Extend configurable variables and retrieve config data

Gate ``available`` state on remote end signalling availability.

Depends-On: I9eb5f8a6039b74288a395a584f844507448cdc23
Change-Id: I44a23549e4830d89ba3182250c40dfe395767fb0

README.md

@@ -6,25 +6,46 @@ that charm.
 
 # Usage
 
-## States
+## Flags and States
 The interface provides the `{relation-name}.connected` and
-`{relation_name}.available` states.
+`{relation_name}.available` flags and states.
+
+## neutron\_config\_data
+
+The neutron\_config\_data property allows the charm author to introspect a
+subset of the principle charm context values prior to applying the context
+provided by this relation.
+
+This enables the subordinate charm to make informed decisions about how it
+should configure Neutron based on how the deployment is configured.
+
+```python
+@reactive.when('neutron-plugin-api-subordinate.connected')
+def configure_principle():
+    api_principle = reactive.endpoint_from_flag(
+        'neutron-plugin-api-subordinate.connected')
+    if 'dns' in api_principle.neutron_config_data['extension_drivers']:
+        ...
 
 ## configure\_plugin
 
 The configure\_plugin method allows the following to be configured in the
 principle charm:
 
-* **neutron\_plugin**: Name of the plugin type eg 'ovs', 'odl' etc. This is not
+* **neutron\_plugin**: Name of the plugin type eg 'ovs', 'ovn' etc. This is not
                        currently used in the principle but should be set to
                        something representitve of the plugin type.
 * **core\_plugin**:    Value of core\_plugin to be set in neutron.conf
-* **neutron\_plugin\_config**: File containing plugin config. This config file is
+* **neutron\_plugin\_config**: File containing plugin config. This config file
-                            appended to the list of configs the neutron
+                               is appended to the list of configs the neutron
                                services read on startup.
 * **service\_plugins**: Value of service\_plugins to be set in neutron.conf
-* **subordinate\_configuration**: Config to be inserted into a configuration file
+* **subordinate\_configuration**: Config to be inserted into a configuration
-                              that the principle manages.
+                                  file that the principle manages.
+* **extension\_drivers**: Value of extension\_drivers to be set in
+                          ml2\_conf.ini
+* **neutron\_security\_groups**: Toggle whether the Neutron security group
+                                 feature should be enabled or not.
 
 Request `foo = bar` is inserted into the `DEFAULT` section of neutron.conf
 
@@ -43,11 +64,15 @@ def configure_principle(api_principle):
             }
         }
     }
+    service_plugins = ','.join((
+        api_principle.neutron_config_data.get('service_plugins', ''),
+        'networking_ovn.l3.l3_ovn.OVNL3RouterPlugin'),
+    )
     api_principle.configure_plugin(
-        neutron_plugin='odl',
+        neutron_plugin='ovn',
         core_plugin='neutron.plugins.ml2.plugin.Ml2Plugin',
         neutron_plugin_config='/etc/neutron/plugins/ml2/ml2_conf.ini',
-        service_plugins='router,firewall,lbaas,vpnaas,metering',
+        service_plugins=service_plugins,
         subordinate_configuration=inject_config)
 ```
 

provides.py

@@ -14,6 +14,7 @@ class NeutronPluginAPISubordinate(RelationBase):
     def changed(self):
         """Set connected state"""
         self.set_state('{relation_name}.connected')
+        if self.neutron_api_ready():
             self.set_state('{relation_name}.available')
 
     @hook(
@@ -23,17 +24,33 @@ class NeutronPluginAPISubordinate(RelationBase):
         self.remove_state('{relation_name}.available')
         self.remove_state('{relation_name}.connected')
 
+    @property
+    def neutron_config_data(self):
+        return json.loads(self.get_remote('neutron_config_data', "{}"))
+
+    def neutron_api_ready(self):
+        if self.get_remote('neutron-api-ready') == 'yes':
+            return True
+        return False
+
     def configure_plugin(self, neutron_plugin, core_plugin=None,
                          neutron_plugin_config=None, service_plugins=None,
-                         subordinate_configuration=None):
+                         subordinate_configuration=None,
+                         extension_drivers=None, mechanism_drivers=None,
+                         tenant_network_types=None,
+                         neutron_security_groups=None):
         """Send principle plugin information
 
-        :param neutron_plugin: str Neutron plugin name eg odl
+        :param neutron_plugin: Neutron plugin name
-        :param core_plugin: str eg neutron.plugins.ml2.plugin.Ml2Plugin
+        :type neutron_plugin: str
-        :param neutron-plugin-config: str /etc/neutron/plugins/ml2/ml2_conf.ini
+        :param core_plugin: Entry point eg neutron.plugins.ml2.plugin.Ml2Plugin
-        :param service-plugins str: Comma delimited list of service plugins eg
+        :type core_plugin: str
+        :param neutron-plugin-config: /etc/neutron/plugins/ml2/ml2_conf.ini
+        :type neutron-plugin-config: str
+        :param service-plugins: Comma delimited list of service plugins eg
                                 router,firewall,lbaas,vpnaas,metering
-        :param subordinate_configuration dict: Configuration for the principle
+        :type service-plugins: str
+        :param subordinate_configuration: Configuration for the principle
                                           to inject into a configuration
                                           file it is managing eg:
             # Add sections and tuples to insert values into neutron-server's
@@ -53,6 +70,21 @@ class NeutronPluginAPISubordinate(RelationBase):
             #         }
             #     }
             # }
+        :type subordinate_configuration:
+            Dict[str, Dict[
+                str Dict[
+                    str, List[
+                        Union[str, str]]]]]
+        :param extension_drivers: Extension drivers eg dns,port_security
+        :type extension_drivers: str
+        :param mechanism_drivers: Mechanism drivers eg openvswitch,hyperv
+        :type mechanism_drivers: str
+        :param tenant_network_types: Tenant network types eg local,gre
+                                     Note that this also configures
+                                     ``type_drivers``
+        :type tenant_network_types: str
+        :param neutron_security_groups: 'true' to enable security groups
+        :type neutron_security_groups: str
         """
         if subordinate_configuration is None:
             subordinate_configuration = {}
@@ -62,6 +94,10 @@ class NeutronPluginAPISubordinate(RelationBase):
             'core-plugin': core_plugin,
             'neutron-plugin-config': neutron_plugin_config,
             'service-plugins': service_plugins,
+            'extension-drivers': extension_drivers,
+            'mechanism-drivers': mechanism_drivers,
+            'tenant-network-types': tenant_network_types,
+            'neutron-security-groups': neutron_security_groups,
             'subordinate_configuration': json.dumps(subordinate_configuration),
         }
         conversation.set_remote(**relation_info)

unit_tests/test_provides.py

@@ -109,6 +109,12 @@ class TestNeutronPluginApiSubordinateProvides(test_utils.PatchHelper):
         conversation = mock.MagicMock()
         self.patch_target('conversation', conversation)
         self.patch_target('set_state')
+        self.patch_target('get_remote')
+        self.get_remote.return_value = None
+        self.target.changed()
+        self.set_state.assert_called_once_with('{relation_name}.connected')
+        self.set_state.reset_mock()
+        self.get_remote.return_value = 'yes'
         self.target.changed()
         self.set_state.assert_has_calls([
             mock.call('{relation_name}.connected'),
@@ -125,6 +131,18 @@ class TestNeutronPluginApiSubordinateProvides(test_utils.PatchHelper):
             mock.call('{relation_name}.connected'),
         ])
 
+    def test_neutron_api_ready(self):
+        self.patch_target('get_remote')
+        self.get_remote.return_value = 'yes'
+        self.assertTrue(self.target.neutron_api_ready())
+        self.get_remote.return_value = None
+        self.assertFalse(self.target.neutron_api_ready())
+
+    def teat_neutron_config_data(self):
+        self.patch_target('get_remote')
+        self.get_remote = json.dumps({'k': 'v'})
+        self.assertEquals(self.target.neutron_config_data, {'k': 'v'})
+
     def test_configure_plugin(self):
         conversation = mock.MagicMock()
         self.patch_target('conversation', conversation)
@@ -132,13 +150,22 @@ class TestNeutronPluginApiSubordinateProvides(test_utils.PatchHelper):
                                      'aCorePlugin',
                                      'aNeutronPluginConfig',
                                      'servicePlugins1,servicePlugin2',
-                                     {'aKey': 'aValue'})
+                                     {'aKey': 'aValue'},
+                                     'extensionDriver1,extensionDriver2',
+                                     'mechanismDriver1,mechanismDriver2',
+                                     'typeDriver1,typeDriver2',
+                                     'toggleSecurityGroups',
+                                     )
         conversation.set_remote.assert_called_once_with(
             **{
                 'core-plugin': 'aCorePlugin',
                 'neutron-plugin': 'aPlugin',
                 'neutron-plugin-config': 'aNeutronPluginConfig',
                 'service-plugins': 'servicePlugins1,servicePlugin2',
+                'extension-drivers': 'extensionDriver1,extensionDriver2',
+                'mechanism-drivers': 'mechanismDriver1,mechanismDriver2',
+                'tenant-network-types': 'typeDriver1,typeDriver2',
+                'neutron-security-groups': 'toggleSecurityGroups',
                 'subordinate_configuration': json.dumps({'aKey': 'aValue'})},
         )