Re: [PATCH] maintenance: use systemd timers on Linux

From: brian m. carlson <sandals@crustytoothpaste.net>
Date: May 1, 2021, 20:02 UTC
Message-ID: <YI2zzKMJ1eDH3U/S@camp.crustytoothpaste.net>
In-Reply-To: <20210501145220.2082670-1-lenaic@lhuard.fr>

On 2021-05-01 at 14:52:20, Lénaïc Huard wrote:

Show 19 quoted lines

> The existing mechanism for scheduling background maintenance is done
> through cron. On Linux systems managed by systemd, systemd provides an
> alternative to schedule recurring tasks: systemd timers.
> 
> The main motivations to implement systemd timers in addition to cron
> are:
> * cron is optional and Linux systems running systemd might not have it
>   installed.
> * The execution of `crontab -l` can tell us if cron is installed but not
>   if the daemon is actually running.
> * With systemd, each service is run in its own cgroup and its logs are
>   tagged by the service inside journald. With cron, all scheduled tasks
>   are running in the cron daemon cgroup and all the logs of the
>   user-scheduled tasks are pretended to belong to the system cron
>   service.
>   Concretely, a user that doesn’t have access to the system logs won’t
>   have access to the log of its own tasks scheduled by cron whereas he
>   will have access to the log of its own tasks scheduled by systemd
>   timer.

I would prefer to see this as a configurable option. I have systemd installed (because it's not really optional to have a functional desktop on Linux) but I want to restrict it to starting and stopping services, not performing the tasks of cron. cron is portable across a wide variety of systems, including Linux variants (and WSL) that don't use systemd, and I prefer to use more standard tooling when possible.

-- 
brian m. carlson (he/him or they/them)
Houston, Texas, US