How to run a service in ubuntu as an unprivileged user?

Question

linux

How to run a service in ubuntu server as an unprivileged user?
Where and what rights need to be corrected?

Answer 1

Use sudo?

Answer 2

in ubuntu it is fashionable to use upstart))
sudo apt-get install daemontools
exec /usr/bin/setuidgid username command
and
args then sudo -u username -b command and args
But not the fact that the service will unfasten in the background