Add the subnet_cidr as a required argument to the network module

contrib/terraform/openstack/kubespray.tf

@@ -3,6 +3,7 @@ module "network" {
 
   external_net    = "${var.external_net}"
   network_name    = "${var.network_name}"
+  subnet_cidr     = "${var.subnet_cidr}"
   cluster_name    = "${var.cluster_name}"
   dns_nameservers = "${var.dns_nameservers}"
 }

contrib/terraform/openstack/sample-inventory/cluster.tf

@@ -41,5 +41,6 @@ number_of_k8s_nodes_no_floating_ip = 4
 # networking
 network_name = "<network>"
 external_net = "<UUID>"
+subnet_cidr = "<cidr>"
 floatingip_pool = "<pool>"