- 1 About Nagios
- 2 Prerequisites
- 3 Create Nagios User And Group
- 4 Download necessary software
- 5 Install Nagios And Plugins
- 6 Access Nagios Web Interface
- 7 Possible issues
- 8 Reference Links:
Nagios is an enterprise class, open source software that can be used for network and infrastructure monitoring. Using Nagios, we can monitor servers, switches, applications and services etc. It alerts the System Administrator when something goes wrong and also alerts back when the issues have been rectified.
Using Nagios, you can:
- Monitor your entire IT infrastructure.
- Identify problems before they occur.
- Know immediately when problems arise.
- Share availability data with stakeholders.
- Detect security breaches.
- Plan and budget for IT upgrades.
- Reduce downtime and business losses.
Make sure your server have installed with fully working LAMP stack. If not, follow the below link to install LAMP server.
Then install the following prerequisites:
apt-get install build-essential libgd2-xpm-dev apache2-utils unzip curl a2enmod rewrite a2enmod cgi
Create Nagios User And Group
Create a new nagios user account:
useradd -m nagios passwd nagios
Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.
groupadd nagcmd usermod -a -G nagcmd nagios usermod -a -G nagcmd www-data
Download necessary software
Go to the nagios download page, and get the latest version. As of writing this, the latest version was 4.1.1.
wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.1.1.tar.gz -O /usr/src/nagios-4.1.1.tar.gz
Download nagios plugins too. Nagios plugins allow you to monitor hosts, devices, services, protocols, and applications with Nagios
wget http://www.nagios-plugins.org/download/nagios-plugins-2.1.1.tar.gz -O /usr/src/nagios-plugins-2.1.1.tar.gz
Install Nagios And Plugins
Go to the folder where you’ve downloaded nagios (/usr/src), and extract it using command:
cd /usr/src tar xzf nagios-4.1.1.tar.gz
Change to the nagios directory:
Run the following commands one by one from the Terminal to compile and install nagios.
./configure --with-nagios-user=nagios --with-nagios-group=nagcmd --with-openssl
make all make install make install-init make install-config make install-commandmode
Install Nagios Web interface
Enter the following commands to compile and install nagios web interface.
You may get the following error:
/usr/bin/install -c -m 644 sample-config/httpd.conf /etc/httpd/conf.d/nagios.conf /usr/bin/install: cannot create regular file ‘/etc/httpd/conf.d/nagios.conf’: No such file or directory Makefile:296: recipe for target 'install-webconf' failed make: *** [install-webconf] Error 1
The above error message describes that nagios is trying to create the nagios.conf file inside the /etc/httpd.conf/directory. But, in Ubuntu systems the nagios.conf file should be placed in /etc/apache2/sites-enabled/directory.
So, run the following command instead of using make install-webconf.
/usr/bin/install -c -m 644 sample-config/httpd.conf /etc/apache2/sites-enabled/nagios.conf
Check if nagios.conf is placed in /etc/apache2/sites-enabled directory.
ls -l /etc/apache2/sites-enabled/
total 4 lrwxrwxrwx 1 root root 35 oct 5 2015 000-default.conf -> ../sites-available/000-default.conf -rw-r--r-- 1 root root 1679 abr 11 13:32 nagios.conf
Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account. You’ll need it while logging in to nagios web interface..
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Restart Apache to make the new settings take effect.
systemctl restart apache2
Install Nagios plugins
Go to the directory where you downloaded the nagios plugins (/usr/src), and extract it.
cd /usr/src tar xzf nagios-plugins-2.1.1.tar.gz
Change to the nagios plugins directory:
Run the following commands one by one to compile and install it.
./configure --with-nagios-user=nagios --with-nagios-group=nagcmd make make install
Check Nagios and generate Init Script
Check nagios,conf file for any syntax errors:
/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
Create the Init Script copying /etc/init.d/skeleton to /etc/init.d/nagios using the following command:
cp /etc/init.d/skeleton /etc/init.d/nagios
Edit file /etc/init.d/nagios:
Add the following lines:
DESC="Nagios" NAME=nagios DAEMON=/usr/local/nagios/bin/$NAME DAEMON_ARGS="-d /usr/local/nagios/etc/nagios.cfg" PIDFILE=/usr/local/nagios/var/$NAME.lock
Save and close the file.
Finally you need to change the permissions of the file
chmod +x /etc/init.d/nagios
Now, you can start nagios service using command:
/etc/init.d/nagios start ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios
Access Nagios Web Interface
Open up your web browser and navigate to http://nagios-server-ip/nagios and enter the username as nagiosadmin and its password which we created in the earlier steps.
If you have an error with PING checks “Could not interpret output from ping command” apply this fix:
chmod u+s /bin/ping
I know my strengths and weaknesses. I'm a quick learner, I know how to work with small and big teams. I'm hard worker, proactive and I achieve everything I propose.
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