Pablowe

Nagios Checks for HandlerSocket

I’ve written some new Nagios checks for HandlerSocket. check_handlersocket is a part of http://code.google.com/p/check-mysql-all/, and is meant to be called locally on the HandlerSocket server (usually via NRPE), but the perl-Net-HandlerSocket module must be installed. Feedback is welcome, usage is as follows:

More »

Knowing your PERC 6/i BBU

I’ve recently become supremely disappointed in the availability of Nagios checks for RAID cards. Too often, I see administrators rely on chance (or their hosting provider) to discover failed drives, a dying BBU, or a degrading capacity on their RAID cards. So I began work on check_raid (part of check_mysql_all) to provide a suite of checks. One of the first cards I wanted to support was the PERC 6/i, so I scoured the documentation, forums, and picked the brains of my friends before finally getting on a marathon 4 hour call with Dell support. I’ll now share the interesting things that I’ve learned.

More »

Nagios MySQL Plug-Ins

There currently exist many plugins for MySQL to use with Nagios. Many of them, however, are not version-independent, leaving organizations that use multiple versions of MySQL to either install multiple plugins or not monitor specific versions of MySQL. As such, I’ve compiled what I consider to be the most useful checks into a single plugin: check_mysql

Usage:
     check_mysql check_name [options]

     Options:
       --args|a     Optional arguments.  Comma-separated.  Check-specific.
       --critical|c The level at which a critical alarm is raised.  Check-specific.
       --database   The database to use (defaults to mysql)
       --help|?     Display this message and exit
       --hostname|H     The target MySQL server host (defaults to localhost)
       --password|p The password of the MySQL user
       --port       The port MySQL is listening on (defaults to 3306)
       --user|u     The MySQL user used to connect
       --version|V  Display version information and exit
       --warning|w  The level at which a warning is raised.  Check-specific.

     defaults are:

     ATTRIBUTE                  VALUE
     -------------------------- ------------------
     args                       No default value
     critical                   Check-specific
     database                   mysql
     help                       FALSE
     host                       localhost
     password                   No default value
     port                       3306
     timeout                    10 seconds
     user                       No default value
     verbose                    1 (out of 3)
     version                    FALSE
     warning                    Check-specific

Current Checks Supported:

* connect – Check to see whether or not one can connect to MySQL (USAGE)
* repl_io – Check to see whether on not the IO Replication thread is running (REPLICATION CLIENT)
* repl_sql – Check to see whether or not the SQL Replication thread is running (REPLICATION CLIENT)
* repl_sbm – Check how many seconds behind the master the slave is (REPLICATION CLIENT)
* mysql_query – Run a given query, test if it executes properly (SELECT)
* connections – Test if the percentage of used connections is over a given threshold (PROCESS)

I am open to requests for additional checks etc.

Nagios3 on CentOS: Quick Install Script

As part my job, I find myself doing Nagios installs on a somewhat regular basis. The following is a quick guide on installing Nagios 3 on CentOS, distilled from the official Nagios docs. It is meant to be copied and run as a shell script (you should only have to update the passwords):

#!/bin/sh

# Any Failing Command Will Cause The Script To Stop
set -e

# Treat Unset Variables As Errors
set -u

echo "***** Starting Nagios Quick-Install: " `date`
echo "***** Installing pre-requisites"
yum -y install httpd
yum -y install gcc
yum -y install glibc glibc-common
yum -y install gd gd-devel
yum -y install php

echo "***** Setting up the environment"
useradd -m nagios
echo "INSERT_PASSWORD_HERE" |passwd --stdin nagios
groupadd nagcmd
usermod -a -G nagcmd nagios
usermod -a -G nagcmd apache

echo "***** Getting the Nagios Source and Plug-Ins"
cd /usr/local/src
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.3.tar.gz
wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.15.tar.gz
tar xzf nagios-3.2.3.tar.gz
tar xzf nagios-plugins-1.4.15.tar.gz

echo "***** Installing Nagios"
cd /usr/local/src/nagios-3.2.3
./configure --with-command-group=nagcmd
make all
make install
make install-init
make install-config
make install-commandmode
make install-webconf

echo "***** Setting up htpasswd auth"
htpasswd -nb nagiosadmin INSERT_PASSWORD_HERE > /usr/local/nagios/etc/htpasswd.users
service httpd restart

echo "***** Setting up Nagios Plug-Ins"
cd /usr/local/src/nagios-plugins-1.4.15
./configure --with-nagios-user=nagios --with-nagios-group=nagios
make
make install

echo "***** Fixing SELinux"
chcon -R -t httpd_sys_content_t /usr/local/nagios/sbin/
chcon -R -t httpd_sys_content_t /usr/local/nagios/share/

echo "***** Starting Nagios"
chkconfig --add nagios
chkconfig nagios on
service nagios start

echo "***** Done: " `date`

Hope you find this useful!

* EDIT: 2011-02-17 – Added PHP as a prerequisite
* EDIT: 2010-12-22 – Updated link to get Nagios 3.2.3 & Nagios Plugins 1.4.15
* EDIT: 2009-09-07 – Updated link to get Nagios 3.2.0
* EDIT: 2009-10-14 – Updated link to get Nagios Plugins 1.4.14