Nagios is a computer-software application that provides monitoring of all mission-critical infrastructure components including applications, services, operating systems, network protocols, systems metrics, and network infrastructure. Nagios offers to monitor and alerting services for servers, switches, applications and services.

This is a quick deployment and ready-to-run image.
Simple and rapid installation. Easy to maintain.

Guide – How To Start – Nagios: Network Monitoring System on Linux CentOS 8

1. To connect to the Server, you should generate a “Private Key” in advance. This can be done using the following instruction (by choosing the “file format:” option “.ppk” in point 3)

Guide – How To – Create and use Key Pair to connect to a VM

2. To connect to the virtual machine, you need to open port 80 (TCP) in the network properties in Security groups of the VM.

3. Use the program PuTTY (Download and run Putty) to work with the server

4. Go to SSH section then select Auth

5. In the “Auth” section, click “Browse” and specify the path to the .ppk file you received earlier.

6. Go to the home page of “Session”, enter the IP address of the VM and click “Open”.

7. In the opened console you will need to enter the login – centos

In the console, enter the following command:

> cat /credentials.txt

And in response, you will get the username и password to log in nagios.

8. After starting the VM, you can go to the admin panel. To do this, go to the following address http://*vm_ip*/nagios 

9. When you go to the site, a page with authorization will open.

10. Username to log in – “nagiosadmin” In the password field, enter the Instance ID of your VM

Also, the data is duplicated in the file / credentials.txt (to open it, you need to connect to the VM, how to do this you will find in the guideline below)

11. After entering your login information, you will be taken to the main page

Initially, the service is preset to check three hosts: localhost, 8.8.8.8 и yahoo.com 

To view the status of the hosts, you need to select Services or Host

If you have any questions, please refer to the main documentation – https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/4/en/toc.html

Writing host configs for monitoring – https://assets.nagios.com/downloads/nagioscore/docs/nagioscore/4/en/monitoring-publicservices.html

The main nagios directory is / usr / local / nagios /

Preset config for yahoo.com – /usr/local/nagios/etc/objects/yahoo.com.cfg

Preset config for 8.8.8.8 – /usr/local/nagios/etc/objects/8888.cfg

Main config file – /usr/local/nagios/etc/nagios.cfg