fix: assign proper database name to superset user

When running `do cairn-createuser`, the created db did not have the
right name. If the user had been created earlier with SSO, then the
Clickhouse DB did not exist.

changelog.d/20230819_081659_regis.md

@@ -0,0 +1 @@
+- [Bugfix] Fix superset database name in user creation with `do cairn-createuser`. (by @regisb)

tutorcairn/templates/cairn/build/cairn-superset/cairn/ctl.py

@@ -77,7 +77,7 @@ def main():
         "--database",
         help=(
             "Name of the Superset database to which the objects should be linked."
-            " By default, this will be the same as the username."
+            " By default, this will be the 'openedx-<username>'."
         ),
     )
     parser_dashboards.add_argument("username")
@@ -92,7 +92,7 @@ def main():
 # but the "create-user" command fails if the user already exists.
 def bootstrap_user(args):
     # Bootstrap database
-    database_name = args.db or args.username
+    database_name = args.db or f"openedx-{args.username}"
     cairn_bootstrap.create_superset_db(args.username, database_name)
 
     # Get or create user