How to create read only user in PostgreSQL

read-access.sql

-- Revoke default permissions
REVOKE ALL ON SCHEMA public FROM public
GRANT ALL ON SCHEMA public TO writeuser

-- Create a group
CREATE ROLE readaccess;

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

-- Grant access to future tables
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readaccess;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT USAGE, SELECT ON SEQUENCES TO readaccess;

-- Create a final user with password
CREATE USER tomek WITH PASSWORD 'secret';
GRANT readaccess TO readuser;