public subnets also need tagging for ELB subnet discovery

main.tf

@@ -59,9 +59,7 @@ resource "aws_subnet" "public" {
   count                   = "${length(var.public_subnets)}"
   map_public_ip_on_launch = true
 
-  tags {
-    Name = "${var.name}.public.${element(var.availability_zones, count.index)}"
-  }
+  tags = "${zipmap(compact(split(",", var.enable_eks_support == "false" ? "Name" : "Name,kubernetes.io/cluster/${var.eks_cluster_name}")), compact(split(",", var.enable_eks_support == "false" ? "${var.name}.public.${element(var.availability_zones, count.index)}" : "${var.name}.public.${element(var.availability_zones, count.index)},shared")))}"
 }
 
 resource "aws_subnet" "private" {