I read a lot about running a docker container with different users (i.e different than root). I was wondering, since its possible to run a docker container with a UID that does not exist on the host, what is the meaning of this? what should I expect? for example, assume the following Dockerfile:
FROM scratch
COPY my-app /app/
WORKDIR /app
USER 110011:110011
CMD ["/app/my-app"]
Assuming my-app doesn't require any special permissions, this works. So I was wondering, what does this mean in term of the host and its user. I know its nameless, but is it really a non existing user? and what does this mean?
I assume that I should expect no permissions on the file system in the container. anything else I should be wary about?
any thoughts would be welcome.
Thanks!