[systemd-devel] Need help with getting messages into /var/log/messages

[Mathieu Bridon]

On Wed, 2012-08-01 at 23:57 -0400, Paul Richards wrote:
> 1. My program just runs once on startup and then exits. Do I need to
> put anything in the service file for that?

Use "Type=oneshot" in the "Service" section.

Otherwise, by default the type is 'simple', and as such systemd will
consider your service to be in a failure state when it exits.

> 3. My program can fork on startup if its necessary to. Should I run it
> like that so that it returns immediately? Or just leave it run
> regularly. Since it uses usb communications it takes about half a
> second to quit out of the interrupt loop so maybe I should set the
> fork flag in the service file and have it run that way or is it better
> to just run regularly from systemd?

If you set it to fork on startup, then you must use "Type=forking",
otherwise systemd will consider the service to be stopped when the first
parent exits and will kill all remaining children.

But you said above that your program will exit, so that means it's not
something that runs in the background as a service, like e.g httpd ?

If so, then "Type=oneshot" is better, systemd will fork to run the
command anyway, and your service will be considered finished (but not
failed) when it exits.

(Note: you might be interested in the RemainAfterExit option, depending
on your use case)

> 4. I am making rpms for this program as well, should I have the
> service files go into '/etc/systemd/system' or in
> '/lib/systemd/system'?

They should go in %{_unitdir} ;)
https://fedoraproject.org/wiki/Packaging:Systemd#Filesystem_locations


-- 
Mathieu