nxos_facts: Don't fail if faninfo isn't reported (#66866)

changelogs/fragments/66866_nxos_fan_facts.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+- "nxos_facts: Don't throw an error if faninfo is not reported."

lib/ansible/module_utils/network/nxos/facts/legacy/base.py

@@ -622,13 +622,19 @@ class Legacy(FactsBase):
 
     def parse_structured_fan_info(self, data):
         objects = list()
-        if data.get('fandetails'):
-            data = data['fandetails']['TABLE_faninfo']['ROW_faninfo']
-        elif data.get('fandetails_3k'):
-            data = data['fandetails_3k']['TABLE_faninfo']['ROW_faninfo']
-        else:
-            return objects
-        objects = list(self.transform_iterable(data, self.FAN_MAP))
+
+        for key in ("fandetails", "fandetails_3k"):
+            if data.get(key):
+                try:
+                    data = data[key]['TABLE_faninfo']['ROW_faninfo']
+                except KeyError:
+                    # Some virtual images don't actually report faninfo. In this case, move on and
+                    # just return an empty list.
+                    pass
+                else:
+                    objects = list(self.transform_iterable(data, self.FAN_MAP))
+                break
+
         return objects
 
     def parse_structured_power_supply_info(self, data):