Convert [ml2] physical_network_mtus to DictOpt

This option accepts a dictionary value. Use the native oslo.config
implementation so that its value is parsed at config layer and explicit
error is returned to users in case an invalid value is configured.

Change-Id: I35195eea928f99ba4ae2bcdea51436d250062d47

neutron/conf/plugins/ml2/config.py

@@ -51,13 +51,13 @@ ml2_opts = [
                       'This option allows specifying a physical network MTU '
                       'value that differs from the default global_physnet_mtu '
                       'value.')),
-    cfg.ListOpt('physical_network_mtus',
-                default=[],
-                help=_("A list of mappings of physical networks to MTU "
-                       "values. The format of the mapping is "
-                       "<physnet>:<mtu val>. This mapping allows "
-                       "specifying a physical network MTU value that "
-                       "differs from the default global_physnet_mtu value.")),
+    cfg.DictOpt('physical_network_mtus',
+                default={},
+                help=_("Mappings of physical networks to MTU values. "
+                       "The format of the mapping is <physnet>:<mtu val>. "
+                       "This mapping allows specifying a physical network MTU "
+                       "value that differs from "
+                       "the default global_physnet_mtu value.")),
     cfg.StrOpt('external_network_type',
                help=_("Default network type for external networks when no "
                       "provider attributes are specified. By default it is "

neutron/plugins/ml2/drivers/helpers.py

@@ -22,7 +22,6 @@ from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.plugins.ml2 import api
 from neutron_lib.plugins import utils as p_utils
-from neutron_lib.utils import helpers
 from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_log import log
@@ -37,13 +36,7 @@ class BaseTypeDriver(api.ML2TypeDriver):
     """BaseTypeDriver for functions common to Segment and flat."""
 
     def __init__(self):
-        try:
-            self.physnet_mtus = helpers.parse_mappings(
-                cfg.CONF.ml2.physical_network_mtus, unique_values=False
-            )
-        except Exception as e:
-            LOG.error("Failed to parse physical_network_mtus: %s", e)
-            self.physnet_mtus = []
+        self.physnet_mtus = cfg.CONF.ml2.physical_network_mtus
 
     def get_mtu(self, physical_network=None):
         return p_utils.get_deployment_physnet_mtu()

neutron/tests/unit/plugins/ml2/drivers/test_type_flat.py

@@ -38,7 +38,7 @@ class FlatTypeTest(testlib_api.SqlTestCase):
                               group='ml2_type_flat')
         self.driver = type_flat.FlatTypeDriver()
         self.context = context.Context()
-        self.driver.physnet_mtus = []
+        self.driver.physnet_mtus = {}
 
     def _get_allocation(self, context, segment):
         return flat_obj.FlatAllocation.get_object(
@@ -145,23 +145,13 @@ class FlatTypeTest(testlib_api.SqlTestCase):
         self.driver.physnet_mtus = {}
         self.assertEqual(0, self.driver.get_mtu('physnet1'))
 
-    def test_parse_physical_network_mtus(self):
-        cfg.CONF.set_override(
-            'physical_network_mtus',
-            ['physnet1:1500', 'physnet2:1500', 'physnet3:9000'],
-            group='ml2')
-        driver = type_flat.FlatTypeDriver()
-        self.assertEqual('1500', driver.physnet_mtus['physnet1'])
-        self.assertEqual('1500', driver.physnet_mtus['physnet2'])
-        self.assertEqual('9000', driver.physnet_mtus['physnet3'])
-
 
 class FlatTypeDefaultTest(base.BaseTestCase):
 
     def setUp(self):
         super(FlatTypeDefaultTest, self).setUp()
         self.driver = type_flat.FlatTypeDriver()
-        self.driver.physnet_mtus = []
+        self.driver.physnet_mtus = {}
 
     def test_validate_provider_segment_default(self):
         segment = {api.NETWORK_TYPE: p_const.TYPE_FLAT,

neutron/tests/unit/plugins/ml2/drivers/test_type_vlan.py

@@ -66,7 +66,7 @@ class VlanTypeTest(testlib_api.SqlTestCase):
         self.driver = type_vlan.VlanTypeDriver()
         self.driver._sync_vlan_allocations()
         self.context = context.Context()
-        self.driver.physnet_mtus = []
+        self.driver.physnet_mtus = {}
         self.setup_coreplugin(CORE_PLUGIN)
 
     def test_parse_network_exception_handling(self):
@@ -328,7 +328,7 @@ class VlanTypeAllocationTest(testlib_api.SqlTestCase):
                               ranges,
                               group='ml2_type_vlan')
         driver = type_vlan.VlanTypeDriver()
-        driver.physnet_mtus = []
+        driver.physnet_mtus = {}
         driver._sync_vlan_allocations()
         # swap config order from DB order after sync has happened to
         # ensure config order is followed and not DB order