Install Naemon Core on Ubuntu

This guide installs Naemon Core 1.5.2 from source on Ubuntu 26.04 LTS (Resolute Raccoon).

Everything goes to /opt/naemon. To remove Naemon later, delete that directory and the systemd unit. All commands run as root, or via sudo.

Prepare your system

addgroup --system naemon
adduser --system naemon
adduser naemon naemon

Install dependencies

apt-get update
apt-get install build-essential automake gperf help2man libtool libglib2.0-dev

Download and install Naemon Core

ℹ️

This guide pins Naemon 1.5.2. Check whether a newer version is available before you start.

cd /tmp/
wget https://github.com/naemon/naemon-core/archive/v1.5.2.tar.gz
tar xfv v1.5.2.tar.gz
cd naemon-core-1.5.2/

./autogen.sh --prefix=/opt/naemon --with-naemon-user=naemon --with-naemon-group=naemon --with-pluginsdir=/usr/lib/nagios/plugins
make all
make install

mkdir -p /opt/naemon/var/
mkdir -p /opt/naemon/var/cache/naemon
mkdir -p /opt/naemon/var/spool/checkresults
chown naemon:naemon /opt/naemon/var -R

mkdir /opt/naemon/etc/naemon/module-conf.d
chown naemon:naemon /opt/naemon/etc -R

Start Naemon Core through systemd

🚫

Pitfall! If you are going to use Naemon with the Statusengine broker module , the Gearman Job Server has to be running before Naemon starts, so systemd needs to know about the dependency. Replace the After= line below with:

After=network.target gearman-job-server.service

If you have not installed it yet:

apt-get install gearman-job-server

Put the following in /etc/systemd/system/naemon.service. It is the unit shipped with Naemon with a few adjustments.

[Unit]
Description=Naemon Monitoring Daemon
Documentation=http://naemon.org/documentation
After=network.target

[Service]
Type=forking
PIDFile=/opt/naemon/var/cache/naemon/naemon.pid
ExecStartPre=/opt/naemon/bin/naemon --verify-config /opt/naemon/etc/naemon/naemon.cfg
ExecStart=/opt/naemon/bin/naemon --daemon /opt/naemon/etc/naemon/naemon.cfg
ExecReload=/bin/kill -HUP $MAINPID
User=naemon
Group=naemon
StandardOutput=journal
StandardError=inherit

[Install]
WantedBy=multi-user.target

systemctl daemon-reload
systemctl start naemon

Check that it came up with systemctl status naemon:

● naemon.service - Naemon Monitoring Daemon
     Loaded: loaded (/etc/systemd/system/naemon.service; disabled; preset: enabled)
     Active: active (running)
       Docs: http://naemon.org/documentation
    Process: 48031 ExecStartPre=/opt/naemon/bin/naemon --verify-config /opt/naemon/etc/naemon/naemon.cfg (code=exited, status=0/SUCCESS)
    Process: 48032 ExecStart=/opt/naemon/bin/naemon --daemon /opt/naemon/etc/naemon/naemon.cfg (code=exited, status=0/SUCCESS)
   Main PID: 48033 (naemon)
      Tasks: 6
     CGroup: /system.slice/naemon.service
             ├─48033 /opt/naemon/bin/naemon --daemon /opt/naemon/etc/naemon/naemon.cfg
             └─48034 /opt/naemon/bin/naemon --worker /opt/naemon/var/naemon.qh

The line to look for in the pre-flight check is Things look okay - No serious problems were detected.

To start Naemon on boot:

systemctl enable naemon.service

Install monitoring plugins

Naemon installs a sample configuration with some basic checks, so you need the plugins for those checks to work:

apt-get install monitoring-plugins

Set up logrotate

To stop naemon.log growing without bound, adjust /opt/naemon/etc/logrotate.d/naemon to your needs and copy it to /etc/logrotate.d/ to activate it.

Congratulations, you have installed Naemon Core.

ℹ️

You are now ready to install and load the Statusengine broker module .

Running Naemon in the foreground

For debugging it can be useful to run Naemon in the foreground instead. Exit with Ctrl+C.

root@ubuntu:/opt/naemon# sudo -u naemon /bin/bash
naemon@ubuntu:/opt/naemon$ /opt/naemon/bin/naemon /opt/naemon/etc/naemon/naemon.cfg

Naemon Core 1.5.2
Copyright (c) 2013-present Naemon Core Development Team and Community Contributors
Copyright (c) 2009-2013 Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
License: GPL

Website: http://www.naemon.org
Naemon 1.5.2 starting... (PID=52156)
qh: Socket '/opt/naemon/var/naemon.qh' successfully initialized
nerd: Channel hostchecks registered successfully
nerd: Channel servicechecks registered successfully
nerd: Fully initialized and ready to rock!
Successfully launched command file worker with pid 52161
^CCaught 'Interrupt', shutting down...
Retention data successfully saved.
Successfully shutdown... (PID=52156)

Install Nagios Core on Ubuntu