set setts.usr to :username;
set setts.dev to :dev;
set setts.db to :db;

create database :db;
create user :username;

grant all privileges on database setts.db to setts.usr;

DO $$
declare
username text := current_setting('setts.usr');
dev      integer := current_setting('setts.dev');
begin
if dev > 0 then
    create database test_keystore;
    grant all privileges on database test_keystore to username;
end if;
END $$