Support router attached to different net's sn (#261)

* Support router attached to different net's sn

django-cloudlaunch/cloudlaunch/backend_plugins/base_vm_app.py

@@ -227,8 +227,15 @@ def _setup_networking(self, provider, net_id, subnet_id, placement):
                 provider, net_id, placement)
         # Make sure the subnet has Internet connectivity
         try:
-            found_routers = [router for router in provider.networking.routers
-                             if router.network_id == subnet.network_id]
+            # This will allow to re-use a router when subnets from multiple networks are attached to it
+            # xref: https://github.com/galaxyproject/cloudlaunch/pull/261
+            if provider.PROVIDER_ID == 'openstack':
+                found_routers = [router for router in provider.networking.routers
+                                 if subnet.network_id in [port.network_id for port in
+                                                          provider.os_conn.list_ports(filters={'device_id': self.id})]]
+            else:
+                found_routers = [router for router in provider.networking.routers
+                                 if router.network_id == subnet.network_id]
             # Check if the subnet's network is connected to a router
             router = None
             for r in found_routers: