CheckMK Plugins

Collection of CheckMK monitoring plugins for Linux servers. Tested only on Debian.

Plugins

Plugin	Type	Description
fail2ban.sh	local check	Monitor fail2ban — CRITICAL if stopped, reports total banned IPs and per-jail list
imap.sh	local check	Check IMAP service availability via telnet
debian.sh	local check	Check Debian version age and last dist-upgrade date
samba.sh	local check	Count connected Samba clients and open files
backup.sh	local check	Check backup freshness via logrotate status files on NAS
qemu.sh	local check	Monitor QEMU/KVM virtual machines (state, memory, CPU)
virsh-backup.sh	local check	Check VM backup status and list backup data files
nut.sh	agent plugin	Dump UPS status via NUT (section <<<nut>>>)
mk_mysql	agent plugin	MySQL/MariaDB monitoring — ping, global status/variables (sections <<<mysql_ping>>>, <<<mysql>>>). Based on original Checkmk plugin with capacity and replica sections removed

Installation

Local checks

sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/fail2ban.sh -O /usr/lib/check_mk_agent/local/fail2ban.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/fail2ban.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/imap.sh -O /usr/lib/check_mk_agent/local/imap.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/imap.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/debian.sh -O /usr/lib/check_mk_agent/local/debian.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/debian.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/samba.sh -O /usr/lib/check_mk_agent/local/samba.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/samba.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/backup.sh -O /usr/lib/check_mk_agent/local/backup.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/backup.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/qemu.sh -O /usr/lib/check_mk_agent/local/qemu.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/qemu.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/virsh-backup.sh -O /usr/lib/check_mk_agent/local/virsh-backup.sh && sudo chmod 755 /usr/lib/check_mk_agent/local/virsh-backup.sh

Agent plugins

sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/nut.sh -O /usr/lib/check_mk_agent/plugins/nut.sh && sudo chmod 755 /usr/lib/check_mk_agent/plugins/nut.sh
sudo wget https://raw.githubusercontent.com/rollopack/checkmk-plugin/main/mk_mysql -O /usr/lib/check_mk_agent/plugins/mk_mysql && sudo chmod 755 /usr/lib/check_mk_agent/plugins/mk_mysql

Additional setup

fail2ban — sudoers

The fail2ban.sh check requires passwordless sudo for the checkmk user. Create /etc/sudoers.d/checkmk with:

checkmk ALL=(root) NOPASSWD: /usr/bin/fail2ban-client

Service discovery

After installing the plugins, run service discovery on the CheckMK server:

cmk -I --all
cmk -R

License

GNU General Public License v3.0

Copyright (C) 2026 Rolland Gabriel (https://github.com/rollopack)