Merge "Implement experimental features framework"

doc/source/admin/config-experimental-framework.rst

@@ -0,0 +1,37 @@
+.. _config-experimental-framework:
+
+===============================
+Experimental features framework
+===============================
+
+Some Neutron features are not supported because the community doesn't have
+the resources and/or technical expertise to maintain them anymore. As they
+arise, the Neutron team designates these features as experimental. Deployers
+can continue using these features at their own risk, by explicitly enabling
+them in the ``experimental`` section of ``neutron.conf``.
+
+.. note::
+   Of course, the Neutron core team would love to return experimetal features
+   to the supported status, if interested parties step up to maintain them. If
+   you are interested in maintaining any of the experimental features listed
+   below, please contact the PTL shown in the
+   `Neutron project page
+   <https://governance.openstack.org/tc/reference/projects/neutron.html>`_.
+
+The following table shows the Neutron features currently designated as
+experimetal:
+
+.. table:: **Neutron Experimental features**
+
+    =========================  ===================================
+     Feature                    Option in neutron.conf to enable
+    =========================  ===================================
+     ML2 Linuxbridge driver     linuxbridge
+    =========================  ===================================
+
+This is an example of how to enable the use of an experimental feature:
+
+.. code-block:: none
+
+   [experimental]
+   linuxbridge = true

doc/source/admin/config.rst

@@ -18,6 +18,7 @@ Configuration
    config-dns-int-ext-serv
    config-dns-res
    config-dvr-ha-snat
+   config-experimental-framework
    config-fip-port-forwardings
    config-ipam
    config-ipv6

etc/oslo-config-generator/neutron.conf

@@ -5,6 +5,7 @@ wrap_width = 79
 namespace = neutron
 namespace = neutron.agent
 namespace = neutron.db
+namespace = neutron.experimental
 namespace = neutron.extensions
 namespace = nova.auth
 namespace = ironic.auth

neutron/common/experimental.py

@@ -0,0 +1,39 @@
+#    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 oslo_config import cfg
+from oslo_log import log
+
+from neutron.conf import experimental
+
+
+LOG = log.getLogger(__name__)
+
+
+CONF = cfg.CONF
+experimental.register_experimental_opts()
+
+
+def validate_experimental_enabled(feature):
+    try:
+        is_enabled = cfg.CONF.experimental[feature]
+    except cfg.NoSuchOptError:
+        LOG.error("Experimental feature '%s' doesn't exist", feature)
+        raise SystemExit(1)
+    if is_enabled:
+        LOG.warning("Feature '%s' is unsupported and is treated as "
+                    "experimental. Use at your own risk.", feature)
+    else:
+        LOG.error("Feature '%s' is experimental and has to be explicitly "
+                  "enabled in 'cfg.CONF.experimental'", feature)
+        raise SystemExit(1)

neutron/conf/experimental.py

@@ -0,0 +1,29 @@
+#    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 oslo_config import cfg
+
+from neutron._i18n import _
+
+EXPERIMENTAL_CFG_GROUP = 'experimental'
+EXPERIMENTAL_LINUXBRIDGE = 'linuxbridge'
+experimental_opts = [
+    cfg.BoolOpt(EXPERIMENTAL_LINUXBRIDGE,
+                default=False,
+                help=_('Enable execution of the experimental Linuxbridge '
+                       'agent.')),
+]
+
+
+def register_experimental_opts(cfg=cfg.CONF):
+    cfg.register_opts(experimental_opts, EXPERIMENTAL_CFG_GROUP)

neutron/opts.py

@@ -37,6 +37,7 @@ import neutron.conf.db.l3_agentschedulers_db
 import neutron.conf.db.l3_dvr_db
 import neutron.conf.db.l3_gwmode_db
 import neutron.conf.db.l3_hamode_db
+import neutron.conf.experimental
 import neutron.conf.extensions.allowedaddresspairs
 import neutron.conf.extensions.conntrack_helper
 import neutron.conf.plugins.ml2.config
@@ -361,3 +362,11 @@ def list_sriov_agent_opts():
         ('agent',
          neutron.conf.agent.agent_extensions_manager.AGENT_EXT_MANAGER_OPTS)
     ]
+
+
+def list_experimental_opts():
+    return [
+        (neutron.conf.experimental.EXPERIMENTAL_CFG_GROUP,
+         itertools.chain(neutron.conf.experimental.experimental_opts)
+         ),
+    ]

neutron/plugins/ml2/drivers/linuxbridge/mech_driver/mech_linuxbridge.py

@@ -17,6 +17,8 @@ from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants
 
 from neutron.agent import securitygroups_rpc
+from neutron.common import experimental
+from neutron.conf import experimental as c_experimental
 from neutron.plugins.ml2.drivers import mech_agent
 from neutron.services.qos.drivers.linuxbridge import driver as lb_qos_driver
 
@@ -32,6 +34,8 @@ class LinuxbridgeMechanismDriver(mech_agent.SimpleAgentMechanismDriverBase):
     """
 
     def __init__(self):
+        experimental.validate_experimental_enabled(
+            c_experimental.EXPERIMENTAL_LINUXBRIDGE)
         sg_enabled = securitygroups_rpc.is_firewall_enabled()
         vif_details = {portbindings.CAP_PORT_FILTER: sg_enabled,
                        portbindings.VIF_DETAILS_CONNECTIVITY:

neutron/tests/fullstack/resources/config.py

@@ -97,6 +97,9 @@ class NeutronConfigFixture(ConfigFixture):
             'quotas': {
                 'quota_driver': env_desc.quota_driver
             },
+            'experimental': {
+                'linuxbridge': str(env_desc.allow_experimental_linuxbridge)
+            },
         })
 
         if use_local_apipaste:

neutron/tests/fullstack/resources/environment.py

@@ -44,7 +44,8 @@ class EnvironmentDescription(object):
                  dhcp_scheduler_class=None, ml2_extension_drivers=None,
                  api_workers=1,
                  enable_traditional_dhcp=True, local_ip_ext=False,
-                 quota_driver=quota_conf.QUOTA_DB_DRIVER):
+                 quota_driver=quota_conf.QUOTA_DB_DRIVER,
+                 allow_experimental_linuxbridge=True):
         self.network_type = network_type
         self.l2_pop = l2_pop
         self.qos = qos
@@ -72,6 +73,7 @@ class EnvironmentDescription(object):
         if self.local_ip_ext:
             self.service_plugins += ',local_ip'
         self.quota_driver = quota_driver
+        self.allow_experimental_linuxbridge = allow_experimental_linuxbridge
 
     @property
     def tunneling_enabled(self):

neutron/tests/unit/extensions/test_segment.py

@@ -36,6 +36,7 @@ from oslo_config import cfg
 from oslo_utils import uuidutils
 import webob.exc
 
+from neutron.conf import experimental as c_experimental
 from neutron.conf.plugins.ml2 import config as ml2_config
 from neutron.conf.plugins.ml2.drivers import driver_type
 from neutron.db import agents_db
@@ -874,6 +875,11 @@ class TestMl2HostSegmentMappingOVS(HostSegmentMappingTestCase):
 class TestMl2HostSegmentMappingLinuxBridge(TestMl2HostSegmentMappingOVS):
     _mechanism_drivers = ['linuxbridge', 'logger']
 
+    def setUp(self, plugin=None):
+        cfg.CONF.set_override(c_experimental.EXPERIMENTAL_LINUXBRIDGE, True,
+                              group=c_experimental.EXPERIMENTAL_CFG_GROUP)
+        super(TestMl2HostSegmentMappingLinuxBridge, self).setUp(plugin=plugin)
+
     def _register_agent(self, host, mappings=None, plugin=None):
         helpers.register_linuxbridge_agent(host=host,
                                            bridge_mappings=mappings,

neutron/tests/unit/plugins/ml2/drivers/linuxbridge/mech_driver/test_mech_linuxbridge.py

@@ -15,7 +15,9 @@
 
 from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants
+from oslo_config import cfg
 
+from neutron.conf import experimental as c_experimental
 from neutron.plugins.ml2.drivers.linuxbridge.mech_driver \
     import mech_linuxbridge
 from neutron.tests.unit.plugins.ml2 import _test_mech_agent as base
@@ -65,24 +67,44 @@ class LinuxbridgeMechanismBaseTestCase(base.AgentMechanismBaseTestCase):
 
 class LinuxbridgeMechanismGenericTestCase(LinuxbridgeMechanismBaseTestCase,
                                           base.AgentMechanismGenericTestCase):
-    pass
+
+    def setUp(self):
+        cfg.CONF.set_override(c_experimental.EXPERIMENTAL_LINUXBRIDGE, True,
+                              group=c_experimental.EXPERIMENTAL_CFG_GROUP)
+        super(LinuxbridgeMechanismGenericTestCase, self).setUp()
 
 
 class LinuxbridgeMechanismLocalTestCase(LinuxbridgeMechanismBaseTestCase,
                                         base.AgentMechanismLocalTestCase):
-    pass
+
+    def setUp(self):
+        cfg.CONF.set_override(c_experimental.EXPERIMENTAL_LINUXBRIDGE, True,
+                              group=c_experimental.EXPERIMENTAL_CFG_GROUP)
+        super(LinuxbridgeMechanismLocalTestCase, self).setUp()
 
 
 class LinuxbridgeMechanismFlatTestCase(LinuxbridgeMechanismBaseTestCase,
                                        base.AgentMechanismFlatTestCase):
-    pass
+
+    def setUp(self):
+        cfg.CONF.set_override(c_experimental.EXPERIMENTAL_LINUXBRIDGE, True,
+                              group=c_experimental.EXPERIMENTAL_CFG_GROUP)
+        super(LinuxbridgeMechanismFlatTestCase, self).setUp()
 
 
 class LinuxbridgeMechanismVlanTestCase(LinuxbridgeMechanismBaseTestCase,
                                        base.AgentMechanismVlanTestCase):
-    pass
+
+    def setUp(self):
+        cfg.CONF.set_override(c_experimental.EXPERIMENTAL_LINUXBRIDGE, True,
+                              group=c_experimental.EXPERIMENTAL_CFG_GROUP)
+        super(LinuxbridgeMechanismVlanTestCase, self).setUp()
 
 
 class LinuxbridgeMechanismGreTestCase(LinuxbridgeMechanismBaseTestCase,
                                       base.AgentMechanismGreTestCase):
-    pass
+
+    def setUp(self):
+        cfg.CONF.set_override(c_experimental.EXPERIMENTAL_LINUXBRIDGE, True,
+                              group=c_experimental.EXPERIMENTAL_CFG_GROUP)
+        super(LinuxbridgeMechanismGreTestCase, self).setUp()

releasenotes/notes/Experimental-features-framework-8c34291b5b0be367.yaml

@@ -0,0 +1,19 @@
+---
+prelude: >
+    Introduce the experimental features framework.
+features:
+  - |
+    Some Neutron features are not supported due to lack of resources or
+    technical expertise to maintain them. As they arise, those features will
+    be marked as experimental by the Neutron core team.
+    Deployers will be able to continue using experimental features by
+    explicitly enabling them in the 'experimental' section of neutron.conf.
+    The ML2 linuxbridge driver is the first feature to be marked as
+    experimental. To continue using it, deployers have to set to True the
+    'linuxbridge' option in the 'experimental' section of neutron.conf.
+deprecations:
+  - |
+    The ML2 linuxbridge agent has been marked as experimental due to lack
+    of resources to maintain it. To continue using it, deployers have to set
+    to True the 'linuxbridge' option in the 'experimental' section of
+    neutron.conf

setup.cfg

@@ -157,6 +157,7 @@ oslo.config.opts =
     neutron.base.agent = neutron.opts:list_base_agent_opts
     neutron.db = neutron.opts:list_db_opts
     neutron.dhcp.agent = neutron.opts:list_dhcp_agent_opts
+    neutron.experimental = neutron.opts:list_experimental_opts
     neutron.extensions = neutron.opts:list_extension_opts
     neutron.l3.agent = neutron.opts:list_l3_agent_opts
     neutron.metadata.agent = neutron.opts:list_metadata_agent_opts

zuul.d/rally.yaml

@@ -10,7 +10,7 @@
         OSPROFILER_COLLECTOR: redis
         OSPROFILER_HMAC_KEYS: "neutron-hmac-key-used-in-zuul-ci"
         Q_ML2_TENANT_NETWORK_TYPE: vxlan
-        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch,linuxbridge
+        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
         Q_AGENT: openvswitch
         KEYSTONE_ADMIN_ENDPOINT: true
       rally_task: rally-jobs/task-neutron.yaml

zuul.d/tempest-multinode.yaml

@@ -178,7 +178,7 @@
         DEFAULT_IMAGE_NAME: cirros-0.5.1-x86_64-uec
         DEFAULT_IMAGE_FILE_NAME: cirros-0.5.1-x86_64-uec.tar.gz
         Q_ML2_TENANT_NETWORK_TYPE: vxlan
-        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch,linuxbridge
+        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
         Q_AGENT: openvswitch
       devstack_plugins:
         neutron: https://opendev.org/openstack/neutron.git