The default 'cassandra' superuser was removed from ScyllaDB, which
broke PGO training. exec_cql.py relied on username/password auth
('cassandra'/'cassandra') to execute setup CQL scripts like auth.cql
and counters.cql.
Switch exec_cql.py to connect via the Unix domain maintenance socket
instead. The maintenance socket bypasses authentication, no credentials
are needed. Additionally, create the 'cassandra' superuser via the
maintenance socket during the populate phase, so that cassandra-stress
keeps working. cassandra-stress hardcodes user=cassandra password=cassandra.
Changes:
- exec_cql.py: replace host/port/username/password arguments with a
single --socket argument; add connect_maintenance_socket() with
wait ready logic
- pgo.py: add maintenance_socket_path() helper; update
populate_auth_conns() and populate_counters() to pass the socket
path to exec_cql.py
Fixes SCYLLADB-1070
Closesscylladb/scylladb#29081
It uses some derived roles and permissions
to exercise auth code paths and also creates new
connection with each stress request to exercise
also transport/server.cc connection handling code.
