How do I set owner and permissions for files outputted by a container?

[Brian.Unraid]

I'm using a container that monitors a folder for mp3 files and converts them into an m4b file.

 

This project: https://github.com/seanap/auto-m4b

 

I can't figure out how to set the owner or permissions on the m4b file that gets outputted. The files are coming out owned by nobody:nogroup and -rw-r--r--

 

Can anyone explain to me how I can set user, group, and permission for all the files outputted by a container?

 

I've tried setting PUID, PGID, and UMASK in the yaml file. But I'm a total noob with docker-compose and .yml files.

 

On a normal container template I get from the app store, it has PUID:99, PGID:100, UMASK:002, already setup correctly.

 

Any help would be greatly appreciated!

[BendakSK]

In the same boat, looking to see what can be done. Were you able to figure this out?