Postgresql - roles without linux accounts? Basic question:

what I'm reading describes how to create linux users in parallel with postgresql roles.

However, I don't see the value in creating any of these users in linux - I just want to create a postgresql role - and login to that from my application - or when running psql from the terminal using my own login - but in the role of the project.

e.g. - if the project is 'foo' - I want to have the psql -U foo, but no 'foo' user under linux.  After all - what's the point?  It's a role purely for psql - not for linux.

Is this possible in Postgresql - and if so - how do I do this?

I've trivially created a postgresql user role - without a linux account - but then I cannot ever -U role, as I get an error around peer authentication.

So - I assume I need to change how postgresql is handling permissions - and that's where I'm too green with postgresql to know what I'm doing there.

Perhaps a pointer to a clear little document discussing authentication modes or connection modes and setup for postgresql would help me resolve my issues?
You need to update your pg_hba.conf to allow for a non-peer authentication method.

It’s perfectly normal to create roles which don’t have OS accounts.