the Seafile manual has been updated recently, a version 10.0.3 for CE is coming and a version 10.0.7 for PRO, read the database configuration passage in the manual:
When set `use_ssl` to true and `skip_verify` to false, it will check whether the MySQL server certificate is legal through the CA configured in `ca_path`. The `ca_path` is a trusted CA certificate path for signing MySQL server certificates. When `skip_verify` is true, there is no need to add the `ca_path` option. The MySQL server certificate won't be verified at this time.
Since Seafile 10.0.3 and 10.0.7 Pro, you can use unix_socket authentication plugin provided by MariaDB/MySQL. To enable it, you need to specify the `unix_socket` option without user name and password.
#user = root
#password = root
unix_socket = /var/run/mysqld/mysqld.sock