terraform/openstack: add network_dns_domain variable (#5093)

This allows the user to optionally specify the dns_domain attribute on the
generated internal kubernetes network.

contrib/terraform/openstack/README.md

@@ -225,6 +225,7 @@ For your cluster, edit `inventory/$CLUSTER/cluster.tfvars`.
 |---------|-------------|
 |`cluster_name` | All OpenStack resources will use the Terraform variable`cluster_name` (default`example`) in their name to make it easier to track. For example the first compute resource will be named`example-kubernetes-1`. |
 |`network_name` | The name to be given to the internal network that will be generated |
+|`network_dns_domain` | (Optional) The dns_domain for the internal network that will be generated |
 |`dns_nameservers`| An array of DNS name server names to be used by hosts in the internal subnet. |
 |`floatingip_pool` | Name of the pool from which floating IPs will be allocated |
 |`external_net` | UUID of the external network that will be routed to |

contrib/terraform/openstack/kubespray.tf

@@ -5,12 +5,13 @@ provider "openstack" {
 module "network" {
   source = "./modules/network"
 
-  external_net    = "${var.external_net}"
-  network_name    = "${var.network_name}"
-  subnet_cidr     = "${var.subnet_cidr}"
-  cluster_name    = "${var.cluster_name}"
-  dns_nameservers = "${var.dns_nameservers}"
-  use_neutron     = "${var.use_neutron}"
+  external_net       = "${var.external_net}"
+  network_name       = "${var.network_name}"
+  subnet_cidr        = "${var.subnet_cidr}"
+  cluster_name       = "${var.cluster_name}"
+  dns_nameservers    = "${var.dns_nameservers}"
+  network_dns_domain = "${var.network_dns_domain}"
+  use_neutron        = "${var.use_neutron}"
 }
 
 module "ips" {

contrib/terraform/openstack/modules/network/main.tf

@@ -8,6 +8,7 @@ resource "openstack_networking_router_v2" "k8s" {
 resource "openstack_networking_network_v2" "k8s" {
   name           = "${var.network_name}"
   count          = "${var.use_neutron}"
+  dns_domain     = var.network_dns_domain != null ? "${var.network_dns_domain}" : null
   admin_state_up = "true"
 }
 

contrib/terraform/openstack/modules/network/variables.tf

@@ -2,6 +2,8 @@ variable "external_net" {}
 
 variable "network_name" {}
 
+variable "network_dns_domain" {}
+
 variable "cluster_name" {}
 
 variable "dns_nameservers" {

contrib/terraform/openstack/variables.tf

@@ -103,6 +103,12 @@ variable "network_name" {
   default     = "internal"
 }
 
+variable "network_dns_domain" {
+  description = "dns_domain for the internal network"
+  type        = "string"
+  default     = null
+}
+
 variable "use_neutron" {
   description = "Use neutron"
   default     = 1