create role r1;
create user foo@'127.0.0.1';
grant r1 to foo@'127.0.0.1';
connect  con1,127.0.0.1,foo,,;
show grants;
Grants for foo@127.0.0.1
GRANT `r1` TO `foo`@`127.0.0.1`
GRANT USAGE ON *.* TO `foo`@`127.0.0.1`
set role r1;
select * from information_schema.enabled_roles;
ROLE_NAME
r1
connection default;
drop user foo@'127.0.0.1';
drop role r1;