diff --git a/devops/devops/driver/libvirt.py b/devops/devops/driver/libvirt.py
index 7da0bb579..ef165efba 100644
--- a/devops/devops/driver/libvirt.py
+++ b/devops/devops/driver/libvirt.py
@@ -347,8 +347,8 @@ class Libvirt:
                 continue
 
             self._virsh(
-                ['send-key', node.id].append(
-                    map(lambda x: str(x), key_codes)))
+                ['send-key', node.id] +
+                    map(lambda x: str(x), key_codes))
 
     def _create_disk(self, name, capacity='1', pool='default', format='qcow2'):
         self._virsh(
diff --git a/devops/devops/model.py b/devops/devops/model.py
index 9054ca62f..765447120 100644
--- a/devops/devops/model.py
+++ b/devops/devops/model.py
@@ -134,6 +134,16 @@ class Node(ManagedObject):
             return None
         return x[0]
 
+    @property
+    def ip_address_by_network(self):
+        name2ip_addresses = {}
+        for interface in self.interfaces:
+            if len(interface.ip_addresses) == 0:
+                name2ip_addresses[interface.network.name] = None
+            else:
+                name2ip_addresses[interface.network.name] = interface.ip_addresses[0]
+        return name2ip_addresses
+
     @ManagedObject.driver.setter
     def driver(self, driver):
         ManagedObject.driver.fset(self, driver)