console: add serial console module

Adds new module console/serial.py to handle configuration
and TCP ports management for the feature serial-ports.

Co-Authored-By: Vladan Popovic <vpopovic@redhat.com>
Co-Authored-By: Ian Wells <iawells@cisco.com>
Co-Authored-By: Sushma Korati <sushma_korati@persistent.co.in>

DocImpact: new group of option 'serial_console'
Partial-Implements: blueprint serial-ports
Change-Id: Icb7f3569a29a5fab9aaa3a2d441f5fe4e5b55b9f

1 files changed, 137 insertions, 0 deletions

diff --git a/nova/tests/console/test_serial.py b/nova/tests/console/test_serial.py
new file mode 100644
index 0000000000..ebdc52dafa
--- /dev/null
+++ b/nova/tests/console/test_serial.py
@@ -0,0 +1,137 @@
+# 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.
+
+"""Tests for Serial Console."""
+
+import socket
+
+import mock
+import six.moves
+
+from nova.console import serial
+from nova import exception
+from nova import test
+
+
+class SerialTestCase(test.TestCase):
+    def setUp(self):
+        super(SerialTestCase, self).setUp()
+        serial.ALLOCATED_PORTS = set()
+
+    def test_get_port_range(self):
+        start, stop = serial._get_port_range()
+        self.assertEqual(10000, start)
+        self.assertEqual(20000, stop)
+
+    def test_get_port_range_customized(self):
+        self.flags(port_range='30000:40000', group='serial_console')
+        start, stop = serial._get_port_range()
+        self.assertEqual(30000, start)
+        self.assertEqual(40000, stop)
+
+    def test_get_port_range_bad_range(self):
+        self.flags(port_range='40000:30000', group='serial_console')
+        start, stop = serial._get_port_range()
+        self.assertEqual(10000, start)
+        self.assertEqual(20000, stop)
+
+    def test_get_port_range_not_numeric(self):
+        self.flags(port_range='xxx:yyy', group='serial_console')
+        start, stop = serial._get_port_range()
+        self.assertEqual(10000, start)
+        self.assertEqual(20000, stop)
+
+    def test_get_port_range_invalid_syntax(self):
+        self.flags(port_range='10:20:30', group='serial_console')
+        start, stop = serial._get_port_range()
+        self.assertEqual(10000, start)
+        self.assertEqual(20000, stop)
+
+    @mock.patch('socket.socket')
+    def test_verify_port(self, fake_socket):
+        s = mock.MagicMock()
+        fake_socket.return_value = s
+
+        serial._verify_port('127.0.0.1', 10)
+
+        s.bind.assert_called_once_with(('127.0.0.1', 10))
+
+    @mock.patch('socket.socket')
+    def test_verify_port_in_use(self, fake_socket):
+        s = mock.MagicMock()
+        s.bind.side_effect = socket.error()
+        fake_socket.return_value = s
+
+        self.assertRaises(
+            exception.SocketPortInUseException,
+            serial._verify_port, '127.0.0.1', 10)
+
+        s.bind.assert_called_once_with(('127.0.0.1', 10))
+
+    @mock.patch('nova.console.serial._verify_port', lambda x, y: None)
+    def test_acquire_port(self):
+        start, stop = 15, 20
+        self.flags(
+            port_range='%d:%d' % (start, stop),
+            group='serial_console')
+
+        for port in six.moves.range(start, stop):
+            self.assertEqual(port, serial.acquire_port('127.0.0.1'))
+
+        for port in six.moves.range(start, stop):
+            self.assertEqual(port, serial.acquire_port('127.0.0.2'))
+
+        self.assertTrue(10, len(serial.ALLOCATED_PORTS))
+
+    @mock.patch('nova.console.serial._verify_port')
+    def test_acquire_port_in_use(self, fake_verify_port):
+        def port_10000_already_used(host, port):
+            if port == 10000 and host == '127.0.0.1':
+                raise exception.SocketPortInUseException(
+                    port=port,
+                    host=host,
+                    error="already in use")
+        fake_verify_port.side_effect = port_10000_already_used
+
+        self.assertEqual(10001, serial.acquire_port('127.0.0.1'))
+        self.assertEqual(10000, serial.acquire_port('127.0.0.2'))
+
+        self.assertNotIn(('127.0.0.1', 10000), serial.ALLOCATED_PORTS)
+        self.assertIn(('127.0.0.1', 10001), serial.ALLOCATED_PORTS)
+        self.assertIn(('127.0.0.2', 10000), serial.ALLOCATED_PORTS)
+
+    @mock.patch('nova.console.serial._verify_port')
+    def test_acquire_port_not_ble_to_bind_at_any_port(self, fake_verify_port):
+        start, stop = 15, 20
+        self.flags(
+            port_range='%d:%d' % (start, stop),
+            group='serial_console')
+
+        fake_verify_port.side_effect = (
+            exception.SocketPortRangeExhaustedException(host='127.0.0.1'))
+
+        self.assertRaises(
+            exception.SocketPortRangeExhaustedException,
+            serial.acquire_port, '127.0.0.1')
+
+    def test_release_port(self):
+        serial.ALLOCATED_PORTS.add(('127.0.0.1', 100))
+        serial.ALLOCATED_PORTS.add(('127.0.0.2', 100))
+        self.assertEqual(2, len(serial.ALLOCATED_PORTS))
+
+        serial.release_port('127.0.0.1', 100)
+        self.assertEqual(1, len(serial.ALLOCATED_PORTS))
+
+        serial.release_port('127.0.0.2', 100)
+        self.assertEqual(0, len(serial.ALLOCATED_PORTS))