state_diff: add more information to the missing_interfaces result

For netplan interfaces add the name and type. For system interfaces add
the name, type and index.

Author: daniloegea

netplan_cli/cli/state_diff.py

@@ -326,8 +326,22 @@ def _analyze_missing_interfaces(self, report: dict) -> None:
             if iface.netdef_id not in netplan_interfaces:
                 system_only.append(iface.name)
 
-        report['missing_interfaces_system'] = sorted(netplan_only)
-        report['missing_interfaces_netplan'] = sorted(system_only)
+        netplan_only = sorted(netplan_only)
+        system_only = sorted(system_only)
+
+        system_state = self.system_state.get_data()
+
+        for iface in netplan_only:
+            iface_type = self.netplan_state.netdefs.get(iface).type
+            report['missing_interfaces_system'][iface] = {
+                'type': DEVICE_TYPES.get(iface_type, 'unknown')
+            }
+
+        for iface in system_only:
+            report['missing_interfaces_netplan'][iface] = {
+                'type': system_state.get(iface).get('type', 'unknown'),
+                'index': system_state.get(iface).get('index'),
+            }
 
     def _normalize_routes(self, routes: set) -> set:
         ''' Apply some transformations to Netplan routes so their representation

tests/cli/test_state_diff.py

@@ -462,8 +462,8 @@ def test_diff_not_missing_system_interface_with_match(self):
 
         diff = NetplanDiffState(system_state, netplan_state)
         diff_data = diff.get_diff()
-        missing = diff_data.get('missing_interfaces_system', [])
-        self.assertListEqual(missing, [])
+        missing = diff_data.get('missing_interfaces_system', {})
+        self.assertDictEqual(missing, {})
 
     def test__get_comparable_interfaces_empty(self):
         res = self.diff_state._get_comparable_interfaces({})