Esto es una traducción y adaptación a inglés de mi proyecto final del grado superior de Administración de Sistemas Informáticos en Red, cursado en el instituto de Cuatrovientos entre 2014 y 2016. Me servirá para recordar este interesantísimo mundo de la monitorización del entorno TI y también para practicar el inglés. Espero que también sirva a alguien cara a empezar en el mundillo de Nagios.
This is the traduction and adaptation to English language of my final grade project, which is an introduction to mysteries of Nagios monitorization software and its functionality as well.
1. What is Nagios?
Nagios is a powerful monitorization tool, widely used in the enterprise area. It lets you supervise workstations, servers and other networking devices with their main services, as well as hardware values (CPU, RAM usage, CPU load, storage load, lets you know whether a port on your machine is opened) and services hosted by any particular machine: HTTP, SMTP, POP3, IMAP, FTP, etc.
When a host starts to behave in an abnormal way, Nagios is capable to notify this information to the responsible contact via different ways: E-mail, SMS message, instant messaging.
We can differ between Nagios Core, which is opesource and free and Nagios XI, which is not free, however is based on Nagios Core, superposing additional layers over the original application, extending its functionality, configuration and support of the software. One of its strong points is, with no doubt, the capability of configuration via web interface, whereas Nagios Core needs a manual config.
2. Which are the main functionalities of Nagios XI?
- Detect and respond in the fastest way when an IT failure occurs.
- Via advances statistics, anticipate the need of updating infrastructure before the systems start to fail.
- Coordinate the responses of the tech team.
- Being able to comply the SLA agreement.
- Monitorize efficiently and in a centralized way all of the enterprise infrastructure and assure the continuity of the business.
- Control complex infrastructures using distributed monitoring.
3. Nagios Core / Nagios XI comparison
4. First steps. Lab environment and Nagios installation
I'm going to create a small lab environment which is going to grow as we move along this "tutorial". I'm using VMware Workstation 14.1.2, build-8497320 if anyone's asking. You can use Oracle Virtualbox as an alternative. My virtual lab will consist of 2 virtual machines for now:
-CentOS 7 x64 VM, which is the recommended OS for Nagios Core installation.
-Windows 10 x64 VM, which is going to be a monitored host.
Both hosts are being configured in bridged mode, which means they will be able to access the internet, as well as my physical machine.
First we are going to complete CentOS 7 installation, which image can be downloaded on its official web page. I hope my readers already know how to complete that task.
Once operating systems are installed, we are going to perform Nagios Core installation on CentOS 7 VM.
Why Nagios Core and not XI if it's better?
I choose Nagios Core and not XI version, because along with the manual configuration, you are going to understand better how it works internally. It can be compared with learning Linux using GUI instead of learning to work with the Command line/Terminal.
When the installation is finished we are going to login with the root user. If the root password is not defined then you need to login with your regular user and define it manually.
Initially we don't have internet connection in our CentOS machine, as the interface configuration is no definded. We can see it performing a ping to a Google public DNS (8.8.8.8):
Let's see available network interfaces:
Once we've saved the config file, we are going to restart the network service in order to apply the changes:
And as we can see, we already configured successfully a static IP address on our Nagios machine, with Internet connection:
Now, from the Windows 10 VM we are going to see if there's any problem connecting with the Nagios server:
Now from the server to Windows 10 host:
If you're issuing any problems, make sure the network is bridged correctly (to a physical interface which has Internet connection). If you can't ping Windows machine try to disable the firewall on the VM or define the rule.
In the next chapter we are going to download, install Nagios Core and finally perform our very first check on our Win10 Workstation.
See you and hope you enjoyed the article!
