File permissions with Docker

I searched a bit and wasn't able to find anything to help me but I'm currently running my Channels DVR server via Docker on a Raspberry PI that I also run a Plex server on (not in a container). The Plex server is the way I primarily watch my recordings and I've mapped my files so that the DVR recordings show up in Plex. I'm struggling to get the file permissions so that I can delete the recordings in Plex. I can manually do it by chmod everything to 777 but I don't want to have to do this all of the time. I have tried several things including adding root to my plex group as well as even trying to change the userid and groupid that Channels is running under to my Plex user and group (this didn't seem to work as process is still showing running as "root"). I'm sure this is something simple but I'm struggling to get it to work the way I want it to. Any suggestions would be appreciated.