add noop plugin

- This change adds a noop plugin
  for use with backends that auto connect
  to VIFs.

Change-Id: I4317ac2294526863d88be16ac54ecafc85ca9e1b

doc/source/index.rst

@@ -25,8 +25,9 @@ Usage Guide
    user/usage
    user/vif-types
    user/host-info
-   user/plugins/ovs
    user/plugins/linux-bridge
+   user/plugins/noop
+   user/plugins/ovs
 
 Reference
 ---------

doc/source/user/plugins/linux-bridge.rst

@@ -3,8 +3,8 @@ Linux Bridge
 ============
 
 The Linux Bridge plugin, ``vif_plug_linux_bridge``, is an `os-vif` VIF plugin
-for the Linux Bridge network backend. It is one of two plugins provided as part
-of `os-vif` itself, the other being :doc:`ovs`.
+for the Linux Bridge network backend. It is one of three plugins provided as part
+of `os-vif` itself, the others being :doc:`ovs` and :doc:`noop`.
 
 Supported VIF Types
 ===================

doc/source/user/plugins/noop.rst

@@ -0,0 +1,23 @@
+=====
+no-op
+=====
+
+The no-op plugin, ``vif_plug_noop``, is an `os-vif` VIF plugin
+for use with network backends that do not require pluging of network interfaces.
+It is one of three plugins provided as part of `os-vif` itself, the others
+being :doc:`ovs` and  :doc:`linux-bridge`.
+
+Supported VIF Types
+===================
+
+The no-op plugin provides support for the following VIF types:
+
+`VIFVHostUser`
+
+  Configuration where a guest exposes a UNIX socket for its control plane. This
+  configuration is used with a userspace dataplane such as vpp or snabb switch.
+
+  Refer to :ref:`vif-vhostuser` for more information.
+
+For information on the VIF type objects, refer to :doc:`/user/vif-types`. Note
+that only the above VIF types are supported by this plugin.

doc/source/user/plugins/ovs.rst

@@ -3,8 +3,8 @@ Open vSwitch
 ============
 
 The Open vSwitch plugin, `vif_plug_ovs`, is an `os-vif` VIF plugin for the Open
-vSwitch network backend. It is one of two plugins provided as part of `os-vif`
-itself, the other being :doc:`linux-bridge`.
+vSwitch network backend. It is one of three plugins provided as part of `os-vif`
+itself, the others being :doc:`linux-bridge` and :doc:`noop`.
 
 Supported VIF Types
 -------------------

os_vif/tests/unit/test_os_vif.py

@@ -14,8 +14,6 @@ import mock
 from oslo_config import cfg
 from stevedore import extension
 
-from vif_plug_linux_bridge import constants as lb_constants
-
 import os_vif
 from os_vif import exception
 from os_vif import objects
@@ -138,22 +136,28 @@ class TestOSVIF(base.TestCase):
     def test_host_info_all(self):
         os_vif.initialize()
         info = os_vif.host_info()
+        # NOTE(sean-k-mooney): as out of tree plugins could be
+        # visable in path assert only at at least all the in
+        # intree plugins are loaded instead of an exact match.
+        self.assertTrue(len(info.plugin_info) >= 3)
 
-        self.assertEqual(len(info.plugin_info), 2)
+        plugins = {p.plugin_name: p for p in info.plugin_info}
+        in_tree_plugin_names = ("linux_bridge", "ovs", "noop")
+        self.assertTrue(all(name in plugins for name in in_tree_plugin_names))
+        lb = plugins["linux_bridge"]
+        self.assertTrue(any("VIFBridge" == vif.vif_object_name
+                            for vif in lb.vif_info))
 
-        self.assertEqual(info.plugin_info[0].plugin_name,
-                         lb_constants.PLUGIN_NAME)
-        vif_info = info.plugin_info[0].vif_info
-        self.assertEqual(len(vif_info), 1)
-        self.assertEqual(vif_info[0].vif_object_name, "VIFBridge")
+        ovs = plugins["ovs"]
+        self.assertTrue(len(ovs.vif_info) >= 4)
+        vif_names = (vif.vif_object_name for vif in ovs.vif_info)
+        ovs_vifs = ("VIFBridge", "VIFOpenVSwitch",
+                    "VIFVHostUser", "VIFHostDevice")
+        self.assertTrue(all(name in ovs_vifs for name in vif_names))
 
-        self.assertEqual(info.plugin_info[1].plugin_name, "ovs")
-        vif_info = info.plugin_info[1].vif_info
-        self.assertEqual(len(vif_info), 4)
-        self.assertEqual(vif_info[0].vif_object_name, "VIFBridge")
-        self.assertEqual(vif_info[1].vif_object_name, "VIFOpenVSwitch")
-        self.assertEqual(vif_info[2].vif_object_name, "VIFVHostUser")
-        self.assertEqual(vif_info[3].vif_object_name, "VIFHostDevice")
+        noop = plugins["noop"]
+        self.assertTrue(any("VIFVHostUser" == vif.vif_object_name
+                            for vif in noop.vif_info))
 
     def test_host_info_filtered(self):
         os_vif.initialize()

releasenotes/notes/add-no-op-plugin-763a6703e7328a24.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    A new VIF plugin, ``vif_plug_noop``, has been added which can be used with
+    network backends that do not require any action to be performed when a
+    network interface is plugged. This plugin allow for use of, for example,
+    the generic vhost user VIF type without OVS.

setup.cfg

@@ -60,3 +60,4 @@ output_file = os_vif/locale/os-vif.pot
 os_vif =
     linux_bridge = vif_plug_linux_bridge.linux_bridge:LinuxBridgePlugin
     ovs = vif_plug_ovs.ovs:OvsPlugin
+    noop = vif_plug_noop.noop:NoOpPlugin

vif_plug_noop/noop.py

@@ -0,0 +1,48 @@
+# Copyright (C) 2011 Midokura KK
+# Copyright (C) 2011 Nicira, Inc
+# Copyright 2011 OpenStack Foundation
+# Copyright 2018 Intel Corporation
+# 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.
+
+from os_vif import objects
+from os_vif import plugin
+
+
+class NoOpPlugin(plugin.PluginBase):
+    """A no op plugin
+
+    The no op plugin can be used for any vif type that requires
+    no action to be performed on the backend network when a vif
+    is plugged. Currently only the VIFVHostUser VIF type is supported.
+    This pluggin allows for the use of generic vhost user without ovs.
+
+    """
+
+    def describe(self):
+        return objects.host_info.HostPluginInfo(
+            plugin_name="noop",
+            vif_info=[
+                objects.host_info.HostVIFInfo(
+                    vif_object_name=objects.vif.VIFVHostUser.__name__,
+                    min_version="1.0",
+                    max_version="1.0",
+                    supported_port_profiles=[])
+            ])
+
+    def plug(self, vif, instance_info):
+        pass
+
+    def unplug(self, vif, instance_info):
+        pass

vif_plug_noop/tests/unit/test_plugin.py

@@ -0,0 +1,37 @@
+# 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 testtools
+
+from os_vif import objects
+
+from vif_plug_noop import noop
+
+
+class PluginTest(testtools.TestCase):
+
+    def __init__(self, *args, **kwargs):
+        super(PluginTest, self).__init__(*args, **kwargs)
+        objects.register_all()
+        self.plugin = noop.NoOpPlugin.load("noop")
+
+    def test_plug_noop(self):
+        self.assertIn("plug", dir(self.plugin))
+        self.plugin.plug(None, None)
+
+    def test_unplug_noop(self):
+        self.assertIn("unplug", dir(self.plugin))
+        self.plugin.unplug(None, None)
+
+    def test_describe_noop(self):
+        self.assertIn("describe", dir(self.plugin))
+        self.assertTrue(len(self.plugin.describe().vif_info) > 0)