apt update and apt upgrade every day
This is a guide to automatically run apt update and apt upgrade.
Cronjob: apt update and apt upgrade
You need to modify three files:
/lib/systemd/system/apt-daily.timer/lib/systemd/system/apt-daily-upgrade.timer/etc/cron.daily/apt-compat
After the files are modified as described below you need to restart the systemd daemon with systemctl daemon-reload. When this is done your system will automatically update and upgrade the packages.
apt-daily.timer
This timer is responsible for apt update. The update will update the package lists.
The file should look like this:
[Timer]
OnCalendar=*-*-* 2:18:00
# RandomizedDelaySec=12h
Persistent=trueThe OnCalendar is the time when the timer is executed. You could specify the time with the following format: YYYY-MM-DD HH:MM:SS.
The RandomizedDelaySec is the time when the timer is executed with a random delay. Through randomness you could prevent an big overload at a specific time on the mirrors. This line should be commented out, because we want to ensure that the update is executed before the upgrade. For protecting the mirrors you should use a time which is not exactly at the full, half or quarter hour.
The Persistent flag is important, because it makes sure that the timer is executed even if the system was down at the time when the timer was supposed to be executed.
apt-daily-upgrade.timer
This timer is responsible for apt upgrade. The upgrade will upgrade the packages based on the package lists.
The file should look like this:
[Timer]
OnCalendar=*-*-* 03:18:00
# RandomizedDelaySec=60m
Persistent=trueThe explanation for the lines are the same as for the apt-daily.timer.
It is important that the OnCalendar is after the OnCalendar of the apt-daily.timer. Otherwise the upgrade will be executed before the update.
apt-compat
In this file you need to comment out the line which only contains random_sleep, but not the line which defines the random_sleep function.