From 18cff04cc585ee476af1b814d8e364d9257593fb Mon Sep 17 00:00:00 2001
From: Felipe Reyes <felipe.reyes@canonical.com>
Date: Wed, 4 May 2022 09:10:39 -0400
Subject: [PATCH] Set [DEFAULT].unknown_config_option to warning.

This change sets the configuration option
[DEFAULT].unknown_config_option to warning on upgrade-charm and on
config-changed, this allows clusters running mysql-8.0.29 with the
"name" key set to run.

This option is set to "warning" by default, although mysqlrouter set it
to "error". More details at
https://dev.mysql.com/doc/mysql-router/8.0/en/mysql-router-conf-options.html#option_mysqlrouter_unknown_config_option

Closes-Bug: #1971565
Change-Id: I9613706f1e2b573af10562fb6fbf0b9a7aedf6da
(cherry picked from commit 9563b204ad838529c17a155274f5815de595f6dc)
---
 src/lib/charm/openstack/mysql_router.py       | 16 ++++++++--
 .../test_lib_charm_openstack_mysql_router.py  | 30 ++++++++++++++++++-
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/src/lib/charm/openstack/mysql_router.py b/src/lib/charm/openstack/mysql_router.py
index d451c86..ac25161 100644
--- a/src/lib/charm/openstack/mysql_router.py
+++ b/src/lib/charm/openstack/mysql_router.py
@@ -331,13 +331,24 @@ class MySQLRouterCharm(charms_openstack.charm.OpenStackCharm):
 
     def upgrade_charm(self):
         """Custom upgrade charm function to handle special upgrade logic."""
+        config = configparser.ConfigParser()
+        config.read(self.mysqlrouter_conf)
+
+        # On upgrade set the unknown_config_option to warning (LP: #1971565)
+        if 'unknown_config_option' not in config[DEFAULT_SECTION]:
+            ch_core.hookenv.log(f'[{DEFAULT_SECTION}].unknown_config_option '
+                                f'is not present in the configuration file, '
+                                f'so setting it to "warning"')
+            config[DEFAULT_SECTION]['unknown_config_option'] = 'warning'
+            ch_core.hookenv.log("Writing {}".format(self.mysqlrouter_conf))
+            with open(self.mysqlrouter_conf, 'w') as configfile:
+                config.write(configfile)
+
         # Bug 1927981 - For mysql-innodb-clusters which were deployed with a
         # cluster name which was not 'jujuCluster', an extra section to the
         # mysqrouter.conf file was written which causes the mysql router
         # service to fail to start. Remove the extraneous section at charm
         # upgrade time.
-        config = configparser.ConfigParser()
-        config.read(self.mysqlrouter_conf)
         sections = list(filter(lambda x: x.startswith('metadata_cache'),
                                config.sections()))
         if len(sections) > 1 and 'metadata_cache:jujuCluster' in sections:
@@ -740,6 +751,7 @@ class MySQLRouterCharm(charms_openstack.charm.OpenStackCharm):
             DEFAULT_SECTION: {
                 "pid_file": self.mysqlrouter_pid_file,
                 "max_connections": str(self.options.max_connections),
+                "unknown_config_option": "warning",  # LP: #1971565
             }
         }
 
diff --git a/unit_tests/test_lib_charm_openstack_mysql_router.py b/unit_tests/test_lib_charm_openstack_mysql_router.py
index a51477f..b68a749 100644
--- a/unit_tests/test_lib_charm_openstack_mysql_router.py
+++ b/unit_tests/test_lib_charm_openstack_mysql_router.py
@@ -775,7 +775,8 @@ class TestMySQLRouterCharm(test_utils.PatchHelper):
             mysql_router.DEFAULT_SECTION: {
                 'client_ssl_mode': "PASSTHROUGH",
                 'max_connections': _config_data['max_connections'],
-                'pid_file': '/run/mysql/mysqlrouter-foobar.pid'
+                'pid_file': '/run/mysql/mysqlrouter-foobar.pid',
+                'unknown_config_option': 'warning',
             },
         }
 
@@ -837,3 +838,30 @@ class TestMySQLRouterCharm(test_utils.PatchHelper):
         mrc.upgrade_charm()
         self.assertIn('metadata_cache:foo', fake_config)
         self.assertNotIn('metadata_cache:.jujuCluster', fake_config)
+
+    def test_upgrade_charm_lp1971565(self):
+        # test fix for Bug LP#1971565
+        current_config = {
+            "DEFAULT": {"client_ssl_mode": "NONE"},
+            "metadata_cache:foo": {
+                "ttl": '5',
+                "auth_cache_ttl": '-1',
+                "auth_cache_refresh_interval": '2',
+            },
+            "metadata_cache:jujuCluster": {
+                "ttl": '5',
+            },
+        }
+        fake_config = FakeConfigParser(current_config)
+
+        self.patch_object(mysql_router.charms_openstack.charm.OpenStackCharm,
+                          'upgrade_charm')
+        self.patch_object(mysql_router.configparser, "ConfigParser",
+                          return_value=fake_config)
+
+        mrc = mysql_router.MySQLRouterCharm()
+        mrc.upgrade_charm()
+        self.assertIn('metadata_cache:foo', fake_config)
+        self.assertIn('unknown_config_option', fake_config['DEFAULT'])
+        self.assertEqual(fake_config['DEFAULT']['unknown_config_option'],
+                         'warning')