want to write a systemd service file where a user may not exist.

[Ralf Mardorf]

On Sat, 11 Feb 2017 12:07:13 +0000, Colin Law wrote:
>If you run
>sudo system enable|disable sarra
>then you should see it adding or removing the links.

Typo
systemctl ;)

However, if we install a package with a systemd unit, it automatically
gets enable. You could test it, e.g. install smartmontools. A user who
just want to get "smartctl" needs to manually disable the daemon. The
Ubuntu policy is very bad, it's better to be aware of it, to avoid
serious issues.