How to create a read only user in AWS RDS PostgreSQL and a user with superuser privileges on AWS RDS PostgreSQL

rw_ro_access.sql

--
-- Read only 
--

-- Create a group
CREATE ROLE postgres_ro_group;

-- Grant access to existing tables
GRANT USAGE ON SCHEMA public TO postgres_ro_group;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO postgres_ro_group;

-- Grant access to future tables
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO postgres_ro_group;

-- Create a final user with password
CREATE USER postgres_ro WITH PASSWORD 'secret';
GRANT postgres_ro_group TO postgres_ro;

--
-- Superuser 
--

-- Create a final user with password
CREATE USER postgres_adm WITH PASSWORD 'secret';
GRANT rds_superuser to postgres_adm;