2023
https://dbdemon.com/rootless_podman_with_some_common_sql_database_systems/
    cat /proc/sys/user/max_user_namespaces
    sudo usermod --add-subuids 200000-201000 --add-subgids 200000-201000 $YOUR_USER
    ??? sudo sysctl user.max_user_namespaces=15000