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;