Rundeck supports a number of user directory configurations. By default, the installation uses a file based directory, but connectivity to LDAP is also available. See Authentication.
The Rundeck installation process will have defined a set of temporary logins useful during the getting started phase.
user: Has access to run commands and jobs but unable to modify job definitions. Password: "user"
admin: Belongs to the "admin" group and is automatically granted the "admin" and "user" role privileges. Password: "admin"
If you installed Rundeck using the RPM installation method, it will have created a unix group called "rundeck".
$ groups rundeck rundeck : rundeck
Consult the usermod command to modify a user account.