Introduction In our previews article we walked you through installing nagios core on a Centos 7 system. In this article we will explain how to install Nagios plugins and the Nagios Remote Plugin Executor (NRPE) package. How does Nagios work? Nagios core runs from a central server which holds the configuration files. It runs active checks to monitor the state of services like HTTP and SSH, check if the server is up via ICMP and also monitor resource consumption like in the form of CPU load, memory utilization etc. The core server has a huge library of plugins and much of the functionality and flexibility of Nagios is derived from the use of these plugins. What are Nagios plugins? Plugins are compiled executable or scripts (Perl scripts, shell scripts, etc.) that can be run from a command line to check the status or a host or service. Nagios uses the results from plugins to determine the current status of hosts and services on your network. Nagios will execute a plugin whenever there is a need to check the status of a service or host. The plugin does something to perform the check and then simply returns the results to Nagios. It will process the results that it receives from the plugin and take any necessary actions. Installing Nagios plugins The plugins which provide the most commonly needed and used monitoring...Read More
Author: Sahil Suri
Introduction Nagios is an extremely popular open source monitoring and alerting tool. The name nagios is an offshoot of an older system called ‘net saint’. Although Nagios has it’s limits and is not an all in one solution but provides a considerable feature set nonetheless. The monitoring platform is available in two variants: Nagios core which is the open source and free variant and Nagios XI which is the enterprise version. In this article we will demonstrate step by step how to install the latest version of Nagios core on a Centos 7 system. Step 1: Install prerequisites for Nagios Nagios requires a web server like apache or nginx and it also requires php for some of its’ functionality. We will be installing Nagios from source and will therefore require some packages to help us compile Nagios core from source and install it. The dependencies could be installed using the following yum command. [ssuri@linuxnix:~] $ sudo yum install gcc glibc glibc-common gd gd-devel make net-snmp openssl-devel xinetd unzip -y Loaded plugins: langpacks, rhnplugin This system is receiving updates from RHN Classic or Red Hat Satellite. Package gcc-4.8.5-28.el7_5.1.x86_64 already installed and latest version Package glibc-2.17-222.el7.x86_64 already installed and latest version Package glibc-common-2.17-222.el7.x86_64 already installed and latest version Package gd-2.0.35-26.el7.x86_64 already installed and latest version Package 1:make-3.82-23.el7.x86_64 already installed and latest version Package 1:net-snmp-5.7.2-33.el7_5.2.x86_64 already installed and latest version Package unzip-6.0-19.el7.x86_64...Read More
Introduction In our earlier articles on package management for Debian bases distributions, we’ve covered dpkg, apt-get, and apt-cache tools. In this article, we will cover the apt tool for managing packages on our Ubuntu 16.04 system. The command line options for apt are very similar to those available with apt-get and apt-cache because apt encompasses features of both these tools into one package management tool. Apt is a front-end tool which works with dpkg in the background to maintain software on the system. To interact with the apt package manager, we use the apt command along with the appropriate options. We’ll now take you through some examples to help understand how we use the apt package manager. Example 1: Update local cache The system queries online remote and local repositories and maintains a cache of information about packages available in these repositories. This cache could be regarded as an index of available packages in the online repositories. The names and URLs of these online repositories are maintained in /etc/apt/sources.list file. Given below is a snippet from the file on my local system: root@linuxnix:~# cat /etc/apt/sources.list | grep -Ev '^#|^$|ec2' deb http://security.ubuntu.com/ubuntu xenial-security main restricted deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted deb http://security.ubuntu.com/ubuntu xenial-security universe deb-src http://security.ubuntu.com/ubuntu xenial-security universe deb http://security.ubuntu.com/ubuntu xenial-security multiverse deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse We can update that cache using the apt update command. Periodically updating the cache...Read More
Take this course
My name is Surendra Kumar Anne. I hail from Vijayawada which is cultural capital of south Indian state of Andhra Pradesh. I am a Linux evangelist who believes in Hard work, A down to earth person, Likes to share knowledge with others, Loves dogs, Likes photography. At present I work at Bank of America as Sr. Analyst Systems and Administration. You can contact me at surendra (@) linuxnix dot com.