topogen: handle JSON decode failures

Instead of raise()ing, return a empty dictionary.

diff --git a/tests/topotests/lib/topogen.py b/tests/topotests/lib/topogen.py
index 758ebcf2bfb6ed420bf552fbf59d2ef51c74dfed..ad8dd813c2a6857c2b14addb90b69c509c8c75ea 100644 (file)
--- a/tests/topotests/lib/topogen.py
+++ b/tests/topotests/lib/topogen.py
@@ -645,7 +645,11 @@ class TopoRouter(TopoGear):
         if isjson is False:
             return output
 
-        return json.loads(output)
+        try:
+            return json.loads(output)
+        except ValueError:
+            logger.warning('vtysh_cmd: failed to convert json output')
+            return {}
 
     def vtysh_multicmd(self, commands, pretty_output=True):
         """