How to prevent a user from being able to see other databases and the tables from other databases?

I want to create a postgres user that can access only one database on the postgres server at all.

Currently my flow is:

create database database1;
create user user1 with password 'pass';
grant all privileges on database database1 to user1;

but user1 can still see a list of dbs, users, tables etc. Is there a way to prevent that user from seeing that info? The user needs to be able to write to and read from that db.

Thanks a lot.