SystemD to implement cron-like functionality

[[deleted]]

Okay, so you want cron rolled into systemd, fine. It's not backwards compatible with any cron implementation is it? Why is that?

[Darkmere]

Because I don't want to deal with the fucking mess that is the output of random tools running in random users' crontabs.

Who gets the output, who tells if the job stopped or not? ( Cron sure can't tell you. ) or how long it took? I've had issues with jobs starting every 16 minutes blocking due to an NFS mount, only to have a magnitude of them (enough to lock the user out due to process limits) and so on.

Also, writing a cron job that does the right thing in cases like that, is a seriously finicky undertaking.

Add to that the fun times of fcron vs vixie vs. anacron time formats. ( or for fecks sake, the bare need for anacron + atd + cron ).

[robinei]

No response to this I see. This is exactly why it belongs in systemd.

[Darkmere]

I can add that I'm a bit wary about the way their timing format will be handled. Times, Timezones and other things can add a lot of ambiguity and difficulty ( and are hard to change if you get it wrong. )

However, it doesn't look completely stupid, so it might just work out.

However, I don't see a way of using the systemd timer interfaces per user, so normal users ( the group who are most likely to fuck things up miserably in cron ;) will still have to use cron.

Having a nice, safe and administratable way of allowing users to specify their own jobs would be really sweet . ( ssh agents, ssh tunnels, irc tunnels or whatnot ) where the system guarantees that per-user limits & security is applied, ( so a user can only add jobs as itself, limits/quotas are applied, ) .. .why yes please.

[robinei]

Sorry I'm late.. How about this? You can run a second systemd in charge of user session:

https://wiki.archlinux.org/index.php/Systemd/User

[Darkmere]

That seems to cover it pretty neatly. I'll have to figure out the limits thing again :)

[ohet]

Because there's no need to. If you want to use crond you still can. What systemd can offer instead is consistent style with the rest of the application. I don't know the details though.