{{tag>Brouillon SystemD}}

= Notes SystemD

Voir :
* [[Systemd journalctl journal logs|journalctl]]
* [[redhat_acces_var_log_mariadb_mariadb.log_sans_etre_root|systemd service dépendant d'un autre service]]
* https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units
* https://www.digitalocean.com/community/tutorials/understanding-systemd-units-and-unit-files
* https://linuxembedded.fr/2021/11/limiter-les-ressources-dune-ligne-de-commande-avec-systemd
* [[https://linuxfr.org/users/samuel/journaux/durcir-nginx-et-php-avec-systemd|Durcir nginx et PHP avec systemd]]

[[https://github.com/konstruktoid/hardening/blob/master/systemd.adoc|Hardening Security focused systemd configuration]]

Lister les services
<code bash>
systemctl list-unit-files
systemctl list-units
</code>

Lister les services inactifs 
<code bash>
systemctl list-units -all --state=inactive
</code>

Lister les services KO
<code bash>
systemctl -a |grep dead
</code>

Lister les services actifs
<code bash>
# SystemD
systemctl list-units --type service --state active

# Avant SystemD
chkconfig --list |grep -E '[1-5]:on'
</code>

Savoir si le service est activé ou désactivé
<code bash>
systemctl is-active httpd
systemctl is-enabled httpd
</code>

Relire la conf
<code bash>
systemctl daemon-reload
</code>

Les différents types de services
* http://doc.fedora-fr.org/wiki/Systemd#Type_de_service


Runlevel et Target

| **Runlevel** | **Target**        |
| 0	       | poweroff.target   |
| 1	       | rescue.target     |
| 2, 3, 4      | multi-user.target |
| 5	       | graphical.target  |
| 6            | reboot.target     |


== Contrôler des services (Units) SystemD distants avec Hirte

Voir : 
* [[https://www.redhat.com/en/blog/introducing-hirte-deterministic-multi-node-service-controller]]

Exemple
<code bash>
hirtectl start rpi4 httpd.service
</code>


== Debug

<code bash>
systemctl show --property=Environment docker
</code>


== Autres

If you don't like systemctl's auto-paging feature
<code bash>
export SYSTEMD_PAGER=
</code>


=== Logs entre deux date

<code bash>
journalctl --since "2019-10-16 06:00" --until "2019-10-16 10:00" 
</code>


=== Disable systemd redirection

<code bash>
export _SYSTEMCTL_SKIP_REDIRECT=1
</code>


=== tmpfile

<code ini>
[Service]
PrivateTmp=true
</code>

---

<code bash>
man -k tmpfiles
</code>

/etc/tmpfiles.d

<code - /etc/tmpfiles.d/python.conf>
x   /tmp/pymp-*
</code>

=== reboot

<code bash>
systemctl reboot
</code>


=== Lang Locale

Voir [[notes_langue_lang_locale_temps_timezone_tz|Notes langue lang locale - SystemD]]

<code bash>
#timedatectl list-timezones
timedatectl set-timezone Europe/Paris
</code>


== Pb

=== RemoveIPC - Quand Poettering fait des siennes

Problème si compte UID > 1000 à cause de **RemoveIPC**

https://linuxfr.org/users/neologix/journaux/systemd-attention-a-removeipc

RemoveIPC Directive \\
A new option called RemoveIPC was introduced in RHEL 7.2 through Systemd v219. When set to yes, this option forces a cleanup of all allocated inter-process communication (IPC) resources linked to a user leaving his last session. If a daemon is running as a user with a uid number >=1000, it may crash.

This option should always be set to no by default but, due to the logic of package upgrade, it is highly advisable to set RemoveIPC=no in the /etc/systemd/logind.conf file followed by # systemctl restart systemd-logind (source).

Source : https://www.certdepot.net/rhel7-changes-between-versions/