Nagios is perhaps the most complete solution for network and equipment monitoring on Linux. It has everything you need to do the job properly. However, once it is installed it lacks the plugins that give the application real utility.

With these plugins, you will be able to monitor many events in the server as well as in the rest of the computers in the network.

So let’s go for it.

1) Install Nagios on Debian 10

Obviously, the first step is to install Nagios on Debian 10. In addition, some packages have to be installed for the compilation of other packages.

So you can read our post about Nagios on Debian 10.

How to install Nagios on Debian 10?

Then, after the installation, we can continue.

2) Installing the Nagios plugins on Debian 10

Now we have to download the source code. To do this we will use the wget command.

Navigate to the /tmp/ folder and from there download the file.

:~$ cd /tmp/
:~$ wget -c https://nagios-plugins.org/download/nagios-plugins-2.3.1.tar.gz

--2020-01-31 07:25:23--  https://nagios-plugins.org/download/nagios-plugins-2.3.1.tar.gz
Resolving nagios-plugins.org (nagios-plugins.org)... 72.14.186.43
Connecting to nagios-plugins.org (nagios-plugins.org)|72.14.186.43|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2833267 (2.7M) [application/x-gzip]
Saving to: 'nagios-plugins-2.3.1.tar.gz'

nagios-plugins-2.3.1.tar.gz                100%[=====================================================================================>]   2.70M   714KB/s    in 4.9s    

2020-01-31 07:25:30 (569 KB/s) - 'nagios-plugins-2.3.1.tar.gz' saved [2833267/2833267]

At the time of writing this post, the latest version of the Nagios plugins is 2.3.1. So to get the latest version, first check what it is and replace the version number.

When the download is complete, decompress the downloaded file.

:~$ tar xzf nagios-plugins-2.3.1.tar.gz

Now navigate to the generated folder and prepare to compile the package.

:~$ ./configure --with-nagios-user=nagios --with-nagios-group=nagios
configure: creating ./config.status
config.status: creating gl/Makefile
config.status: creating nagios-plugins.spec
config.status: creating tools/build_perl_modules
config.status: creating Makefile
config.status: creating tap/Makefile
config.status: creating lib/Makefile
config.status: creating plugins/Makefile
config.status: creating lib/tests/Makefile
config.status: creating plugins-root/Makefile
config.status: creating plugins-scripts/Makefile
config.status: creating plugins-scripts/utils.pm
config.status: creating plugins-scripts/utils.sh
config.status: creating perlmods/Makefile
config.status: creating test.pl
config.status: creating pkg/solaris/pkginfo
config.status: creating po/Makefile.in
config.status: creating config.h
config.status: config.h is unchanged
config.status: executing depfiles commands
config.status: executing libtool commands
config.status: executing po-directories commands
config.status: creating po/POTFILES
config.status: creating po/Makefile

Now use the make command to create the package.

:~$ make

Then, perform the installation with the following command:

:~$ sudo make install
ck_ifoperstatus check_mailq check_file_age check_ssl_validity utils.sh utils.pm '/usr/local/nagios/libexec'
make[2]: Nothing to be done for 'install-data-am'.
make[2]: Leaving directory '/tmp/nagios-plugins-2.3.1/plugins-scripts'
make[1]: Leaving directory '/tmp/nagios-plugins-2.3.1/plugins-scripts'
Making install in plugins-root
make[1]: Entering directory '/tmp/nagios-plugins-2.3.1/plugins-root'
make[2]: Entering directory '/tmp/nagios-plugins-2.3.1/plugins-root'
 /usr/bin/install -c -o nagios -g nagios check_dhcp /usr/local/nagios/libexec/check_dhcp
 chown root /usr/local/nagios/libexec/check_dhcp
 chmod ug=rx,u+s /usr/local/nagios/libexec/check_dhcp
 /usr/bin/install -c -o nagios -g nagios check_icmp /usr/local/nagios/libexec/check_icmp
 chown root /usr/local/nagios/libexec/check_icmp
 chmod ug=rx,u+s /usr/local/nagios/libexec/check_icmp
make[2]: Nothing to be done for 'install-data-am'.
make[2]: Leaving directory '/tmp/nagios-plugins-2.3.1/plugins-root'
make[1]: Leaving directory '/tmp/nagios-plugins-2.3.1/plugins-root'
Making install in po
make[1]: Entering directory '/tmp/nagios-plugins-2.3.1/po'
/usr/bin/mkdir -p /usr/local/nagios/share
installing fr.gmo as /usr/local/nagios/share/locale/fr/LC_MESSAGES/nagios-plugins.mo
installing de.gmo as /usr/local/nagios/share/locale/de/LC_MESSAGES/nagios-plugins.mo
if test "nagios-plugins" = "gettext-tools"; then \
  /usr/bin/mkdir -p /usr/local/nagios/share/gettext/po; \
  for file in Makefile.in.in remove-potcdate.sin    Makevars.template; do \
    /usr/bin/install -c -o nagios -g nagios -m 644 ./$file \
		    /usr/local/nagios/share/gettext/po/$file; \
  done; \
  for file in Makevars; do \
    rm -f /usr/local/nagios/share/gettext/po/$file; \
  done; \
else \
  : ; \
fi
make[1]: Leaving directory '/tmp/nagios-plugins-2.3.1/po'
make[1]: Entering directory '/tmp/nagios-plugins-2.3.1'
make[2]: Entering directory '/tmp/nagios-plugins-2.3.1'
make[2]: Nothing to be done for 'install-exec-am'.
make[2]: Nothing to be done for 'install-data-am'.
make[2]: Leaving directory '/tmp/nagios-plugins-2.3.1'
make[1]: Leaving directory '/tmp/nagios-plugins-2.3.1'

At this point, everything should have gone smoothly. The plugins are installed in the /usr/local/nagios/libexec/ folder so use the ls command to check if they were installed.

:~$ ls /usr/local/nagios/libexec/

As you can see in the image, they were installed correctly.

Now restart the Nagios service to load the plugins.

:~$ sudo systemctl restart nagios

Now let’s see the results.

3) Nagios plugins working

After restarting the Nagios service, open your web browser and log in to Nagios with your username and password.

Now in the Hosts section, you will see the localhost information.

Also the information about the services, then, the plugins were loaded correctly.

And that is it.

Conclusion

This tutorial is an add-on for you to have fully functional Nagios on your Linux server. Now you have learned how to install the plugins of this tool.

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The post How to install the Nagios plugins on Debian 10? appeared first on Linux Windows and android Tutorials.

Pre-requisites:

• SELinux (Passive mode):

sudo sed -i 's/SELINUX=.*/SELINUX=permissive/g' /etc/selinux/config
sudo setenforce 0

Step 1: Installing Dependencies

Update your system.

sudo dnf updates

Install required Dependencies.

sudo dnf install @php

sudo dnf install @perl @httpd wget unzip glibc automake glibc-common gettext autoconf php php-cli gcc gd gd-devel net-snmp openssl-devel unzip net-snmp postfix net-snmp-utils

Guide for Installing Development Tools on RHEL 8 / Cento 8.

sudo dnf groupinstall "Development Tools"

Now, start and enable httpd and php-fpm services.

sudo systemctl enable --now httpd php-fpm

Checki status is running.

systemctl status http php-fpm

Detailed instructions for the Installation of PHP and httpd.

Step 2: Downloading Nagios Core

Change directory to /usr/src/. Go to latest-release page of Nagios to download.

sudo su -
cd /usr/src

Create nagios-$VER directory.

Download & extract Nagios tarball.

https://github.com/NagiosEnterprises/nagioscore/releases

Change path to created folder.

cd nagios-$VER

Step 3: Compile Nagios Core on Centos 8 / RHEL 8.

a. Run the configure script by command below:

./configure

Output:

b. To compile the main program and CGIs, run the make command with all options.

sudo make all

Output:

c. Create User And Group

This will create user and groups in Nagios

Add apache user to Nagios Group.

make install-groups-users
usermod -a -G nagios apache

d. Install Nagios on Centos / RHEL 8.

Install Nagios base.

make install

e. Install the init script in /lib/systemd/system.

make install-init

f. Install and configure the permissions on the directory for holding the external command file.

make install-commandmode

g. Install sample config files in /usr/local/nagios/etc.

make install-config

h. Install the Apache config file for the Nagios web interface.

make install-webconf

i. Install the Exfoliation theme for the Nagios web interface.

make install-exfoliation

j. You can install classic theme for Nagios web interface by given command

make install-classicui

Step 4: Creating Nagios Web User

We need to create a user account for Nagios web interface . Use the given command:

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

Restart Apache services to take effect.

systemctl restart httpd

Step 5: Installing Nagios Plugins

Plugins are used to provide more monitoring features.
Switch to /usr/src directory.

cd /usr/src

Create new directory as nagios-plugins-$VER

mkdir nagios-plugins-$VER

Download Nagios plugins from Github releases page.

Extract it to /usr/src/nagios-plugins-$VER directory.

Now, change directory to nagios-$VER.

cd 'nagios-$VER'

Use this command to install and compile Nagios Plugins.

./configure --with-nagios-user=nagios --with--nagios-group=nagios
make && make install

Output:

Step 6: Verifying Installation & Starting Nagios Services.

Make sure your Nagios installation is working properly.

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

Start & Enable Nagios service to start at boot.

sudo systemctl enable --now nagios

Re-check the service status.

systemctl status nagios

Step 7: Accessing Nagios Web Dashboard

Remove firewall restrictions:

sudo firewall-cmd --permanent --add-service={http,https}
sudo firewall-cmd --reload

Access Dashboard by visiting http:[IP/hostname]/nagios/
Fill out Authentication details:

Username: nagiosadmin

You can add device to be monitored in Dashboard.

The post How To Install Nagios 4 on Centos 8 / RHEL 8. appeared first on Linux Windows and android Tutorials.