Install Naemon Core on Ubuntu 16.04

Prepare your system

In this how to, we are going to install all files to /opt/naemon.

If you want to delete Naemon Core, just remove this folder and the systemd config.

All commands needs to run as user root or via sudo.

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

Check for new versions

In this how to I use Naemon 1.0.6. Check if there is a new version available!

cd /tmp/
wget https://github.com/naemon/naemon-core/archive/v1.0.6.tar.gz
tar xfv v1.0.6.tar.gz
cd naemon-core-1.0.6/

./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 - recommended)

Due to I had some issues using the default Naemon systemd service configuration I modified the original a bit.

Copy the following to the file /lib/systemd/system/naemon.service using your favorite editor.

Pitfall!

If you want to use Naemon with the Statusengine Broker Module, it is required that the Gearman Job Server is running, BEFORE your Naemon gets started!
So you need to make sure that systemd will start the Gearman Job Server first.
To configure this, replace the AFTER= line in the following systemd configuration with this:

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

If not already done, install the Gearman Job Server now!

apt-get install gearman-job-server

[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

Now you can check if your Naemon Core is running using systemctl status naemon:

root@xenial:/tmp/naemon-core-1.0.6# systemctl status naemon
● naemon.service - Naemon Monitoring Daemon
   Loaded: loaded (/lib/systemd/system/naemon.service; disabled; vendor preset: enabled)
   Active: active (running) since Mi 2017-05-17 20:04:29 CEST; 11s ago
     Docs: http://naemon.org/documentation
  Process: 15888 ExecStart=/opt/naemon/bin/naemon --daemon /opt/naemon/etc/naemon/naemon.cfg (code=exited, status=0/SUCCESS)
  Process: 15885 ExecStartPre=/opt/naemon/bin/naemon --verify-config /opt/naemon/etc/naemon/naemon.cfg (code=exited, status=0/SUCCESS)
 Main PID: 15890 (naemon)
    Tasks: 6
   Memory: 1.4M
      CPU: 12ms
   CGroup: /system.slice/naemon.service
           ├─15890 /opt/naemon/bin/naemon --daemon /opt/naemon/etc/naemon/naemon.cfg
           ├─15891 /opt/naemon/bin/naemon --worker /opt/naemon/var/naemon.qh
           ├─15892 /opt/naemon/bin/naemon --worker /opt/naemon/var/naemon.qh
           ├─15893 /opt/naemon/bin/naemon --worker /opt/naemon/var/naemon.qh
           ├─15894 /opt/naemon/bin/naemon --worker /opt/naemon/var/naemon.qh
           └─15895 /opt/naemon/bin/naemon --daemon /opt/naemon/etc/naemon/naemon.cfg

Mai 17 20:04:29 xenial systemd[1]: Starting Naemon Monitoring Daemon...
Mai 17 20:04:29 xenial systemd[1]: Started Naemon Monitoring Daemon.
root@xenial:/tmp/naemon-core-1.0.6#

To make sure that you Naemon will start automatically on boot, you need to enable the systemd configuration:

systemctl enable naemon.service

Install Monitoring Plugins

By default, Naemon will install a sample config with some basic checks. So you need to install the monitoring plugins to get them to work.

apt-get install monitoring-plugins

Setup Logrotate

To avoid, that the size of your naemon.log grows up in the sky you should configure the logrotate daemon.

Modify the file /opt/naemon/etc/logrotate.d/naemon until it fulfill your needs.

Than copy it to /etc/logrotate.d/ to enable the configuration

Congrats! You installed Naemon Core!

Load Statusengine Broker Module

Now you are ready to install and load the Statusengine Broker Module.

Start Naemon in foreground (expert or debugging)

For some reasons it can be useful to run Naemon in foreground.

You can do this with this command /opt/naemon/bin/naemon /opt/naemon/etc/naemon/naemon.cfg

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

Naemon Core 1.0.6-source
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 1.0.6-source starting... (PID=1323)
Local time is Wed May 17 20:34:50 CEST 2017
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!
wproc: Successfully registered manager as @wproc with query handler
wproc: Registry request: name=Core Worker 1325;pid=1325
wproc: Registry request: name=Core Worker 1327;pid=1327
wproc: Registry request: name=Core Worker 1326;pid=1326
wproc: Registry request: name=Core Worker 1324;pid=1324
Successfully launched command file worker with pid 1328
^CCaught 'Interrupt', shutting down...
Successfully shutdown... (PID=1323)
Event broker module 'NERD' deinitialized successfully.
Warning: Cannot open log file '(null)' for writing
Successfully reaped command worker (PID = 1328)
naemon@xenial:~$