Make it a proper neutron-api plugin

This removes the need for a special neutron-api fork. Validated that the
content of /etc/neutron/ remained equivalent after this change.

Func-Test-PR: https://github.com/openstack-charmers/zaza-openstack-tests/pull/371
Change-Id: If17aeca06ef71310b1b918a1fa9a555a636b03f8

.zuul.yaml

@@ -1,6 +1,4 @@
 - project:
-    # NOTE(lourot): templates are defined in
-    # https://opendev.org/openstack/openstack-zuul-jobs
     templates:
-      - openstack-python3-ussuri-jobs
+      - openstack-python3-charm-jobs
       - openstack-cover-jobs

src/config.yaml

@@ -38,7 +38,3 @@ options:
     type: string
     description: |
       Name of the OpenStack region.
-  service-plugins:
-    default: router,firewall,metering,neutron_lbaas.services.loadbalancer.plugin.LoadBalancerPluginv2
-    type: string
-    description: Override of Neutron-API service plugins setting.

src/lib/charm/openstack/neutron_arista.py

@@ -1,26 +1,16 @@
 #!/usr/bin/env python
-from collections import OrderedDict
 from charmhelpers.core.hookenv import (
     config,
     log
 )
 import charms_openstack.charm
 
-from charmhelpers.contrib.openstack import (
-    context,
-    templating,
-)
 from charmhelpers.fetch import (
     apt_install,
     apt_update,
     filter_installed_packages,
     add_source,
 )
-from charmhelpers.contrib.openstack.utils import os_release
-
-
-ML2_CONFIG = '/etc/neutron/plugins/ml2/ml2_conf_arista.ini'
-TEMPLATES = 'templates/'
 
 
 class NeutronAristaCharm(charms_openstack.charm.OpenStackCharm):
@@ -41,33 +31,3 @@ class NeutronAristaCharm(charms_openstack.charm.OpenStackCharm):
             add_source(config('source'))
             apt_update(fatal=True)
             apt_install(self.packages[0], fatal=True)
-
-    def write_config(self):
-        configs = self.register_configs()
-        configs.write_all()
-
-    def register_configs(release=None):
-        resources = OrderedDict([
-            (ML2_CONFIG, {
-                'services': ['neutron-server'],
-                'contexts': [AristaMl2Context(), ]
-            }),
-        ])
-        release = os_release('neutron-common')
-        configs = templating.OSConfigRenderer(templates_dir=TEMPLATES,
-                                              openstack_release=release)
-        for cfg, rscs in resources.items():
-            configs.register(cfg, rscs['contexts'])
-        return configs
-
-
-class AristaMl2Context(context.OSContextGenerator):
-
-    def __call__(self):
-        ctxt = {'eapi_host': config('eapi-host'),
-                'eapi_username': config('eapi-username'),
-                'eapi_password': config('eapi-password'),
-                'region_name': config('region-name'),
-                'api_type': config('api-type'),
-                'arista_version': config('arista-version')}
-        return ctxt

src/reactive/neutron_arista_handlers.py

@@ -16,17 +16,13 @@ import charms.reactive as reactive
 
 from charmhelpers.core.hookenv import (
     config,
-)
-
-from charmhelpers.core.host import (
-    service_restart,
+    log,
 )
 
 from charms_openstack.charm import (
     provide_charm_instance,
     use_defaults,
 )
-import charm.openstack.neutron_arista as arista  # noqa
 
 
 use_defaults('update-status')
@@ -40,33 +36,45 @@ def install_arista():
     reactive.set_state('arista-package.installed')
 
 
-@reactive.when('neutron-plugin-api-subordinate.connected')
-def configure_principle(api_principle):
-    inject_config = {
-        'neutron-api': {
-            '/etc/neutron/neutron.conf': {
-                'sections': {
-                    'DEFAULT': [
-                    ],
-                }
-            }
-        }
-    }
-    with provide_charm_instance() as charm_class:
-        charm_class.write_config()
-    api_principle.configure_plugin(
-        neutron_plugin='arista',
-        core_plugin='neutron.plugins.ml2.plugin.Ml2Plugin',
-        neutron_plugin_config='/etc/neutron/plugins/ml2/ml2_conf.ini \
-        --config-file=/etc/neutron/plugins/ml2/ml2_conf_arista.ini',
-        service_plugins=config('service-plugins'),
-        subordinate_configuration=inject_config)
-
-
 @reactive.when_any('config.changed.eapi-host',
                    'config.changed.eapi-username',
                    'config.changed.eapi-password',
+                   'config.changed.region-name',
                    'config.changed.api-type',
-                   'config.changed.region-name')
-def restart_service():
-    service_restart('neutron-server')
+                   'neutron-plugin-api-subordinate.connected')
+def configure_principle():
+    try:
+        api_principle = reactive.endpoint_from_flag(
+            'neutron-plugin-api-subordinate.connected')
+
+        mechanism_drivers = ','.join((
+            api_principle.neutron_config_data.get('mechanism_drivers', ''),
+            'arista'))
+    except AttributeError:
+        log("The principle charm isn't ready yet. "
+            "Postponing its configuration...")
+        return
+
+    log('Configuring the principle charm...')
+
+    sections = {
+        'ml2_arista': [
+            ('eapi_host', config('eapi-host')),
+            ('eapi_username', config('eapi-username')),
+            ('eapi_password', config('eapi-password')),
+            ('region_name', config('region-name')),
+            ('api_type', config('api-type')),
+        ],
+    }
+
+    api_principle.configure_plugin(
+        neutron_plugin='arista',
+        mechanism_drivers=mechanism_drivers,
+        subordinate_configuration={
+            'neutron-api': {
+                '/etc/neutron/plugins/ml2/ml2_conf.ini': {
+                    'sections': sections,
+                },
+            },
+        }
+    )

src/templates/ml2_conf_arista.ini

@@ -1,11 +0,0 @@
-###############################################################################
-# [ WARNING ]
-# Configuration file maintained by Juju. Local changes may be overwritten.
-###############################################################################
-
-[ml2_arista]
-eapi_host = {{ eapi_host }}
-eapi_username = {{ eapi_username }}
-eapi_password = {{ eapi_password }}
-region_name = {{ region_name }}
-api_type = {{ api_type }}

src/tests/bundles/bionic-queens.yaml

@@ -15,11 +15,9 @@ applications:
     num_units: 1
 
   neutron-api:
-    # Temporary fork until we refactor neutron-api-plugin-arista:
-    charm: cs:~aurelien-lourot/neutron-api-arista-test-fixture
+    charm: cs:~openstack-charmers-next/neutron-api
     num_units: 1
     options:
-      enable-arista: True
       enable-ml2-dns: False
       flat-network-providers: default
       vlan-ranges: default:1000:3000
@@ -35,7 +33,7 @@ applications:
       ipv4-ptr-zone-prefix-size:
       reverse-dns-lookup: False
       dns-domain:
-      manage-neutron-plugin-legacy-mode: True
+      manage-neutron-plugin-legacy-mode: False
 
   neutron-openvswitch:
     charm: cs:~openstack-charmers-next/neutron-openvswitch
@@ -63,7 +61,6 @@ applications:
       eapi-username: admin
       eapi-password: password123
       api-type: EAPI
-      service-plugins: router
 
   nova-compute:
     charm: cs:~openstack-charmers-next/nova-compute

src/tests/bundles/bionic-rocky.yaml

@@ -19,12 +19,10 @@ applications:
     num_units: 1
 
   neutron-api:
-    # Temporary fork until we refactor neutron-api-plugin-arista:
-    charm: cs:~aurelien-lourot/neutron-api-arista-test-fixture
+    charm: cs:~openstack-charmers-next/neutron-api
     num_units: 1
     options:
       openstack-origin: cloud:bionic-rocky
-      enable-arista: True
       enable-ml2-dns: False
       flat-network-providers: default
       vlan-ranges: default:1000:3000
@@ -40,7 +38,7 @@ applications:
       ipv4-ptr-zone-prefix-size:
       reverse-dns-lookup: False
       dns-domain:
-      manage-neutron-plugin-legacy-mode: True
+      manage-neutron-plugin-legacy-mode: False
 
   neutron-openvswitch:
     charm: cs:~openstack-charmers-next/neutron-openvswitch
@@ -69,7 +67,6 @@ applications:
       eapi-username: admin
       eapi-password: password123
       api-type: EAPI
-      service-plugins: router
 
   nova-compute:
     charm: cs:~openstack-charmers-next/nova-compute

src/tests/bundles/xenial-queens.yaml

@@ -19,12 +19,10 @@ applications:
     num_units: 1
 
   neutron-api:
-    # Temporary fork until we refactor neutron-api-plugin-arista:
-    charm: cs:~aurelien-lourot/neutron-api-arista-test-fixture
+    charm: cs:~openstack-charmers-next/neutron-api
     num_units: 1
     options:
       openstack-origin: cloud:xenial-queens
-      enable-arista: True
       enable-ml2-dns: False
       flat-network-providers: default
       vlan-ranges: default:1000:3000
@@ -40,7 +38,7 @@ applications:
       ipv4-ptr-zone-prefix-size:
       reverse-dns-lookup: False
       dns-domain:
-      manage-neutron-plugin-legacy-mode: True
+      manage-neutron-plugin-legacy-mode: False
 
   neutron-openvswitch:
     charm: cs:~openstack-charmers-next/neutron-openvswitch
@@ -69,7 +67,6 @@ applications:
       eapi-username: admin
       eapi-password: password123
       api-type: EAPI
-      service-plugins: router
 
   nova-compute:
     charm: cs:~openstack-charmers-next/nova-compute

src/tests/tests.yaml

@@ -5,8 +5,7 @@ gate_bundles:
 - xenial-queens
 - bionic-queens
 
-# NOTE(lourot): on bionic-rocky our special neutron-api fork for Arista fails
-# to start with:
+# NOTE(lourot): on bionic-rocky neutron-server fails to start with:
 # neutron.plugins.ml2.managers The following mechanism drivers were not found: set(['hyperv'])
 # Disabling for now. To be investigated.
 #- bionic-rocky

unit_tests/test_neutron_arista_handlers.py

@@ -26,17 +26,40 @@ class TestRegisteredHooks(test_utils.TestRegisteredHooks):
 
 class TestHandlers(test_utils.PatchHelper):
 
-    def _patch_provide_charm_instance(self):
-        the_charm = mock.MagicMock()
-        self.patch_object(handlers, 'provide_charm_instance',
-                          name='provide_charm_instance',
-                          new=mock.MagicMock())
-        self.provide_charm_instance().__enter__.return_value = the_charm
-        self.provide_charm_instance().__exit__.return_value = None
-        return the_charm
-
     def test_configure_principal(self):
-        the_charm = self._patch_provide_charm_instance()
+        mocked_reactive = mock.MagicMock()
+        self.patch_object(handlers, 'reactive',
+                          name='reactive',
+                          new=mocked_reactive)
         principal_charm = mock.MagicMock()
-        handlers.configure_principle(principal_charm)
-        the_charm.write_config.assert_called_once_with()
+        mocked_reactive.endpoint_from_flag.return_value = principal_charm
+        principal_charm.neutron_config_data = {
+            'mechanism_drivers': 'driver1,driver2'
+        }
+
+        mocked_config = mock.MagicMock()
+        self.patch_object(handlers, 'config',
+                          name='config',
+                          new=mocked_config)
+        mocked_config.return_value = 'my_config_value'
+
+        handlers.configure_principle()
+        principal_charm.configure_plugin.assert_called_once_with(
+            neutron_plugin='arista',
+            mechanism_drivers='driver1,driver2,arista',
+            subordinate_configuration={
+                'neutron-api': {
+                    '/etc/neutron/plugins/ml2/ml2_conf.ini': {
+                        'sections': {
+                            'ml2_arista': [
+                                ('eapi_host', 'my_config_value'),
+                                ('eapi_username', 'my_config_value'),
+                                ('eapi_password', 'my_config_value'),
+                                ('region_name', 'my_config_value'),
+                                ('api_type', 'my_config_value'),
+                            ],
+                        },
+                    },
+                },
+            }
+        )