Hide interfaces for existing networks in add interface panel

circle/dashboard/views/vm.py

@@ -352,7 +352,9 @@ class VmAddInterfaceView(FormOperationMixin, VmOperationView):
     def get_form_kwargs(self):
         context = super(VmAddInterfaceView, self).get_form_kwargs()
         networks = openstack_api.neutron.network_list_for_tenant(self.request, self.request.user.tenant_id)
-        choices = ((n.id, n.name) for n in networks)
+        ports = openstack_api.neutron.port_list(self.request)
+        instance_net_ids = [p.network_id for p in ports if p.device_id == self.object.id]
+        choices = [(n.id, n.name) for n in networks if n.id not in instance_net_ids]
         context.update({
             'choices': choices
         })