NAGIOS - VMware ESXi

This article describes how to monitor a VMWare ESXi or vSphere host with Nagios, using the OP5 Check ESX Plugin written in PERL. The plugin can monitor either a single ESXi/vSphere server or a VirtualCenter/vCenter Server and individual virtual machines. We’ll see here how to monitor an ESXi 4 host.
The following tutorial has been made on a CentOS server, you may have to adapt some paths with other distributions.

Installation

The prerequisite for the plugin to work is to install the VMWare Perl SDK available on the manufacturer website.
Download the file on your server, for example in the root directory, untar it and run the installer that way :

# cd /root # tar xvzf VMware-vSphere-Perl-SDK-4.1.0-254719.i386.tar.gz # cd vmware-vsphere-cli-distrib/ # ./vmware-install.pl

Follow the instructions given by the script. Depending on your setup, some PERL dependencies must be installed prior for the SDK to work correctly. When it’s done, we can get the plugin here, and copy it to/usr/lib/nagios/plugins/. Make it executable :

# cd /usr/lib/nagios/plugins/ # chmod a+x check_esx

Configuration

Now, we can start the real configuration for Nagios. We’ll need a username and password to access the ESXi host, let’s define those Nagios variables in a safe place in /etc/nagios/resource.cfg, so that this information will be hidden from the CGIs :

$USER11$=username $USER12$=password

In this tutorial, we’ll be monitoring these resources : CPU, memory usage, net usage, runtime status and IO/read/write. But some more are available, see the references here. Below are the new commands related to ESXi to add in the /etc/nagios/objects/command.cfg file (these are the ESXi related commands only, NOT the full command.cfg, you may append this at the end of the file) :

# check vmware esxi machine # check cpu define command{ command_name check_esx_cpu command_line $USER1$/check_esx -H $HOSTADDRESS$ -u $USER11$ -p $USER12$ -l cpu -s usage -w $ARG1$ -c $ARG2$ }   # check memory usage define command{ command_name check_esx_mem command_line $USER1$/check_esx -H $HOSTADDRESS$ -u $USER11$ -p $USER12$ -l mem -s usage -w $ARG1$ -c $ARG2$ }   # check net usage define command{ command_name check_esx_net command_line $USER1$/check_esx -H $HOSTADDRESS$ -u $USER11$ -p $USER12$ -l net -s usage -w $ARG1$ -c $ARG2$ }   # check runtime status define command{ command_name check_esx_runtime command_line $USER1$/check_esx -H $HOSTADDRESS$ -u $USER11$ -p $USER12$ -l runtime -s status }   # check io read define command{ command_name check_esx_ioread command_line $USER1$/check_esx -H $HOSTADDRESS$ -u $USER11$ -p $USER12$ -l io -s read -w $ARG1$ -c $ARG2$ }   # check io write define command{ command_name check_esx_iowrite command_line $USER1$/check_esx -H $HOSTADDRESS$ -u $USER11$ -p $USER12$ -l io -s write -w $ARG1$ -c $ARG2$ }

And an example of the configuration for a Nagios host called esxi01 in /etc/nagios/hosts/esxi01.cfg :

# Host esx01 define host{ use linux-server host_name esxi01 alias VMWare ESXi 01 address 192.168.1.100 }   # Define a service to "ping" the local machine define service{ use generic-service host_name esxi01 service_description PING check_command check_ping!100.0,20%!500.0,60% }   # VMWare # check cpu define service{ use generic-service host_name esxi01 service_description ESXi CPU Load check_command check_esx_cpu!80!90 }   # check memory usage define service{ use generic-service host_name esxi01 service_description ESXi Memory usage check_command check_esx_mem!80!90 }   # check net define service{ use generic-service host_name esxi01 service_description ESXi Network usage check_command check_esx_net!102400!204800 }   # check runtime status define service{ use generic-service host_name esxi01 service_description ESXi Runtime status check_command check_esx_runtime }   # check io read define service{ use generic-service host_name esxi01 service_description ESXi IO read check_command check_esx_ioread!40!90 }   # check io write define service{ use generic-service host_name esxi01 service_description ESXi IO write check_command check_esx_iowrite!40!90 }

It’s done. Restart Nagios and wait a while (or re-schedule) for the new resources to be monitored.