DPE-4933 Avoid early calls to unit_initialized (#481)

* ensure unit_initialized can be called

* restarts must be waited more

Author: paulomach

src/charm.py

@@ -445,7 +445,8 @@ def _restart(self, event: EventBase) -> None:
         self.unit.status = MaintenanceStatus("restarting MySQL")
         container = self.unit.get_container(CONTAINER_NAME)
         if container.can_connect():
-            container.restart(MYSQLD_SAFE_SERVICE)
+            logger.debug("Restarting mysqld")
+            container.pebble.restart_services([MYSQLD_SAFE_SERVICE], timeout=3600)
             sleep(10)
             self._on_update_status(None)
 

src/log_rotate_manager.py

@@ -12,6 +12,8 @@
 from ops.framework import Object
 from ops.model import ActiveStatus
 
+from constants import CONTAINER_NAME
+
 if typing.TYPE_CHECKING:
     from charm import MySQLOperatorCharm
 
@@ -31,9 +33,11 @@ def __init__(self, charm: "MySQLOperatorCharm"):
 
     def start_log_rotate_manager(self):
         """Forks off a process that periodically dispatch a custom event to rotate logs."""
+        container = self.charm.unit.get_container(CONTAINER_NAME)
         if (
             not isinstance(self.charm.unit.status, ActiveStatus)
             or self.charm.peers is None
+            or not container.can_connect()
             or not self.charm.unit_initialized
         ):
             return

src/relations/mysql.py

@@ -136,14 +136,14 @@ def _update_status(self, _) -> None:
         if not (relation_data := self.charm.app_peer_data.get(MYSQL_RELATION_DATA_KEY)):
             return
 
-        if not self.charm.unit_initialized:
-            # Skip update status for uninitialized unit
-            return
-
         container = self.charm.unit.get_container(CONTAINER_NAME)
         if not container.can_connect():
             return
 
+        if not self.charm.unit_initialized:
+            # Skip update status for uninitialized unit
+            return
+
         if not self.charm.unit.is_leader():
             return
 

src/relations/mysql_root.py

@@ -12,7 +12,7 @@
 from ops.framework import Object
 from ops.model import ActiveStatus, BlockedStatus
 
-from constants import LEGACY_MYSQL_ROOT, PASSWORD_LENGTH, ROOT_PASSWORD_KEY
+from constants import CONTAINER_NAME, LEGACY_MYSQL_ROOT, PASSWORD_LENGTH, ROOT_PASSWORD_KEY
 from mysql_k8s_helpers import (
     MySQLCreateDatabaseError,
     MySQLCreateUserError,
@@ -152,6 +152,11 @@ def _on_mysql_root_relation_created(self, event: RelationCreatedEvent) -> None:
         if not self.charm.unit.is_leader():
             return
 
+        container = self.charm.unit.get_container(CONTAINER_NAME)
+        if not container.can_connect():
+            event.defer()
+            return
+
         # Wait until on-config-changed event is executed
         # (wait for root password to have been set) or wait until the unit is initialized
         if not (self.charm._is_peer_data_set and self.charm.unit_initialized):