notes

systemd

https://opensource.com/article/20/7/systemd-timers

Service unit:
For each .timer file, a matching .service file exists (e.g. foo.timer and foo.service). The .timer file activates and controls the .service file. The .service does not require an [Install] section as it is the timer units that are enabled. If necessary, it is possible to control a differently-named unit using the Unit= option in the timer's [Timer] section.

# pound for comments

create service unit file: /etc/systemd/system/rsync_run.service

[Unit]
Description=Run rsync to update backups
Wants=rsync_run.timer

[Service]
Type=oneshot
ExecStart=/home/pete/bin/rsync_run

[Install]
WantedBy=multi-user.target

view the staus of the service: sudo systemctl status rsync_run.service
journalctl -f option: sudo journalctl -S today -f -u rsync_run.service (tail)
start / run the service: sudo systemctl start rsync_run.service
view the logs of the service: sudo journalctl -S today -u rsync_run.service

create timer: /etc/systemd/system/rsync_run.timer

[Unit]
Description=Run rsync_run.service to update backups
Requires=rsync_run.service

[Timer]
Unit=rsync_run.service
OnCalendar=*-*-* *:*:00

[Install]
WantedBy=timers.target

start but don't enable the service: systemctl start rsync_run.service (in the case of a script, it will only run once)

*:0/1 Every minute
*-*-* 00:15:30	Every day of every month of every year at 15 minutes and 30 seconds after midnight
Weekly	        Every Monday at 00:00:00

systemctl daemon-reload

systemctl list-units

systemctl status *timer

systemctl daemon-reload *** has to be run after any changes

systemctl enable --now rsync_run.timer

systemd-analyze calendar 'Fri *-*-* 00:00:00'

systemctl edit file --full *** no need to reload file, only works on existing files

****

systemctl list-units --type=service

systemctl disable [service_name]

systemctl enable [service_name]

systemctl start [service_name]

systemctl stop [service_name]