Failed to start nagios.service: Unit nagios.service failed to load: No such file or directory

Question

I have been following this tutorial:

$ sudo systemctl start nagios
Failed to start nagios.service: Unit nagios.service failed to load: No such file or directory.

What is the cause of problem?

I have:

$ sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Nagios Core 4.0.8
Copyright (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 08-12-2014
License: GPL

Website: http://www.nagios.org
Reading configuration data...
   Read main config file okay...
   Read object config files okay...

Running pre-flight check on configuration data...

Checking objects...
    Checked 8 services.
    Checked 1 hosts.
    Checked 1 host groups.
    Checked 0 service groups.
    Checked 1 contacts.
    Checked 1 contact groups.
    Checked 24 commands.
    Checked 5 time periods.
    Checked 0 host escalations.
    Checked 0 service escalations.
Checking for circular paths...
    Checked 1 hosts
    Checked 0 service dependencies
    Checked 0 host dependencies
    Checked 5 timeperiods
Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...

Total Warnings: 0
Total Errors:   0

Things look okay - No serious problems were detected during the pre-flight check

Solution

I created this file:

 sudo vi /etc/systemd/system/nagios.service

and added the following:

[Unit]
Description=Nagios
BindTo=network.target


[Install]
WantedBy=multi-user.target

[Service]
User=nagios
Group=nagios
Type=simple
ExecStart=/usr/local/nagios/bin/nagios /usr/local/nagios/etc/nagios.cfg

Then the following:

   sudo systemctl enable /etc/systemd/system/nagios.service
   sudo systemctl  start nagios
   sudo systemctl  restart nagios

Comments

[sof]

you should give yourself credit for answering your own question :D

[sof]

no, but they are allowed to mark them as as the correct answer. You hadn't done that yet. Which was sort of what I was implying: I tried your answer, and it worked for me. Might as well mark it as the "correct" one :D

[Ali Hasan]

You can also operate it with sudo service nagios <action> - (and configtest now I'm upgrading to nagios4 seems to work properly too - with v3 I used to have to do sudo /usr/sbin/nagios3 -v /etc/nagios3/nagios.cfg)