master and agents .tf files need to use element in subnet_id

Author: jeremyvdw

aws/master.tf

@@ -161,7 +161,7 @@ resource "aws_instance" "master" {
   # We're going to launch into the same subnet as our ELB. In a production
   # environment it's more common to have a separate private subnet for
   # backend instances.
-  subnet_id = "${aws_subnet.public.*.id[count.index]}"
+  subnet_id = "${element(aws_subnet.public.*.id, count.index)}"
 
  # We run a remote provisioner on the instance after creating it.
   # In this case, we just install nginx and start it. By default,

aws/private-agent.tf

@@ -42,7 +42,7 @@ resource "aws_instance" "agent" {
   # We're going to launch into the same subnet as our ELB. In a production
   # environment it's more common to have a separate private subnet for
   # backend instances.
-  subnet_id = "${aws_subnet.private.*.id[count.index]}"
+  subnet_id = "${element(aws_subnet.private.*.id, count.index)}"
 
   # OS init script
   provisioner "file" {

aws/public-agent.tf

@@ -84,7 +84,7 @@ resource "aws_instance" "public-agent" {
   # We're going to launch into the same subnet as our ELB. In a production
   # environment it's more common to have a separate private subnet for
   # backend instances.
-  subnet_id = "${aws_subnet.public.*.id[count.index]}"
+  subnet_id = "${element(aws_subnet.public.*.id, count.index)}"
 
   # OS init script
   provisioner "file" {