addons: bridge: add "None" check (string) for unsupported bridge attr on some systems

Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>

diff --git a/ifupdown2/addons/bridge.py b/ifupdown2/addons/bridge.py
index e51d2b411c2afdab9d3ac468db70d6c71edb5640..9c1de18c4ead51e0dc69b313d7049adc3d1bd036 100644 (file)
--- a/ifupdown2/addons/bridge.py
+++ b/ifupdown2/addons/bridge.py
@@ -1249,7 +1249,7 @@ class bridge(moduleBase):
             old_cache_key = self._ifla_br_attributes_old_cache_key_map.get(nl_attr)
             if old_cache_key and not link_just_created:
                 cached_value = self.brctlcmd.link_cache_get([ifname, 'linkinfo', old_cache_key])
-                if not cached_value:
+                if not cached_value or cached_value == "None":
                     # the link already exists but we don't have any value
                     # cached for this attr, it probably means that the
                     # capability is not available on this system (i.e old kernel)