Backup glance registry configuration files on upgrade >= Stein

Glance Registry has been deprecated in Stein release.
Leftover configuration files can still be read and
configure wrong settings, breaking deployment.

Closes-Bug: 1979090
Change-Id: I54b72aef0fd49b036cf1783ef9887fa9243c93f8

hooks/glance_relations.py

@@ -35,6 +35,7 @@ from subprocess import (
 )
 
 from glance_utils import (
+    backup_deprecated_configurations,
     do_openstack_upgrade,
     migrate_database,
     register_configs,
@@ -488,6 +489,7 @@ def upgrade_charm():
     resolve_CONFIGS()
     apt_install(filter_installed_packages(determine_packages()), fatal=True)
     packages_removed = remove_old_packages()
+    backup_deprecated_configurations()
     reinstall_paste_ini(force_reinstall=packages_removed)
     configure_https()
     update_nrpe_config()

hooks/glance_utils.py

@@ -651,6 +651,22 @@ def reinstall_paste_ini(force_reinstall=False):
         db.flush()
 
 
+def backup_deprecated_configurations():
+    """Backup deprecated configurations
+
+    Do not keep deprecated configurations files as they
+    can create configuration issues.
+
+    See LP#1979090"""
+    release = os_release('glance-common')
+    cmp_release = CompareOpenStackReleases(release)
+
+    # Glance registry removed in S release
+    if cmp_release >= "stein":
+        if os.path.exists(GLANCE_REGISTRY_CONF):
+            os.rename(GLANCE_REGISTRY_CONF, GLANCE_REGISTRY_CONF + ".old")
+
+
 def is_api_ready(configs):
     return (not incomplete_relation_data(configs, REQUIRED_INTERFACES))
 

unit_tests/test_glance_relations.py

@@ -98,6 +98,7 @@ TO_PATCH = [
     'determine_packages',
     'remove_old_packages',
     'services',
+    'backup_deprecated_configurations',
     # other
     'call',
     'check_call',
@@ -571,6 +572,7 @@ class GlanceRelationTests(CharmTestCase):
         self.assertTrue(self.reinstall_paste_ini.called)
         self.assertTrue(mock_update_image_location_policy.called)
         self.assertTrue(self.remove_old_packages.called)
+        self.assertTrue(self.backup_deprecated_configurations.called)
 
     @patch.object(relations, 'update_image_location_policy')
     @patch.object(relations, 'CONFIGS')

unit_tests/test_glance_utils.py

@@ -142,6 +142,12 @@ class TestGlanceUtils(CharmTestCase):
             )
         configs.register.assert_has_calls(calls, any_order=True)
 
+    def test_register_configs_stein(self):
+        self.os_release.return_value = 'stein'
+        self.relation_ids.return_value = False
+        configs = utils.register_configs()
+        self.assertNotIn(utils.GLANCE_REGISTRY_CONF, configs.templates)
+
     def test_restart_map_rocky(self):
         self.enable_memcache.return_value = True
         self.config.side_effect = None
@@ -261,6 +267,16 @@ class TestGlanceUtils(CharmTestCase):
         configs.set_release.assert_called_with(openstack_release='rocky')
         self.assertTrue(migrate.called)
 
+    @patch('os.rename')
+    @patch('os.path.exists')
+    @patch.object(utils, 'migrate_database')
+    def test_openstack_backup_stein(self, migrate, exists, rename):
+        exists.return_value = True
+        self.os_release.return_value = 'stein'
+        utils.backup_deprecated_configurations()
+        rename.assert_called_with(utils.GLANCE_REGISTRY_CONF,
+                                  utils.GLANCE_REGISTRY_CONF + '.old')
+
     @patch.object(utils, 'migrate_database')
     def test_openstack_upgrade_not_leader(self, migrate):
         self.config.side_effect = None