fixed volume attach syntax

main.tf

@@ -72,8 +72,10 @@ module "create-ohpc-instance" {
     floating_ip_ohpc = module.floating-ip-address.ohpc_address
     ohpc_user =  var.ohpc_user
     ssh_private_key = var.ssh_private_key
-    vol_id = data.openstack_blockstorage_volume_v3.disk.id
-    vol_id_queue_data_vol = data.openstack_blockstorage_volume_v3.disk2.id
+    volumes = [
+      data.openstack_blockstorage_volume_v3.disk.id,
+      data.openstack_blockstorage_volume_v3.disk2.id
+    ]
 }
 
 # runs the ood-instance module - creates ood instance using variables defined above