make changes for mongos-k8s

lib/charms/mongodb/v0/config_server_interface.py

@@ -8,7 +8,9 @@
 """
 import logging
 from typing import Optional
+from charms.mongodb.v0.mongo import MongoConnection
 
+from pymongo.errors import PyMongoError
 from charms.data_platform_libs.v0.data_interfaces import (
     DatabaseProvides,
     DatabaseRequestedEvent,
@@ -185,8 +187,6 @@ def _on_relation_broken(self, event) -> None:
             logger.info("Skipping relation broken event, broken event due to scale down")
             return
 
-        self.charm.client_relations.oversee_users(departed_relation_id, event)
-
     def update_config_server_db(self, event):
         """Provides related mongos applications with new config server db."""
         if not self.pass_hook_checks(event):
@@ -314,6 +314,8 @@ def _on_relation_changed(self, event) -> None:
 
         # avoid restarting mongos when possible
         if not updated_keyfile and not updated_config and self.is_mongos_running():
+            # mongos-k8s router must update its users on start
+            self._update_k8s_users(event)
             return
 
         # mongos is not available until it is using new secrets
@@ -332,6 +334,18 @@ def _on_relation_changed(self, event) -> None:
         if self.charm.unit.is_leader():
             self.charm.mongos_initialised = True
 
+        # mongos-k8s router must update its users on start
+        self._update_k8s_users(event)
+
+    def _update_k8s_users(self, event) -> None:
+        # K8s can handle its 1:Many users after being initialized
+        try:
+            if self.substrate == Config.Substrate.K8S:
+                self.charm.client_relations.oversee_users(None, None)
+        except PyMongoError:
+            event.defer()
+            logger.debug("failed to add users on mongos-k8s router, will defer and try again.")
+
     def _on_relation_broken(self, event: RelationBrokenEvent) -> None:
         # Only relation_deparated events can check if scaling down
         if not self.charm.has_departed_run(event.relation.id):
@@ -345,6 +359,22 @@ def _on_relation_broken(self, event: RelationBrokenEvent) -> None:
             logger.info("Skipping relation broken event, broken event due to scale down")
             return
 
+        # remove all client mongos-k8s users
+        if (
+            self.charm.unit.is_leader()
+            and self.charm.client_relations.remove_all_relational_users()
+        ):
+            try:
+                self.charm.client_relations.remove_all_relational_users()
+
+                # now that the client mongos users have been removed we can remove ourself
+                with MongoConnection(self.charm.mongo_config) as mongo:
+                    mongo.drop_user(self.charm.mongo_config.username)
+            except PyMongoError:
+                logger.debug("Trouble removing router users, will defer and try again")
+                event.defer()
+                return
+
         self.charm.stop_mongos_service()
         logger.info("Stopped mongos daemon")
 
@@ -359,7 +389,7 @@ def _on_relation_broken(self, event: RelationBrokenEvent) -> None:
         if self.substrate == Config.Substrate.VM:
             self.charm.remove_connection_info()
         else:
-            self.db_initialised = False
+            self.charm.db_initialised = False
 
     # BEGIN: helper functions
     def pass_hook_checks(self, event):

lib/charms/mongodb/v1/mongodb_provider.py

@@ -16,13 +16,7 @@
 from charms.data_platform_libs.v0.data_interfaces import DatabaseProvides
 from charms.mongodb.v0.mongo import MongoConfiguration, MongoConnection
 from charms.mongodb.v1.helpers import generate_password
-from ops.charm import (
-    CharmBase,
-    EventBase,
-    RelationBrokenEvent,
-    RelationChangedEvent,
-    RelationEvent,
-)
+from ops.charm import CharmBase, EventBase, RelationBrokenEvent, RelationChangedEvent
 from ops.framework import Object
 from ops.model import Relation
 from pymongo.errors import PyMongoError
@@ -94,11 +88,6 @@ def pass_sanity_hook_checks(self) -> bool:
         if not self.charm.db_initialised:
             return False
 
-        # Warning: the sanity_hook_checks can pass when the call is
-        # issued by a config-sever because the config-server is allowed to manage the users
-        # in MongoDB. This is not well named and does not protect integration of a config-server
-        # to a client application. The mongos charm however doesn't care
-        # because it supports only one integration that uses MongoDBProvider.
         if not self.charm.is_role(Config.Role.MONGOS) and not self.charm.is_relation_feasible(
             self.get_relation_name()
         ):
@@ -110,14 +99,8 @@ def pass_sanity_hook_checks(self) -> bool:
 
         return True
 
-    def pass_hook_checks(self, event: RelationEvent) -> bool:
+    def pass_hook_checks(self, event: EventBase) -> bool:
         """Runs the pre-hooks checks for MongoDBProvider, returns True if all pass."""
-        # First, ensure that the relation is valid, useless to do anything else otherwise
-        if not self.charm.is_role(Config.Role.MONGOS) and not self.charm.is_relation_feasible(
-            event.relation.name
-        ):
-            return False
-
         if not self.pass_sanity_hook_checks():
             return False
 
@@ -218,6 +201,7 @@ def remove_users(
         Raises:
             PyMongoError
         """
+
         with MongoConnection(self.charm.mongo_config) as mongo:
             for username in users_being_managed - expected_current_users:
                 logger.info("Remove relation user: %s", username)
@@ -227,6 +211,15 @@ def remove_users(
                 ):
                     continue
 
+                # for user removal of mongos-k8s router, we let the router remove itself
+                if (
+                    self.charm.is_role(Config.Role.CONFIG_SERVER)
+                    and self.substrate == Config.Substrate.K8S
+                ):
+                    logger.info("K8s routers will remove themselves.")
+                    self._remove_from_relational_users_to_manage(username)
+                    return
+
                 mongo.drop_user(username)
                 self._remove_from_relational_users_to_manage(username)
 
@@ -514,6 +507,25 @@ def _add_to_relational_users_to_manage(self, user_to_add: str) -> None:
         current_users.add(user_to_add)
         self._update_relational_users_to_manage(current_users)
 
+    def remove_all_relational_users(self):
+        """Removes all users from DB.
+
+        Raises: PyMongoError.
+        """
+        with MongoConnection(self.charm.mongo_config) as mongo:
+            database_users = mongo.get_users()
+
+        users_being_managed = database_users.intersection(self._get_relational_users_to_manage())
+        self.remove_users(users_being_managed, expected_current_users=set())
+
+        # now we must remove all of their connection info
+        for relation in self._get_relations():
+            fields = self.database_provides.fetch_my_relation_data([relation.id])[relation.id]
+            self.database_provides.delete_relation_data(relation.id, fields=list(fields))
+
+            # unforatunately the above doesn't work to remove secrets, so we forcibly remove the rest
+            relation.data[self.charm.app].clear()
+
     @staticmethod
     def _get_database_from_relation(relation: Relation) -> Optional[str]:
         """Return database name from relation."""