Bug 2372726

Summary: Use `systemctl kill` in logrotate postrotate script
Product: [Fedora] Fedora Reporter: Marcos Mello <marcosfrm>
Component: monitorixAssignee: Jordi Sanfeliu <jordi>
Status: MODIFIED --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: unspecified    
Version: 43CC: jordi
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OS: Linux   
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Description Marcos Mello 2025-06-13 17:24:52 UTC 
`systemctl kill` leverages systemd's knowledge of the daemon's main PID, eliminating the need to rely on PID files or external tools like `killall` or `pkill`. This ensures precise signal sending to the intended process, reducing the risk of errors in process identification. Additionally, using `systemctl kill` logs the signal sending in the service's journal, providing a record of actions taken. Requires selinux-policy-41.43 or higher (see https://bugzilla.redhat.com/show_bug.cgi?id=2369644), available as an update for F41, F42, and Rawhide.

https://bodhi.fedoraproject.org/updates/FEDORA-2025-eb98eb9e24 (F41 -- will go to stable in a few days)
https://bodhi.fedoraproject.org/updates/FEDORA-2025-f9f097f491 (F42 -- stable)
https://bodhi.fedoraproject.org/updates/FEDORA-2025-3db4c0ec1c (Rawhide)

The logrotate configuration snippet:

# cat /etc/logrotate.d/monitorix
/var/log/monitorix /var/log/monitorix-httpd {
        nocompress
        missingok
        postrotate
                /bin/kill -HUP `cat /var/run/monitorix.pid 2>/dev/null` 2> /dev/null || true
        endscript
}

In the postrotate script, kill can be replaced by:

/usr/bin/systemctl kill --signal=HUP --kill-whom=main monitorix.service 2>/dev/null || true

Because:

# systemctl show -P MainPID monitorix.service
2109
# cat /var/run/monitorix.pid
2109

Reproducible: Always




Additional Information:
monitorix-3.16.0-2.fc42.noarch
Comment 1 Jordi Sanfeliu 2025-06-19 10:27:04 UTC 
If I apply your suggested change then log logrotation won't work on RHEL8 and derivatives:

# /usr/bin/systemctl kill --signal=HUP --kill-whom=main monitorix.service
/usr/bin/systemctl: unrecognized option '--kill-whom=main'
Comment 2 Marcos Mello 2025-06-19 16:09:46 UTC 
Before systemd 252, the option was --kill-who (still supported for compatibility in later versions). I didn't consider EPEL builds because it's unclear whether the required SELinux policy update for `systemctl kill` to function in this context will be backported to RHEL (RHEL 9 already includes systemd 252, by the way). Thus, this modification applies only to Fedora.
Comment 3 Jordi Sanfeliu 2025-09-01 14:40:03 UTC 
Forgot to reply here that I've pushed a commit that should fix this:

<https://github.com/mikaku/Monitorix/commit/15f9c86b3866e2c940534303cc2393dd887e1188>
Comment 4 Marcos Mello 2025-09-02 12:47:10 UTC 
The RHEL SELinux policy *needs* to have this commit (present in Fedora 41+)

https://github.com/fedora-selinux/selinux-policy/commit/3daaed0cc20a19afd48e82231d1d0ae45129d66d

otherwise it won't work. Therefore, it's better to use `0%{?fedora} >= 41` for now.
Comment 5 Fedora Release Engineering 2026-05-06 13:14:09 UTC 
This message is a reminder that Fedora Linux 42 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora Linux 42 on 2026-05-13.
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