Use 'private_dns' as hostname in inventory file (#5463)

contrib/terraform/aws/create-infrastructure.tf

@@ -150,12 +150,12 @@ data "template_file" "inventory" {
 
   vars = {
     public_ip_address_bastion = "${join("\n", formatlist("bastion ansible_host=%s", aws_instance.bastion-server.*.public_ip))}"
-    connection_strings_master = "${join("\n", formatlist("%s ansible_host=%s", aws_instance.k8s-master.*.tags.Name, aws_instance.k8s-master.*.private_ip))}"
-    connection_strings_node   = "${join("\n", formatlist("%s ansible_host=%s", aws_instance.k8s-worker.*.tags.Name, aws_instance.k8s-worker.*.private_ip))}"
-    connection_strings_etcd   = "${join("\n", formatlist("%s ansible_host=%s", aws_instance.k8s-etcd.*.tags.Name, aws_instance.k8s-etcd.*.private_ip))}"
-    list_master               = "${join("\n", aws_instance.k8s-master.*.tags.Name)}"
-    list_node                 = "${join("\n", aws_instance.k8s-worker.*.tags.Name)}"
-    list_etcd                 = "${join("\n", aws_instance.k8s-etcd.*.tags.Name)}"
+    connection_strings_master = "${join("\n", formatlist("%s ansible_host=%s", aws_instance.k8s-master.*.private_dns, aws_instance.k8s-master.*.private_ip))}"
+    connection_strings_node   = "${join("\n", formatlist("%s ansible_host=%s", aws_instance.k8s-worker.*.private_dns, aws_instance.k8s-worker.*.private_ip))}"
+    connection_strings_etcd   = "${join("\n", formatlist("%s ansible_host=%s", aws_instance.k8s-etcd.*.private_dns, aws_instance.k8s-etcd.*.private_ip))}"
+    list_master               = "${join("\n", aws_instance.k8s-master.*.private_dns)}"
+    list_node                 = "${join("\n", aws_instance.k8s-worker.*.private_dns)}"
+    list_etcd                 = "${join("\n", aws_instance.k8s-etcd.*.private_dns)}"
     elb_api_fqdn              = "apiserver_loadbalancer_domain_name=\"${module.aws-elb.aws_elb_api_fqdn}\""
   }
 }