Terraform 0.12 (#20)

* Terraform 0.12

eks-demo/eks-workers.tf

@@ -17,18 +17,19 @@ locals {
   demo-node-userdata = <<USERDATA
 #!/bin/bash
 set -o xtrace
-/etc/eks/bootstrap.sh --apiserver-endpoint '${aws_eks_cluster.demo.endpoint}' --b64-cluster-ca '${aws_eks_cluster.demo.certificate_authority.0.data}' '${var.cluster-name}'
+/etc/eks/bootstrap.sh --apiserver-endpoint '${aws_eks_cluster.demo.endpoint}' --b64-cluster-ca '${aws_eks_cluster.demo.certificate_authority[0].data}' '${var.cluster-name}'
 USERDATA
+
 }
 
 resource "aws_launch_configuration" "demo" {
   associate_public_ip_address = true
-  iam_instance_profile        = "${aws_iam_instance_profile.demo-node.name}"
-  image_id                    = "${data.aws_ami.eks-worker.id}"
-  instance_type               = "t2.large"
-  name_prefix                 = "terraform-eks-demo"
-  security_groups             = ["${aws_security_group.demo-node.id}"]
-  user_data_base64            = "${base64encode(local.demo-node-userdata)}"
+  iam_instance_profile = aws_iam_instance_profile.demo-node.name
+  image_id = data.aws_ami.eks-worker.id
+  instance_type = "t2.large"
+  name_prefix = "terraform-eks-demo"
+  security_groups = [aws_security_group.demo-node.id]
+  user_data_base64 = base64encode(local.demo-node-userdata)
 
   lifecycle {
     create_before_destroy = true
@@ -36,22 +37,31 @@ resource "aws_launch_configuration" "demo" {
 }
 
 resource "aws_autoscaling_group" "demo" {
-  desired_capacity     = 2
-  launch_configuration = "${aws_launch_configuration.demo.id}"
-  max_size             = 2
-  min_size             = 1
-  name                 = "terraform-eks-demo"
-  vpc_zone_identifier  = ["${module.vpc.public_subnets}"]
+  desired_capacity = 2
+  launch_configuration = aws_launch_configuration.demo.id
+  max_size = 2
+  min_size = 1
+  name = "terraform-eks-demo"
+  # TF-UPGRADE-TODO: In Terraform v0.10 and earlier, it was sometimes necessary to
+  # force an interpolation expression to be interpreted as a list by wrapping it
+  # in an extra set of list brackets. That form was supported for compatibilty in
+  # v0.11, but is no longer supported in Terraform v0.12.
+  #
+  # If the expression in the following list itself returns a list, remove the
+  # brackets to avoid interpretation as a list of lists. If the expression
+  # returns a single list item then leave it as-is and remove this TODO comment.
+  vpc_zone_identifier = module.vpc.public_subnets
 
   tag {
-    key                 = "Name"
-    value               = "terraform-eks-demo"
+    key = "Name"
+    value = "terraform-eks-demo"
     propagate_at_launch = true
   }
 
   tag {
-    key                 = "kubernetes.io/cluster/${var.cluster-name}"
-    value               = "owned"
+    key = "kubernetes.io/cluster/${var.cluster-name}"
+    value = "owned"
     propagate_at_launch = true
   }
 }
+