Add unittests to privileged/vtysh

That's all

Signed-off-by: Lucas Alvares Gomes <lucasagomes@gmail.com>
Change-Id: I057072f8215af48b13835bee321298177a469057

ovn_bgp_agent/tests/unit/privileged/test_vtysh.py

@@ -0,0 +1,65 @@
+# Copyright 2022 Red Hat, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import imp
+from unittest import mock
+
+from oslo_concurrency import processutils
+
+from ovn_bgp_agent import constants
+from ovn_bgp_agent.privileged import vtysh
+from ovn_bgp_agent.tests import base as test_base
+
+# Mock the privsep decorator and reload the module
+mock.patch('ovn_bgp_agent.privileged.vtysh_cmd.entrypoint',
+           lambda x: x).start()
+imp.reload(vtysh)
+
+
+class FakeException(Exception):
+    stderr = ''
+
+
+class TestPrivilegedVtysh(test_base.TestCase):
+
+    def setUp(self):
+        super(TestPrivilegedVtysh, self).setUp()
+        # Mock pyroute2.NDB context manager object
+        self.mock_exc = mock.patch.object(processutils, 'execute').start()
+
+    def test_run_vtysh_config(self):
+        vtysh.run_vtysh_config('/fake/frr.config')
+        self.mock_exc.assert_called_once_with(
+            '/usr/bin/vtysh', '--vty_socket', constants.FRR_SOCKET_PATH,
+            '-c', 'copy /fake/frr.config running-config')
+
+    def test_run_vtysh_config_exception(self):
+        self.mock_exc.side_effect = FakeException()
+        self.assertRaises(
+            FakeException,
+            vtysh.run_vtysh_config, '/fake/frr.config')
+
+    def test_run_vtysh_command(self):
+        cmd = 'show ip bgp summary json'
+        vtysh.run_vtysh_command(cmd)
+        self.mock_exc.assert_called_once_with(
+            '/usr/bin/vtysh', '--vty_socket', constants.FRR_SOCKET_PATH,
+            '-c', cmd)
+
+    def test_run_vtysh_command_exception(self):
+        self.mock_exc.side_effect = FakeException()
+        self.assertRaises(
+            FakeException,
+            vtysh.run_vtysh_command, 'show ip bgp summary json')