fix: report a better error in validate-interfaces

When validate-interfaces runs if there is no interfaces key then we
would just have a KeyError exception that would be logged to the node.
This provides a clearer message back as to why this happened.

Change-Id: I307848a9a1733ecff534ae37541e59465b4e96b7
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
(cherry picked from commit d56a70e8ab)

ironic/drivers/modules/inspector/hooks/validate_interfaces.py

@@ -49,6 +49,11 @@ def get_interfaces(node, inventory):
     result = {}
     pxe_mac = get_pxe_mac(inventory)
 
+    if 'interfaces' not in inventory:
+        raise exception.InvalidNodeInventory(
+            node=node.uuid,
+            reason=_('no interfaces present in inventory'))
+
     for iface in inventory['interfaces']:
         name = iface.get('name')
         mac = iface.get('mac_address')

releasenotes/notes/validate-interfaces-hook-49d7d6c57929a8cd.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Report a better error message than a KeyError when there are no interfaces
+    in the inspection data when running the validate-interfaces inspection hook.