Drop Windows platform support from ovsdbapp

Open vSwitch 4.0.0 removes Windows support [1], including ``python-ovs``
helpers such as ``winutils`` used by ovsdbapp's Windows IDL connection
code. Remove the ``windows`` backend, platform checks in ``connection``,
``idlutils.row_by_record()`` and ``vlog.use_python_logger()``, and
related unit tests. Document Unix-like platforms as the supported
target and add a release note for deployers.

[1]https://github.com/openvswitch/ovs/commit/965eb1f87a4d47be1d86483df7d93f7a37da4961

Closes-Bug: #2168950
Assisted-By: Composer 2.5
Signed-off-by: Rodolfo Alonso <rodolfo.ah@gmail.com>
Change-Id: I617c04c1b4fe48d4c5f9d336f1df0c68e6dd1039

README.rst

@@ -8,9 +8,11 @@ ovsdbapp
 
 A library for creating OVSDB applications
 
-The ovdsbapp library is useful for creating applications that communicate
+The ovsdbapp library is useful for creating applications that communicate
 via Open_vSwitch's OVSDB protocol (https://tools.ietf.org/html/rfc7047). It
-wraps the Python 'ovs' and adds an event loop and friendly transactions.
+wraps the Python ``ovs`` package and adds an event loop and friendly
+transactions. ovsdbapp targets Unix-like systems where Open vSwitch and
+``python-ovs`` are supported.
 
 * Free software: Apache license
 * Source: https://opendev.org/openstack/ovsdbapp/

doc/source/install/index.rst

@@ -2,6 +2,9 @@
 Installation
 ============
 
+ovsdbapp is supported on Unix-like platforms with Open vSwitch and the
+``python-ovs`` bindings. Microsoft Windows is not supported.
+
 At the command line::
 
     $ pip install ovsdbapp

ovsdbapp/backend/ovs_idl/connection.py

@@ -13,7 +13,6 @@
 #    under the License.
 
 import logging
-import os
 import queue
 import threading
 import time
@@ -24,13 +23,9 @@ from ovs.db import idl
 from ovs import poller
 
 from ovsdbapp.backend.ovs_idl import idlutils
+from ovsdbapp.backend.ovs_idl.linux import connection_utils
 from ovsdbapp import exceptions
 
-if os.name == 'nt':
-    from ovsdbapp.backend.ovs_idl.windows import connection_utils
-else:
-    from ovsdbapp.backend.ovs_idl.linux import connection_utils
-
 LOG = logging.getLogger(__name__)
 
 

ovsdbapp/backend/ovs_idl/idlutils.py

@@ -20,7 +20,6 @@ import functools
 import json
 import logging
 import os
-import sys
 import time
 import uuid
 
@@ -127,16 +126,7 @@ def row_by_record(idl_, table, record):
         # Not a UUID string, continue lookup by other means
         pass
     except KeyError as e:
-        if sys.platform != 'win32':
-            # On Windows the name of the ports is described by the OVS schema:
-            # https://tinyurl.com/zk8skhx
-            # Is a UUID. (This is due to the fact on Windows port names don't
-            # have the 16 chars length limitation as for Linux). Because of
-            # this uuid.UUID(record) will not raise a ValueError exception
-            # as it happens on Linux and will try to fetch the directly
-            # the column instead of using the lookup table. This will raise
-            # a KeyError exception on Windows.
-            raise RowNotFound(table=table, col='uuid', match=record) from e
+        raise RowNotFound(table=table, col='uuid', match=record) from e
 
     rl = _LOOKUP_TABLE.get(table, RowLookup(table, get_index_column(t), None))
     # no table means uuid only, no column means lookup table only has one row

ovsdbapp/backend/ovs_idl/vlog.py

@@ -14,18 +14,9 @@
 
 import collections
 import logging
-import sys
 
 from ovs import vlog
 
-try:
-    from eventlet import patcher
-    # If eventlet is installed and the 'thread' module is patched, we will
-    # skip setting up the python logger on Windows.
-    EVENTLET_NONBLOCKING_MODE_ENABLED = patcher.is_monkey_patched('thread')
-except ImportError:
-    EVENTLET_NONBLOCKING_MODE_ENABLED = False
-
 _LOG = logging.getLogger(__name__)
 
 # Map local log LEVELS to local LOG functions
@@ -63,17 +54,6 @@ def use_python_logger(levels=ALL_LEVELS, max_level=None):
     :param: max_level: the maximum level to log
     :type: max_level: vlog level, CRITICAL, ERROR, WARN, INFO, or DEBUG
     """
-    if sys.platform == 'win32' and EVENTLET_NONBLOCKING_MODE_ENABLED:
-        # NOTE(abalutoiu) When using oslo logging we need to keep in mind that
-        # it does not work well with native threads. We need to be careful when
-        # we call eventlet.tpool.execute, and make sure that it will not use
-        # the oslo logging, since it might cause unexpected hangs if
-        # greenthreads are used. On Windows we have to use
-        # eventlet.tpool.execute for a call to the ovs lib which will use
-        # vlog to log messages. We will skip replacing the OVS IDL logger
-        # functions on Windows to avoid unexpected hangs with oslo logging
-        return
-
     if max_level:
         levels = levels[:levels.index(max_level) + 1]
 

ovsdbapp/backend/ovs_idl/windows/connection_utils.py

@@ -1,61 +0,0 @@
-# Copyright 2017 Cloudbase Solutions Srl
-#
-#    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.
-
-from ovs import poller
-from ovs import winutils
-
-from ovsdbapp.backend.ovs_idl.common import base_connection_utils
-from ovsdbapp.backend.ovs_idl.windows import utils
-
-
-class WaitQueue(base_connection_utils.WaitQueue):
-    def init_alert_notification(self):
-        # We will use an event to get signaled when there is something in
-        # the queue. The OVS poller can wait on events on Windows.
-        # NOTE(abalutoiu) The assumption made is that the queue has
-        # length 1, otherwise we will need to have a list of events with
-        # the size of the queue.
-        self.alert_event = winutils.get_new_event(bManualReset=True,
-                                                  bInitialState=False)
-
-    def alert_notification_consume(self):
-        # Set the event object to the nonsignaled state to indicate that
-        # the queue is empty.
-        winutils.win32event.ResetEvent(self.alert_event)
-
-    def alert_notify(self):
-        # Set the event object to the signaled state to indicate that
-        # we have something in the queue.
-        winutils.win32event.SetEvent(self.alert_event)
-
-    @property
-    def alert_fileno(self):
-        return self.alert_event
-
-    def close(self):
-        pass
-
-
-def monkey_patch_poller_support():
-    # Ensure that WaitForMultipleObjects will not block other greenthreads.
-    # poller.block uses WaitForMultipleObjects on Windows
-    old_block = poller.Poller.block
-
-    def new_block(self):
-        return utils.avoid_blocking_call(old_block, self)
-
-    poller.Poller.block = new_block
-
-
-monkey_patch_poller_support()

ovsdbapp/backend/ovs_idl/windows/utils.py

@@ -1,42 +0,0 @@
-# Copyright 2017 Cloudbase Solutions Srl
-#
-#    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.
-
-
-try:
-    import eventlet
-    from eventlet import tpool
-except ImportError:
-    eventlet = None
-
-
-def avoid_blocking_call(f, *args, **kwargs):
-    """Ensure that the method "f" will not block other greenthreads.
-
-    Performs the call to the function "f" received as parameter in a
-    different thread using tpool.execute when called from a greenthread.
-    This will ensure that the function "f" will not block other greenthreads.
-    If not called from a greenthread, it will invoke the function "f" directly.
-    The function "f" will receive as parameters the arguments "args" and
-    keyword arguments "kwargs". If eventlet is not installed on the system
-    then this will call directly the function "f".
-    """
-    if eventlet is None:
-        return f(*args, **kwargs)
-
-    # Note that eventlet.getcurrent will always return a greenlet object.
-    # In case of a greenthread, the parent greenlet will always be the hub
-    # loop greenlet.
-    if eventlet.getcurrent().parent:
-        return tpool.execute(f, *args, **kwargs)
-    return f(*args, **kwargs)

ovsdbapp/tests/unit/backend/ovs_idl/test_idlutils.py

@@ -161,8 +161,7 @@ class TestIdlUtils(base.TestCase):
         obj = MockCommand("test")
         self.assertEqual("test", idlutils.db_replace_record(obj))
 
-    @mock.patch('sys.platform', 'linux2')
-    def test_row_by_record_linux(self):
+    def test_row_by_record(self):
         FAKE_RECORD = 'fake_record'
         mock_idl_ = mock.MagicMock()
         mock_table = mock.MagicMock(
@@ -174,19 +173,6 @@ class TestIdlUtils(base.TestCase):
                                      FAKE_RECORD)
         self.assertEqual(mock.sentinel.row_value, res)
 
-    @mock.patch('sys.platform', 'win32')
-    def test_row_by_record_win(self):
-        FAKE_RECORD_GUID = '7b0f349d-5524-4d36-afff-5222b9fdee8c'
-        mock_idl_ = mock.MagicMock()
-        mock_table = mock.MagicMock(
-            rows={mock.sentinel.row: mock.sentinel.row_value})
-        mock_idl_.tables = {mock.sentinel.table_name: mock_table}
-
-        res = idlutils.row_by_record(mock_idl_,
-                                     mock.sentinel.table_name,
-                                     FAKE_RECORD_GUID)
-        self.assertEqual(mock.sentinel.row_value, res)
-
     def test_index_name(self):
         expected = {
             ('one',): 'one',

releasenotes/notes/drop-windows-support-7f3a2b1c9e4d5a80.yaml

@@ -0,0 +1,7 @@
+---
+upgrade:
+  - |
+    Support for running ovsdbapp on Microsoft Windows has been removed.
+    Open vSwitch removed Windows support in version 4.0.0, including the
+    ``python-ovs`` APIs ovsdbapp relied on for Windows-specific IDL
+    connection handling. ovsdbapp now targets Unix-like systems only.