====== SystemD ======

Une belle doc en français => https://lea-linux.org/documentations/systemd


===== Lire les log =====

--- source: https://www.linuxtricks.fr/wiki/utiliser-journalctl-les-logs-de-systemd

  journalctl
comme tail -f
  journalctl -f

Filtrer par service
  journalctl -u crond


===== Timer =====
Lister les timers
  systemctl list-timers --all

Exemple d'un timer

certbot.timer will execute the certbot.service at 12 am and 12 pm.

<code bash>
# cat /lib/systemd/system/certbot.timer
[Unit]
Description=Run certbot twice daily

[Timer]
OnCalendar=*-*-* 00,12:00:00
RandomizedDelaySec=3600
Persistent=true

[Install]
WantedBy=timers.target
</code>

Script venant de l'install par centos
<code bash>
[Unit]
Description=This is the timer to set the schedule for automated renewals

[Timer]
OnCalendar=daily
RandomizedDelaySec=6hours
Persistent=true

[Install]
WantedBy=timers.target

</code>




and certbot.service will execute the renew command.


<code bash>
# cat /lib/systemd/system/certbot.service
[Unit]
Description=Certbot
Documentation=file:///usr/share/doc/python-certbot-doc/html/index.html
Documentation=https://letsencrypt.readthedocs.io/en/latest/
[Service]
Type=oneshot
ExecStart=/usr/bin/certbot -q renew
PrivateTmp=true
</code>

Script venant de l'install par centos
<code bash>
[Unit]
Description=This service automatically renews any certbot certificates found

[Service]
EnvironmentFile=/etc/sysconfig/certbot
Type=oneshot
ExecStart=/usr/bin/certbot renew $PRE_HOOK $POST_HOOK $RENEW_HOOK $CERTBOT_ARGS
</code>


Surtout de pas oublier d'activer ce timer
  systemctl enable certbot-renew.timer
  systemctl start certbot-renew.timer
  systemctl status certbot-renew.timer