Install Nagios Monitoring in RHEL 7.9

1. Install Nagios Monitoring in RHEL 7.9

Nagios is an awesome Open Source monitoring tool, that provides a more comprehensive monitoring environment to always keep an eye on your all machines/networks whether you are in your data center or just your small labs.

With Nagios, you can monitor your remote hosts and their services remotely on a single window. It shows warnings and indicates if something goes wrong in your servers which eventually helps us to detect some problems before they occur. It helps us to reduce downtime and business losses.

Installing Nagios Core and Nagios Plugin in Linux

  • Step 1: Install Apache and PHP Packages
  • Step 2: Create Nagios User and Group
  • Step 3: Download Nagios Core and Nagios Plugin
  • Step 4: Extract Nagios Core and Nagios Plugins
  • Step 5: Installing and Configuring Nagios Core
  • Step 6: Customizing Nagios Configuration
  • Step 7: Install and Configure the Web Interface for Nagios
  • Step 8: Compile and Install Nagios Plugin
  • Step 9: Verify Nagios Configuration Files
  • Step 10: Add Nagios Services to System Startup
  • Step 11: Allow Nagios Web in Firewall
  • Step 12: Log in to the Nagios Web Interface

Step 1: Install Apache and PHP Packages

We need to install Apache, PHP, and some libraries like gcc, glibc, glibc-common, and GD libraries and their development libraries before installing Nagios with the source.

# yum install -y httpd httpd-tools php gcc glibc glibc-common gd gd-devel make net-snmp

Step 2: Create Nagios User and Group

Create a new nagios user and nagcmd group account and set a password.

[root@tecmint]# useradd nagios
[root@tecmint]# groupadd nagcmd

Next, add both the nagios user and the apache user to the nagcmd group.

[root@tecmint]# usermod -G nagcmd nagios
[root@tecmint]# usermod -G nagcmd apache

Step 3: Download Nagios Core and Nagios Plugin

Create a directory for your Nagios installation and all its future downloads.

[root@tecmint]# mkdir /root/nagios
[root@tecmint]# cd /root/nagios

Step 4: Extract Nagios Core and Nagios Plugins

# tar -xf nagios-4.4.9.tar.gz
# tar -xf nagios-plugins-2.3.3.tar.gz
# ls -l

total 13804
drwxrwxr-x 21 root root     4096 Nov 17 02:22 nagios-4.4.9
-rw-r--r--  1 root root 11339450 Nov 17 03:08 nagios-4.4.9.tar.gz
drwxr-xr-x 15 root root     4096 Mar 11  2020 nagios-plugins-2.3.3
-rw-r--r--  1 root root  2782610 Mar 11  2020 nagios-plugins-2.3.3.tar.gz

Step 5: Installing and Configuring Nagios Core

Now, first, we will configure Nagios Core and to do so we need to go to the Nagios directory and run configure file if everything goes fine, it will show the output in the end as sample output.

# cd nagios-4.4.9/
# ./configure --with-command-group=nagcmd
Creating sample config files in sample-config/ ...


*** Configuration summary for nagios 4.4.9 2022-11-16 ***:

 General Options:
 -------------------------
        Nagios executable:  nagios
        Nagios user/group:  nagios,nagios
       Command user/group:  nagios,nagcmd
             Event Broker:  yes
        Install ${prefix}:  /usr/local/nagios
    Install ${includedir}:  /usr/local/nagios/include/nagios
                Lock file:  /run/nagios.lock
   Check the result directory:  /usr/local/nagios/var/spool/checkresults
           Init directory:  /lib/systemd/system
  Apache conf.d directory:  /etc/httpd/conf.d
             Mail program:  /usr/bin/mail
                  Host OS:  linux-gnu
          IOBroker Method:  epoll

 Web Interface Options:
 ------------------------
                 HTML URL:  http://localhost/nagios/
                  CGI URL:  http://localhost/nagios/cgi-bin/
 Traceroute (used by WAP):  


Review the options above for accuracy.  If they look okay,
type 'make all' to compile the main program and CGIs.

After configuring, we need to compile and install all the binaries with the make all and make install commands, it will install all the needed libraries in your machine and we can proceed further.

# make all
# make install

Nagios Compilation Summary

*** Main program, CGIs and HTML files installed ***

You can continue with installing Nagios as follows (type 'make'
without any arguments for a list of all possible options):

  make install-init
     - This installs the init script in /lib/systemd/system

  make install-commandmode
     - This installs and configures permissions on the
       directory for holding the external command file

  make install-config
     - This installs sample config files in /usr/local/nagios/etc

make[1]: Leaving directory '/root/nagios/nagios-4.4.9'

The following command will install the init scripts for Nagios.

# make install-init

To make Nagios work from the command line we need to install command-mode.

# make install-commandmode

Next, install sample Nagios files, please run the following command.

# make install-config

Nagios Configuration Files Installed

/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc/objects
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/nagios.cfg /usr/local/nagios/etc/nagios.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/cgi.cfg /usr/local/nagios/etc/cgi.cfg
/usr/bin/install -c -b -m 660 -o nagios -g nagios sample-config/resource.cfg /usr/local/nagios/etc/resource.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/templates.cfg /usr/local/nagios/etc/objects/templates.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/commands.cfg /usr/local/nagios/etc/objects/commands.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/contacts.cfg /usr/local/nagios/etc/objects/contacts.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/timeperiods.cfg /usr/local/nagios/etc/objects/timeperiods.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/localhost.cfg /usr/local/nagios/etc/objects/localhost.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/windows.cfg /usr/local/nagios/etc/objects/windows.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/printer.cfg /usr/local/nagios/etc/objects/printer.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/switch.cfg /usr/local/nagios/etc/objects/switch.cfg

*** Config files installed ***

Remember, these are *SAMPLE* config files.  You'll need to read
the documentation for more information on how to actually define
services, hosts, etc. to fit your particular needs.

Step 6: Customizing Nagios Configuration

Open the “contacts.cfg” file with your choice of editor and set the email address associated with the nagiosadmin contact definition to receiving email alerts.

# vi /usr/local/nagios/etc/objects/contacts.cfg

Nagios Email Alerts

###############################################################################
#
# CONTACTS
#
###############################################################################

# Just one contact defined by default - the Nagios admin (that's you)
# This contact definition inherits a lot of default values from the
# 'generic-contact' template which is defined elsewhere.

define contact {

    contact_name            nagiosadmin             ; Short name of user
    use                     generic-contact         ; Inherit default values from generic-contact template (defined above)
    alias                   Nagios Admin            ; Full name of user
    email                   admin@tecmint.com ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******
}

Step 7: Install and Configure the Web Interface for Nagios

We are done with all configurations in the backend, now we will configure the Web Interface For Nagios with the following command. The below command will Configure the Web interface for Nagios and a web admin user will be created “nagiosadmin”.

# make install-webconf

In this step, we will be creating a password for “nagiosadmin”. After executing this command, please provide a password twice and keep it remember because this password will be used when you login into the Nagios Web interface.

# htpasswd -s -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
New password:
Re-type new password:
Adding password for user nagiosadmin

Restart Apache to make the new settings take effect.

# systemctl restart httpd

Step 8: Compile and Install Nagios Plugin

go there and configure and install it as directed below.

# cd /root/nagios
# cd nagios-plugins-2.3.3
# ./configure --with-nagios-user=nagios --with-nagios-group=nagios
# make
# make install

Step 9: Verify Nagios Configuration Files

Now we are all done with the Nagios configuration and it’s time to verify it to do so please insert the following command. If everything goes smoothly it will show up similar to the below output.

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

Nagios Configuration Summary

Nagios Core 4.4.9
Copyright (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 2022-11-16
License: GPL

Website: https://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

Step 10: Add Nagios Services to System Startup

To make Nagios work across reboots, we need to enable nagios and httpd at the system startup.

# systemctl enable nagios
# systemctl enable httpd

Next, restart Nagios to make the new settings take effect.

# systemctl restart nagios

Step 11: Allow Nagios Web in Firewall

To access the Nagios web interface, you need to open the Apache ports by running the following commands:

# firewall-cmd --permanent --zone=public --add-service=http
# firewall-cmd --permanent --zone=public --add-service=https
# firewall-cmd --reload

Step 12: Log in to the Nagios Web Interface

Your Nagios is ready to work, please open it in your browser with “ http://Your-server-IP-address/nagios ” or “ http://FQDN/nagios ” and Provide the username “nagiosadmin” and password.

Nagios Web Dashboard

Current Event Log

Congratulations! You've successfully installed and configured Nagios and its Plugins. You've just started your journey into monitoring.

References:

https://bbs.huaweicloud.com/blogs/313232
https://www.gingerdoc.com/nagios/nagios-core-install-arch-linux
https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/3/en/toc.html
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/security_guide/sect-security_guide-firewalls-basic_firewall_configuration
https://blog.csdn.net/liangpingguo/article/details/103941557

posted @ 2023-12-13 09:18  LandonXing  阅读(20)  评论(0)    收藏  举报