Migrate from cron to systemd timers

[Bryan Quigley]

Just a quick draft write up (untested). Happy to test/propose a patch if +1 to change.

REPLACE:
update-notifier-common.cron.daily

WITH:
Timer File
/usr/lib/systemd/system/update-notifier-resume-incomplete.timer
[Unit]
Description=Try to rerun any package data downloads that failed at package install time.

[Timer]
OnCalendar=daily
AccuracySec=24h
Persistent=true

[Install]
WantedBy=timers.target

Service File
/usr/lib/systemd/system/update-notifier-resume-incomplete.service
[Unit]
Description=Try to rerun any package data downloads that failed at package install time.

[Service]
ExecStart=/usr/lib/update-notifier/package-data-downloader

Can Nice or otherwise restrict it via systemd.

REPLACE:
update-notifier-common.cron.weekly

WITH:
Timer File
/usr/lib/systemd/system/update-notifier-new-version.timer
[Unit]
Description=Check to see whether there is a new version of Ubuntu available

[Timer]
OnCalendar=weekly
AccuracySec=24h
Persistent=true

[Install]
WantedBy=timers.target

Service File
/usr/lib/systemd/system/update-notifier-new-version.service
[Unit]
Description=Check to see whether there is a new version of Ubuntu available

[Service]
ExecStart=/usr/lib/ubuntu-release-upgrader/release-upgrade-motd

Can Nice or otherwise restrict it via systemd.

[Steve Langasek (vorlon)]

What is the motivation for such a change? Is it strictly because you want to be able to nice these jobs?

We aren't at a point where generally speaking we are migrating cronjobs to timer units.

[Bryan Quigley (bryanquigley)]

Nope (although that is nice - I personally care more about the other restrictions you can do). I posted to devel-discuss about moving from anacron/cron to timers
https://lists.ubuntu.com/archives/ubuntu-devel-discuss/2019-February/018242.html

My count (in a disco LXD containder) we have 7 timers by default and 9 real cronjobs. (Anacron is also done via systemd timer now, so let's skip a step..)