nso_config handle data.not_found in exists for nested lists (#35267)

Recent NSO can return data.not_found error on exists when parent list
entries does not exist. Handle this and return as false.

Fixes: #35264

lib/ansible/module_utils/network/nso/nso.py

@@ -140,8 +140,16 @@ class JsonRpc(object):
 
     def exists(self, path):
         payload = {'method': 'exists', 'params': {'path': path}}
+        try:
             resp, resp_json = self._read_call(payload)
             return resp_json['result']['exists']
+        except NsoException as ex:
+            # calling exists on a sub-list when the parent list does
+            # not exists will cause data.not_found errors on recent
+            # NSO
+            if 'type' in ex.error and ex.error['type'] == 'data.not_found':
+                return False
+            raise
 
     def create(self, th, path):
         payload = {'method': 'create', 'params': {'th': th, 'path': path}}

test/units/module_utils/network/nso/test_nso.py

@@ -256,6 +256,34 @@ def get_schema_response(path):
             SCHEMA_DATA[path]))
 
 
+class TestJsonRpc(unittest.TestCase):
+    @patch('ansible.module_utils.network.nso.nso.open_url')
+    def test_exists(self, open_url_mock):
+        calls = [
+            MockResponse('new_trans', {}, 200, '{"result": {"th": 1}}'),
+            MockResponse('exists', {'path': '/exists'}, 200, '{"result": {"exists": true}}'),
+            MockResponse('exists', {'path': '/not-exists'}, 200, '{"result": {"exists": false}}')
+        ]
+        open_url_mock.side_effect = lambda *args, **kwargs: mock_call(calls, *args, **kwargs)
+        client = nso.JsonRpc('http://localhost:8080/jsonrpc')
+        self.assertEquals(True, client.exists('/exists'))
+        self.assertEquals(False, client.exists('/not-exists'))
+
+        self.assertEqual(0, len(calls))
+
+    @patch('ansible.module_utils.network.nso.nso.open_url')
+    def test_exists_data_not_found(self, open_url_mock):
+        calls = [
+            MockResponse('new_trans', {}, 200, '{"result": {"th": 1}}'),
+            MockResponse('exists', {'path': '/list{missing-parent}/list{child}'}, 200, '{"error":{"type":"data.not_found"}}')
+        ]
+        open_url_mock.side_effect = lambda *args, **kwargs: mock_call(calls, *args, **kwargs)
+        client = nso.JsonRpc('http://localhost:8080/jsonrpc')
+        self.assertEquals(False, client.exists('/list{missing-parent}/list{child}'))
+
+        self.assertEqual(0, len(calls))
+
+
 class TestValueBuilder(unittest.TestCase):
     @patch('ansible.module_utils.network.nso.nso.open_url')
     def test_identityref_leaf(self, open_url_mock):