How to Install Nagios on Ubuntu 14.04 Trusty LTS Linux

January 16, 2015 | By the+gnu+linux+evangelist.

Install Nagios Ubuntu 14.04 Trusty

How to Install Nagios Core on Ubuntu 14.04 Trusty LTS GNU/Linux desktop – Step by step Tutorial.

First, Latest Nagios for Ubuntu is a Powerful Monitoring System that enables Organizations to Identify and Resolve IT Infrastructure Problems before they affect Critical Business Processes.

Moreover, the Nagios Workflow Management Features are:

Monitoring: IT staff configure Nagios to monitor critical IT infrastructure components
Alerting: Nagios sends alerts when critical infrastructure components fail and recover
Response: IT staff can acknowledge alerts and begin resolving outages and investigating security alerts immediately
Reporting: Reports provide a historical record of outages, events, notifications, and alert response for later review
Maintenance: Scheduled downtime prevents alerts during scheduled maintenance and upgrade windows
Planning: Trending and capacity planning graphs and reports allow you to identify necessary infrastructure upgrades before failures occur.

How to Install Nagios Core on Ubuntu 14.04 - Featured

First, Open a Shell Terminal emulator window
(Press “Enter” to Execute Commands)

In case first see: Terminal QuickStart Guide.
Then Install the Required Packages
Logins as SuperUser to make shorter the others commmands:
```
sudo su
```
If Got “User is Not in Sudoers file” then see: How to Enable sudo
So to Install the Packages:
```
/napt install php7.0-gd libgd2-xpm-dev build-essential /napache2 libapache2-mod-php7.0
```
After to Add nagios User and Groups
Create the nagios User:
```
useradd nagios
```
Make the nagios Group:
```
groupadd nagios
```
Add the nagios user to the group:
```
/usr/sbin/usermod -G nagios nagios
```
Create a new nagcmd group for allowing external commands to be submitted through the web interface:
```
groupadd nagcmd
```
Add both the nagios & apache users to the Group:
```
usermod -a -G nagcmd nagios
```
```
usermod -a -G nagcmd www-data
```
Last Achieve the SuperUser Session:
```
exit
```
Download Latest Nagios Core Linux Source

Nagios Core tar.gz Archive

Nagios Core
Then Double-Click and Extract Nagios Core into /tmp.

Or from Command Line:
```
tar zxvf ~/Downloads/nagios*.tar.gz -C /tmp/
```

Moreover, to Compile and Install Nagios Core for Ubuntu.

cd /tmp/nagios*

./configure --with-command-group=nagcmd

make all

sudo su

If Got “User is Not in Sudoers file” then see: How to Enable sudo

make install

make install-init

make install-config

make install-commandmode

Follow Installing Nagios Core Web Interface
First, Make the needed directory:
```
mkdir -p /etc/httpd/conf.d/nagios.conf
```
And then Install it:
```
make install-webconf
```

After make the Post-Installation Configuration.

cp -R contrib/eventhandlers/ /usr/local/nagios/libexec/

chown -R nagios:nagcmd /usr/local/nagios/libexec/eventhandlers

Again to Check Nagios Installation.

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

And to Enable the Web Interface on Apache.

/usr/bin/install -c -m 644 sample-config/httpd.conf /etc/apache2/sites-enabled/nagios.conf

a2enmod cgi

service apache2 restart

Finally, to Start up Nagios.
```
/etc/init.d/nagios start
```
Again to Create a nagiosadmin Web User with Pass.
```
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
```
Take Note of the Password!
```
exit
```
And to Access the Nagios Web Interface.
```
http://localhost/nagios
```
User: ‘nagiosadmin’
Pass: That you Setup Before
Download and Install Nagios Plugins

Nagios Plugins Installation

Nagios Plugins Setup