Changing postgres User

Hi,

We are trying to setup a postgresql Docker container alongside pgadmin and caddy for use in the PrairieLearn student testing software. Our main set back is that the PrairieLearn production environment user runs as user 1001:1001 and as such we have had to rename the postgres user within Linux to 1001 and alter the credentials management significantly. 

We are currently brainstorming some better ways but if anyone has any suggestions on easier ways to make these changes then we would appreciate them. The code is open source and can be viewed here - https://github.com/PrairieLearn/PrairieLearn/pull/10713

Thanks, 

Zac