Roles are supported according to (https://blog.mariadb.org/mariadb-10-0-beta-launched-an-important-milestone/)

So the following commands worked:
create role read_only;
grant select on example.* to read_only;
grant usage on example.* to read_only;

grant select on example.* to app_report@'localhost';
When i logged in as app_report, show databases did not show the example database.  And selects against tables in the example database did not work.
What am I missing?

Thanks,
Adam C. Scott