[PATCH] Return None from Device._ethtool_get_driver() on failed query

[Artem Savkov]

When ethtool fails to find a driver for some reason lnst-slave fails with a
"AttributeError: 'NoneType' object has no attribute 'group'"
exception. This
should be handled gracefully.

This might happen for example on 2.6.32-431.*.el6 kernels probably due to a kernel
bug: the kernel sends a RTM_DELLINK message and right after that a RTM_NEWLINK
for the same device which triggers device.init_netlink() call and a driver
query for a missing device.

Signed-off-by: Artem Savkov <asavkov(a)redhat.com&gt;
---
 lnst/Slave/InterfaceManager.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lnst/Slave/InterfaceManager.py b/lnst/Slave/InterfaceManager.py
index 01b23e5..b014c6b 100644
--- a/lnst/Slave/InterfaceManager.py
+++ b/lnst/Slave/InterfaceManager.py
@@ -498,7 +498,7 @@ class Device(object):
             return 'loopback'
         out, _ = exec_cmd("ethtool -i %s" % self._name, False, False, False)
         match = re.search("^driver: (.*)$", out, re.MULTILINE)
-        return match.group(1)
+        return match.group(1) if match else None
 
     def get_if_data(self):
         if_data = {"devname": self._name,
-- 
2.1.0