Nagios 4 – Debian`i serverile

Debian | Raspbian

All steps on Debian require to run as root. To become root simply run:

Debian:

su

 

Raspbian:

sudo -i

 

All commands from this point onwards will be as root.

 

Security-Enhanced Linux

This guide is based on SELinux being disabled or in permissive mode. SELinux is not enabled by default on Debian. If you would like to see if it is installed run the following command:

dpkg -l selinux*

 

Prerequisites

Perform these steps to install the pre-requisite packages.

===== 7.x / 8.x =====

apt-get update
apt-get install -y autoconf gcc libc6 make wget unzip apache2 apache2-utils php5 libgd2-xpm-dev

 

===== 9.x =====

apt-get update
apt-get install -y autoconf gcc libc6 make wget unzip apache2 apache2-utils php libgd-dev

 

Downloading the Source

cd /tmp
wget -O nagioscore.tar.gz https://github.com/NagiosEnterprises/nagioscore/archive/nagios-4.4.1.tar.gz
tar xzf nagioscore.tar.gz

 

Compile

cd /tmp/nagioscore-nagios-4.4.1/
./configure --with-httpd-conf=/etc/apache2/sites-enabled
make all

 

Create User And Group

This creates the nagios user and group. The www-data user is also added to the nagios group.

make install-groups-users
usermod -a -G nagios www-data

 

Install Binaries

This step installs the binary files, CGIs, and HTML files.

make install

 

Install Service / Daemon

This installs the service or daemon files and also configures them to start on boot.

make install-daemoninit

 

Information on starting and stopping services will be explained further on.

 

Install Command Mode

This installs and configures the external command file.

make install-commandmode

 

Install Configuration Files

This installs the *SAMPLE* configuration files. These are required as Nagios needs some configuration files to allow it to start.

make install-config

 

Install Apache Config Files

This installs the Apache web server configuration files and configures the Apache settings.

make install-webconf
a2enmod rewrite
a2enmod cgi

 

Configure Firewall

You need to allow port 80 inbound traffic on the local firewall so you can reach the Nagios Core web interface.

iptables -I INPUT -p tcp --destination-port 80 -j ACCEPT
apt-get install -y iptables-persistent

Answer yes to saving existing rules

 

Create nagiosadmin User Account

You’ll need to create an Apache user account to be able to log into Nagios.

The following command will create a user account called nagiosadmin and you will be prompted to provide a password for the account.

htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

 

 

Start Apache Web Server

===== 7.x =====

Need to restart it because it is already running.

service apache2 restart

 

===== 8.x / 9.x =====

Need to restart it because it is already running.

systemctl restart apache2.service

 

Start Service / Daemon

This command starts Nagios Core.

===== 7.x =====

service nagios start

 

===== 8.x / 9.x =====

systemctl start nagios.service

 

Test Nagios

Nagios is now running, to confirm this you need to log into the Nagios Web Interface.

Point your web browser to the ip address or FQDN of your Nagios Core server, for example:

http://10.25.5.143/nagios

http://core-013.domain.local/nagios

You will be prompted for a username and password. The username is nagiosadmin (you created it in a previous step) and the password is what you provided earlier.

Once you have logged in you are presented with the Nagios interface. Congratulations you have installed Nagios Core.

BUT WAIT …

Currently you have only installed the Nagios Core engine. You’ll notice some errors under the hosts and services along the lines of:

(No output on stdout) stderr: execvp(/usr/local/nagios/libexec/check_load, ...) failed. errno is 2: No such file or directory

These errors will be resolved once you install the Nagios Plugins, which is covered in the next step.

 

Installing The Nagios Plugins

Nagios Core needs plugins to operate properly. The following steps will walk you through installing Nagios Plugins.

Please note that the following steps install most of the plugins that come in the Nagios Plugins package. However there are some plugins that require other libraries which are not included in those instructions. Please refer to the following KB article for detailed installation instructions:

Documentation – Installing Nagios Plugins From Source

 

Prerequisites

Make sure that you have the following packages installed.

apt-get install -y autoconf gcc libc6 libmcrypt-dev make libssl-dev wget bc gawk dc build-essential snmp libnet-snmp-perl gettext

 

Downloading The Source

cd /tmp
wget --no-check-certificate -O nagios-plugins.tar.gz https://github.com/nagios-plugins/nagios-plugins/archive/release-2.2.1.tar.gz
tar zxf nagios-plugins.tar.gz

 

Compile + Install

cd /tmp/nagios-plugins-release-2.2.1/
./tools/setup
./configure
make
make install

 

Test Plugins

Point your web browser to the ip address or FQDN of your Nagios Core server, for example:

http://10.25.5.143/nagios

http://core-013.domain.local/nagios

Go to a host or service object and “Re-schedule the next check” under the Commands menu. The error you previously saw should now disappear and the correct output will be shown on the screen.

 

Service / Daemon Commands

Different Linux distributions have different methods of starting / stopping / restarting / status Nagios.

===== 7.x =====

service nagios start
service nagios stop
service nagios restart
service nagios status

 

===== 8.x / 9.x =====

systemctl start nagios.service
systemctl stop nagios.service
systemctl restart nagios.service
systemctl status nagios.service