Be able to run the container as a non root user

[mattdale77]

Is your feature request related to a problem? Please describe.
It is related to security. I would like the resulting docker containers to run as a non root user so the files accessed do not need to be owned by root

Describe the solution you'd like
I would like the generated docker-compose to be able to use a non root user. If this is not possible the fixuid can be implemented at the build stage.

Describe alternatives you've considered
I tried to add the user tag into the docker compose but this would not run as it could not access the files in the container

Additional context