Fix gate for enabling FQDN agent registration

If a new version of the charm is used to install a version of
OpenStack prior to Stein, do not enable the FQDN registration.

Change-Id: Ib86d6a48ee34c9efc42b4455ac669ef0cb8dc3bb
Closes-Bug: #1846781

hooks/nova_compute_context.py

@@ -786,7 +786,7 @@ class HostIPContext(context.OSContextGenerator):
             # We do want to migrate to using FQDNs so we enable this for new
             # installations.
             db = kv()
-            if db.get('install_version', 0) >= 1910:
+            if db.get('nova-compute-charm-use-fqdn', False):
                 fqdn = socket.getfqdn(host_ip)
                 if '.' in fqdn:
                     # only populate the value if getfqdn() is able to find an

hooks/nova_compute_hooks.py

@@ -62,12 +62,14 @@ from charmhelpers.fetch import (
 )
 
 from charmhelpers.contrib.openstack.utils import (
+    CompareOpenStackReleases,
     configure_installation_source,
-    openstack_upgrade_available,
     is_unit_paused_set,
+    openstack_upgrade_available,
+    os_release,
     pausable_restart_on_change as restart_on_change,
-    series_upgrade_prepare,
     series_upgrade_complete,
+    series_upgrade_prepare,
 )
 
 from charmhelpers.contrib.storage.linux.ceph import (
@@ -156,9 +158,13 @@ def install():
     apt_update()
     apt_install(determine_packages(), fatal=True)
 
-    db = kv()
-    db.set('install_version', 1910)
-    db.flush()
+    # Start migration to agent registration with FQDNs for newly installed
+    # units with OpenStack release Stein or newer.
+    release = os_release('nova-common')
+    if CompareOpenStackReleases(release) >= 'stein':
+        db = kv()
+        db.set('nova-compute-charm-use-fqdn', True)
+        db.flush()
 
 
 @hooks.hook('config-changed')

unit_tests/test_nova_compute_contexts.py

@@ -607,7 +607,8 @@ class NovaComputeContextTests(CharmTestCase):
         self.assertEqual({'host_ip': '172.24.0.79'}, host_ip())
         self.get_relation_ip.assert_called_with('cloud-compute',
                                                 cidr_network=None)
-        self.kv.return_value = FakeUnitdata(install_version=1910)
+        self.kv.return_value = FakeUnitdata(
+            **{'nova-compute-charm-use-fqdn': True})
         _getfqdn.return_value = 'some'
         host_ip = context.HostIPContext()
         self.assertEqual({'host_ip': '172.24.0.79'}, host_ip())

unit_tests/test_nova_compute_hooks.py

@@ -113,15 +113,24 @@ class NovaComputeRelationsTests(CharmTestCase):
         self.get_relation_ip.return_value = '10.0.0.50'
         self.is_container.return_value = False
 
-    def test_install_hook(self):
+    @patch.object(hooks, 'kv')
+    @patch.object(hooks, 'os_release')
+    def test_install_hook(self, _os_release, _kv):
         repo = 'cloud:precise-grizzly'
         self.test_config.set('openstack-origin', repo)
         self.determine_packages.return_value = ['foo', 'bar']
+        _os_release.return_value = 'rocky'
         hooks.install()
         self.configure_installation_source.assert_called_with(repo)
         self.assertTrue(self.apt_update.called)
         self.apt_install.assert_called_with(['foo', 'bar'], fatal=True)
         self.assertTrue(self.execd_preinstall.called)
+        _os_release.return_value = 'stein'
+        kv = MagicMock()
+        _kv.return_value = kv
+        hooks.install()
+        kv.set.assert_called_once_with('nova-compute-charm-use-fqdn', True)
+        kv.flush.assert_called_once_with()
 
     @patch.object(hooks, 'ceph_changed')
     @patch.object(hooks, 'neutron_plugin_joined')