Create user with read only permission in PostgreSQL

Steps:

1. create role:
   
   CREATE ROLE readaccess;
   

2. grant access to existing tables:
   

GRANT USAGE ON SCHEMA public TO readaccess;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readaccess;

1. grant access to future tables:
   
   ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readaccess;
   

2. Create user with password:
   
   CREATE USER grafana WITH PASSWORD 'secretpass@dev';
   

3. grant access to user: GRANT readaccess TO grafana;