Add check for external_network_bridge in neutron-status

In commit [1] old config options "external_network_bridge"
was removed.
This patch adds upgrade check which will warn operator
if any of their L3 agents is still using this config option.

[1] https://review.openstack.org/#/c/567369/

Closes-Bug: #1820763

Change-Id: I92b1e30e806dfd20d99716d31c518845fd296a3d

neutron/cmd/status.py

@@ -14,6 +14,7 @@
 
 from neutron_lib.utils import runtime
 from oslo_config import cfg
+from oslo_db import options as db_options
 from oslo_log import log as logging
 from oslo_upgradecheck import upgradecheck
 
@@ -53,6 +54,7 @@ def setup_conf(conf=cfg.CONF):
     neutron_conf_base.register_core_common_config_opts(conf)
     neutron_conf_service.register_service_opts(
         neutron_conf_service.SERVICE_OPTS, cfg.CONF)
+    db_options.set_defaults(conf)
     return conf
 
 

neutron/cmd/upgrade_checks/checks.py

@@ -12,17 +12,33 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from neutron_lib import constants
+from neutron_lib import context
+from neutron_lib.db import model_query
 from oslo_config import cfg
+from oslo_serialization import jsonutils
 from oslo_upgradecheck import upgradecheck
 
 from neutron._i18n import _
 from neutron.cmd.upgrade_checks import base
+from neutron.db.models import agent as agent_model
+
+
+def get_l3_agents():
+    filters = {'agent_type': [constants.AGENT_TYPE_L3]}
+    ctx = context.get_admin_context()
+    query = model_query.get_collection_query(ctx,
+                                             agent_model.Agent,
+                                             filters=filters)
+    return query.all()
 
 
 class CoreChecks(base.BaseChecks):
 
     def get_checks(self):
         return [
+            (_("External network bridge"),
+             self.external_network_bridge_check),
             (_("Worker counts configured"), self.worker_count_check)
         ]
 
@@ -40,3 +56,36 @@ class CoreChecks(base.BaseChecks):
                   "has changed. Please see release notes for the new values, "
                   "but it is strongly encouraged for deployers to manually "
                   "set the values for api_workers and rpc_workers."))
+
+    @staticmethod
+    def external_network_bridge_check(checker):
+        if not cfg.CONF.database.connection:
+            return upgradecheck.Result(
+                upgradecheck.Code.WARNING,
+                _("Database connection string is not set. Check of usage of "
+                  "'external_network_bridge' config option in L3 agents "
+                  "can't be done"))
+
+        agents_with_external_bridge = []
+        for agent in get_l3_agents():
+            config_string = agent.get('configurations')
+            if not config_string:
+                continue
+            config = jsonutils.loads(config_string)
+            if config.get("external_network_bridge"):
+                agents_with_external_bridge.append(agent.get("host"))
+
+        if agents_with_external_bridge:
+            return upgradecheck.Result(
+                upgradecheck.Code.WARNING,
+                _("L3 agents on hosts %s are still using "
+                  "'external_network_bridge' config option to provide "
+                  "gateway connectivity. This option is now removed. "
+                  "Migration of routers from those L3 agents will be "
+                  "required to connect them to external network through "
+                  "integration bridge.") % agents_with_external_bridge)
+        else:
+            return upgradecheck.Result(
+                upgradecheck.Code.SUCCESS,
+                _("L3 agents are using integration bridge to connect external "
+                  "gateways"))

neutron/tests/unit/cmd/upgrade_checks/test_checks.py

@@ -52,3 +52,30 @@ class TestChecks(base.BaseTestCase):
         cfg.CONF.set_override("rpc_workers", None)
         result = checks.CoreChecks.worker_count_check(mock.Mock())
         self.assertEqual(Code.WARNING, result.code)
+
+    def test_external_network_bridge_check_good(self):
+        agents = [
+            {'host': 'Host A', 'configurations': '{}'},
+            {'host': 'Host B',
+             'configurations': '{"external_network_bridge": ""}'}
+        ]
+        with mock.patch.object(checks, "get_l3_agents", return_value=agents):
+            result = checks.CoreChecks.external_network_bridge_check(
+                mock.Mock())
+            self.assertEqual(Code.SUCCESS, result.code)
+
+    def test_external_network_bridge_check_bad(self):
+        agents = [
+            {'host': 'Host A', 'configurations': '{}'},
+            {'host': 'Host B',
+             'configurations': '{"external_network_bridge": "br-ex"}'},
+            {'host': 'Host C',
+             'configurations': '{"external_network_bridge": ""}'}
+        ]
+        with mock.patch.object(checks, "get_l3_agents", return_value=agents):
+            result = checks.CoreChecks.external_network_bridge_check(
+                mock.Mock())
+            self.assertEqual(Code.WARNING, result.code)
+            self.assertIn('Host B', result.details)
+            self.assertNotIn('Host A', result.details)
+            self.assertNotIn('Host C', result.details)