://${var.config_bucket_name}/keypairs"
-  s3_bucket_arn               = "${var.config_bucket_arn}"
-  vpc_id                      = "${module.vpc.vpc_id}"
-  subnet_ids                  = "${module.public_subnet.subnet_ids}"
+  s3_bucket_arn               = var.config_bucket_arn
+  vpc_id                      = module.vpc.vpc_id
+  subnet_ids                  = module.public_subnet.subnet_ids
   keys_update_frequency       = "5,20,35,50 * * * *"
   additional_user_data_script = "date"
 }
@@ -186,40 +186,40 @@ module "bastion-host" {
 ######################
 # VPC
 output "vpc_id" {
-  value = "${module.vpc.vpc_id}"
+  value = module.vpc.vpc_id
 }
 
 output "vpc_cidr" {
-  value = "${module.vpc.vpc_cidr}"
+  value = module.vpc.vpc_cidr
 }
 
 # Subnets
 output "public_subnet_ids" {
-  value = "${module.public_subnet.subnet_ids}"
+  value = module.public_subnet.subnet_ids
 }
 
 output "private_app_subnet_ids" {
-  value = "${module.private_app_subnet.subnet_ids}"
+  value = module.private_app_subnet.subnet_ids
 }
 
 output "private_persistence_subnet_ids" {
-  value = "${module.private_persistence_subnet.subnet_ids}"
+  value = module.private_persistence_subnet.subnet_ids
 }
 
 # Route Tables
 output "private_app_route_table_ids" {
-  value = "${module.private_app_subnet.route_table_ids}"
+  value = module.private_app_subnet.route_table_ids
 }
 
 output "public_route_table_ids" {
-  value = "${module.public_subnet.route_table_ids}"
+  value = module.public_subnet.route_table_ids
 }
 
 # NAT
 output "nat_gateway_ids" {
-  value = "${module.nat.nat_gateway_ids}"
+  value = module.nat.nat_gateway_ids
 }
 
 output "nat_public_ip" {
-  value = "${module.nat.public_ip}"
+  value = module.nat.public_ip
 }