Fix loading CertManager method

Currently local_cert_manager is never enabled if 'cert_manager_class'
is set to 'neutron_lbaas.common.cert_manager.local_cert_manager'.
Because due to initialization order of config parameters.
This fixes it to correct order.

Change-Id: I0b60e9034e113160ec8347da52d67c4835c90cbf

etc/neutron_lbaas.conf

@@ -68,7 +68,6 @@ service_provider=LOADBALANCER:Haproxy:neutron_lbaas.services.loadbalancer.driver
 # service_provider = LOADBALANCERV2:kemptechnologies:neutron_lbaas.drivers.kemptechnologies.driver_v2.KempLoadMasterDriver:default
 
 [certificates]
-# cert_manager_class = neutron_lbaas.common.cert_manager.barbican_cert_manager
+# cert_manager_type = barbican
 ## The following option is only valid when using neutron_lbaas.common.cert_manager.local_cert_manager
 # storage_path = /var/lib/neutron-lbaas/certificates/
-

neutron_lbaas/common/cert_manager/__init__.py

@@ -12,17 +12,15 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import importlib
-
 from oslo_config import cfg
+from stevedore import driver
 
 CONF = cfg.CONF
 
-CERT_MANAGER_DEFAULT = ('neutron_lbaas.common.cert_manager.'
-                        'barbican_cert_manager')
+CERT_MANAGER_DEFAULT = 'barbican'
 
 cert_manager_opts = [
-    cfg.StrOpt('cert_manager_class',
+    cfg.StrOpt('cert_manager_type',
                default=CERT_MANAGER_DEFAULT,
                help='Certificate Manager plugin. '
                     'Defaults to {0}.'.format(CERT_MANAGER_DEFAULT))
@@ -30,9 +28,13 @@ cert_manager_opts = [
 
 CONF.register_opts(cert_manager_opts, group='certificates')
 
-# Use CERT_MANAGER_PLUGIN.CertManager and CERT_MANAGER_PLUGIN.Cert to reference
-#   the Certificate plugin chosen via the service configuration.
-# TODO(rm_work): Investigate using Stevedore here.
-CERT_MANAGER_PLUGIN = importlib.import_module(
-    CONF.certificates.cert_manager_class
-)
+_CERT_MANAGER_PLUGIN = None
+
+
+def get_backend():
+    global _CERT_MANAGER_PLUGIN
+    if not _CERT_MANAGER_PLUGIN:
+        _CERT_MANAGER_PLUGIN = driver.DriverManager(
+            "neutron_lbaas.cert_manager.backend",
+            cfg.CONF.certificates.cert_manager_type).driver
+    return _CERT_MANAGER_PLUGIN

neutron_lbaas/drivers/radware/v2_driver.py

@@ -32,7 +32,7 @@ from neutron_lbaas.drivers.radware import base_v2_driver
 from neutron_lbaas.drivers.radware import exceptions as r_exc
 from neutron_lbaas.drivers.radware import rest_client as rest
 
-CERT_MANAGER_PLUGIN = neutron_lbaas.common.cert_manager.CERT_MANAGER_PLUGIN
+CERT_MANAGER_PLUGIN = neutron_lbaas.common.cert_manager.get_backend()
 TEMPLATE_HEADER = {'Content-Type':
                    'application/vnd.com.radware.vdirect.'
                    'template-parameters+json'}

neutron_lbaas/services/loadbalancer/drivers/haproxy/jinja_cfg.py

@@ -26,7 +26,7 @@ from neutron_lbaas.common.tls_utils import cert_parser
 from neutron_lbaas.services.loadbalancer import constants
 from neutron_lbaas.services.loadbalancer import data_models
 
-CERT_MANAGER_PLUGIN = cert_manager.CERT_MANAGER_PLUGIN
+CERT_MANAGER_PLUGIN = cert_manager.get_backend()
 
 PROTOCOL_MAP = {
     constants.PROTOCOL_TCP: 'tcp',

neutron_lbaas/services/loadbalancer/plugin.py

@@ -40,7 +40,7 @@ from neutron_lbaas.services.loadbalancer import agent_scheduler
 from neutron_lbaas.services.loadbalancer import constants as lb_const
 from neutron_lbaas.services.loadbalancer import data_models
 LOG = logging.getLogger(__name__)
-CERT_MANAGER_PLUGIN = neutron_lbaas.common.cert_manager.CERT_MANAGER_PLUGIN
+CERT_MANAGER_PLUGIN = neutron_lbaas.common.cert_manager.get_backend()
 
 
 def verify_lbaas_mutual_exclusion():

neutron_lbaas/tests/unit/common/cert_manager/test_cert_manager.py

@@ -0,0 +1,44 @@
+# Copyright 2015 NEC 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 oslo_config import cfg
+
+from neutron_lbaas.common import cert_manager
+from neutron_lbaas.common.cert_manager import barbican_cert_manager as bcm
+from neutron_lbaas.common.cert_manager import get_backend
+from neutron_lbaas.common.cert_manager import local_cert_manager as lcm
+from neutron_lbaas.tests import base
+
+
+class TestCertManager(base.BaseTestCase):
+
+    def setUp(self):
+        cert_manager._CERT_MANAGER_PLUGIN = None
+        super(TestCertManager, self).setUp()
+
+    def test_barbican_cert_manager(self):
+        cfg.CONF.set_override(
+            'cert_manager_type',
+            'barbican',
+            group='certificates')
+        self.assertEqual(get_backend().CertManager,
+                         bcm.CertManager)
+
+    def test_local_cert_manager(self):
+        cfg.CONF.set_override(
+            'cert_manager_type',
+            'local',
+            group='certificates')
+        self.assertEqual(get_backend().CertManager,
+                         lcm.CertManager)

requirements.txt

@@ -20,3 +20,4 @@ python-barbicanclient>=3.0.1
 pyasn1
 pyasn1-modules
 pyOpenSSL>=0.14
+stevedore>=1.5.0 # Apache-2.0

setup.cfg

@@ -51,6 +51,9 @@ pool_schedulers =
     neutron.services.loadbalancer.agent_scheduler.LeastPoolAgentScheduler = neutron_lbaas.services.loadbalancer.agent_scheduler:LeastPoolAgentScheduler
 neutron.db.alembic_migrations =
     neutron-lbaas = neutron_lbaas.db.migration:alembic_migrations
+neutron_lbaas.cert_manager.backend =
+    barbican = neutron_lbaas.common.cert_manager.barbican_cert_manager
+    local = neutron_lbaas.common.cert_manager.local_cert_manager
 
 [build_sphinx]
 all_files = 1