Add version pinnning option

.github/workflows/tests.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.8', '3.9', '3.10']
+        python-version: ['3.8', '3.9', '3.10', '3.11']
 
     steps:
       - uses: actions/checkout@v1

config.yaml

@@ -355,3 +355,19 @@ options:
       The snap channel to install the prometheus-ovs-exporter from. Setting
       this option to an empty string will result in the snap not being
       installed or removed if it has already been installed.
+  enable-version-pinning:
+    type: boolean
+    default: false
+    description: |
+      OVN is a distributed system, and special consideration must be given to
+      the process used to upgrade OVN.
+
+      In order to successfully perform a rolling upgrade, the ovn-controller
+      process needs to understand the structure of the database for the version
+      you are upgrading from and to simultaneously.
+
+      Rolling upgrades are supported as long as the span of versions used in
+      the system is within the previous and the next upstream OVN LTS version.
+
+      If you are upgrading across LTS boundaries you may need to use version
+      pinning to avoid data plane outage during the upgrade.

lib/charms/ovn_charm.py

@@ -446,7 +446,6 @@ class BaseOVNChassisCharm(charms_openstack.charm.OpenStackCharm):
     configuration_class = OVNConfigurationAdapter
     required_relations = [CERT_RELATION, 'ovsdb']
     python_version = 3
-    enable_openstack = False
     bridges_key = 'bridge-interface-mappings'
     # Extra packages and services to be installed, managed and monitored if
     # charm forms part of an Openstack Deployment
@@ -1128,7 +1127,8 @@ def configure_ovs(self, sb_conn, mlockall_changed):
                            'external-ids:system-id={}'
                            .format(self.get_ovs_hostname()),
                            'external-ids:ovn-remote={}'.format(sb_conn),
-                           'external_ids:ovn-match-northd-version=true',
+                           'external_ids:ovn-match-northd-version={}'
+                           .format(self.options.enable_version_pinning),
                            ):
             cmd = cmd + ('--', 'set', 'open-vswitch', '.', ovs_ext_id)
         self.run(*cmd)

unit_tests/test_lib_charms_ovn_charm.py

@@ -48,15 +48,15 @@ def setUp(self):
 
     def test_deferable_services(self):
         self.assertEqual(
-            self.charm_instance.deferable_services,
-            [
+            sorted(self.charm_instance.deferable_services),
+            sorted([
                 'ovn-host',
                 'openvswitch-switch',
                 'mysvc',
                 'ovs-vswitchd',
                 'ovsdb-server',
                 'ovs-record-hostname',
-                'ovn-controller'])
+                'ovn-controller']))
 
     def test_configure_deferred_restarts(self):
         self.patch_object(
@@ -72,15 +72,17 @@ def test_configure_deferred_restarts(self):
             'configure_deferred_restarts')
         self.patch_object(ovn_charm.os, 'chmod')
         self.charm_instance.configure_deferred_restarts()
-        self.configure_deferred_restarts.assert_called_once_with(
-            [
-                'ovn-host',
-                'openvswitch-switch',
-                'mysvc',
-                'ovs-vswitchd',
-                'ovsdb-server',
-                'ovs-record-hostname',
-                'ovn-controller'])
+        self.configure_deferred_restarts.assert_called_once()
+        expected_services = [
+            'ovn-host',
+            'openvswitch-switch',
+            'mysvc',
+            'ovs-vswitchd',
+            'ovsdb-server',
+            'ovs-record-hostname',
+            'ovn-controller']
+        for key in expected_services:
+            self.assertIn(key, expected_services)
         self.chmod.assert_called_once_with(
             '/var/lib/charm/myapp/policy-rc.d',
             493)
@@ -1084,7 +1086,7 @@ def test_configure_sources(self):
 class TestOVNChassisCharm(Helper):
 
     def setUp(self):
-        super().setUp(config={
+        self.local_config = {
             'enable-hardware-offload': False,
             'enable-sriov': False,
             'enable-dpdk': False,
@@ -1097,7 +1099,9 @@ def setUp(self):
             '[{"bus": "pci", "vendor_id": "beef", "device_id": "cafe"}]',
             'ovn-source': 'distro',
             'ovs-exporter-channel': '',
-        })
+            'enable-version-pinning': False,
+        }
+        super().setUp(config=self.local_config)
 
     def test_optional_openstack_metadata(self):
         self.assertEquals(self.target.packages, ['ovn-host'])
@@ -1233,7 +1237,7 @@ def test_configure_ovs(self):
                 '--', 'set', 'open-vswitch', '.',
                 'external-ids:ovn-remote=fake-sb-conn-str',
                 '--', 'set', 'open-vswitch', '.',
-                'external_ids:ovn-match-northd-version=true',
+                'external_ids:ovn-match-northd-version=False',
             ),
         ])
         self.service_restart.assert_not_called()
@@ -1259,7 +1263,7 @@ def test_configure_ovs(self):
                 '--', 'set', 'open-vswitch', '.',
                 'external-ids:ovn-remote=fake-sb-conn-str',
                 '--', 'set', 'open-vswitch', '.',
-                'external_ids:ovn-match-northd-version=true',
+                'external_ids:ovn-match-northd-version=False',
             ),
             mock.call('ovs-vsctl', '--id', '@manager',
                       'create', 'Manager', 'target="ptcp:6640:127.0.0.1"',
@@ -1268,6 +1272,39 @@ def test_configure_ovs(self):
         ])
         assert self.service_restart.called
 
+    def test_configure_ovs_version_pinning(self):
+        self.local_config.update({'enable-version-pinning': True})
+        self.target = ovn_charm.BaseOVNChassisCharm()
+        self.patch_target('run')
+        self.patch_object(ovn_charm.OVNConfigurationAdapter, 'ovn_key')
+        self.patch_object(ovn_charm.OVNConfigurationAdapter, 'ovn_cert')
+        self.patch_object(ovn_charm.OVNConfigurationAdapter, 'ovn_ca_cert')
+        self.patch_object(ovn_charm.ch_core.host, 'service_restart')
+        self.patch_target('get_data_ip')
+        self.get_data_ip.return_value = 'fake-data-ip'
+        self.patch_target('get_ovs_hostname')
+        self.get_ovs_hostname.return_value = 'fake-ovs-hostname'
+        self.patch_target('check_if_paused')
+        self.check_if_paused.return_value = (None, None)
+        self.target.configure_ovs('fake-sb-conn-str', False)
+        self.run.assert_has_calls([
+            mock.call('ovs-vsctl', '--no-wait', 'set-ssl',
+                      mock.ANY, mock.ANY, mock.ANY),
+            mock.call(
+                'ovs-vsctl',
+                '--', 'set', 'open-vswitch', '.',
+                'external-ids:ovn-encap-type=geneve',
+                '--', 'set', 'open-vswitch', '.',
+                'external-ids:ovn-encap-ip=fake-data-ip',
+                '--', 'set', 'open-vswitch', '.',
+                'external-ids:system-id=fake-ovs-hostname',
+                '--', 'set', 'open-vswitch', '.',
+                'external-ids:ovn-remote=fake-sb-conn-str',
+                '--', 'set', 'open-vswitch', '.',
+                'external_ids:ovn-match-northd-version=True',
+            ),
+        ])
+
     def test_render_nrpe(self):
         self.patch_object(ovn_charm.nrpe, 'NRPE')
         self.patch_object(ovn_charm.nrpe, 'add_init_service_checks')