Notes SystemD

Voir :

• journalctl
• 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
• Durcir nginx et PHP avec systemd

Hardening Security focused systemd configuration

Lister les services

systemctl list-unit-files
systemctl list-units

Lister les services inactifs

systemctl list-units -all --state=inactive

Lister les services KO

systemctl -a |grep dead

Lister les services actifs

# SystemD
systemctl list-units --type service --state active
 
# Avant SystemD
chkconfig --list |grep -E '[1-5]:on'

Savoir si le service est activé ou désactivé

systemctl is-active httpd
systemctl is-enabled httpd

Relire la conf

systemctl daemon-reload

Les différents types de services

• http://doc.fedora-fr.org/wiki/Systemd#Type_de_service

Runlevel et Target

Voir :

• https://www.redhat.com/en/blog/introducing-hirte-deterministic-multi-node-service-controller

Exemple

hirtectl start rpi4 httpd.service

systemctl show --property=Environment docker

If you don't like systemctl's auto-paging feature

export SYSTEMD_PAGER=

journalctl --since "2019-10-16 06:00" --until "2019-10-16 10:00" 

export _SYSTEMCTL_SKIP_REDIRECT=1

[Service]
PrivateTmp=true

—

man -k tmpfiles

/etc/tmpfiles.d

/etc/tmpfiles.d/python.conf

x   /tmp/pymp-*

systemctl reboot

Voir Notes langue lang locale - SystemD

#timedatectl list-timezones
timedatectl set-timezone Europe/Paris

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/