First Create a Command Definition inside Centreon that looks like this. Naturally alter the globals to fit inside your organisation.

Notice the Argument example, when you test it in this form you might also notice that you get a valid response from the server. Sadly this argument will not work inside the service definition.

Next Create a Service definition that utilizes this check command to check a specific counter. In my example i am using the MSExchange OWA\Total Users counter that is part of the new Exchange 2007 Perfmon counters. It will not work with a older exchange version. Use Perfmon on the destination machine to locate the right counters for your organisation.

Notice the difference in the passed Argument. To make this check command work you need to slightly alter the argument because the application is making the strings “save” when these settings are stored. The result is that some of the characters will be escaped. This can luckly be countered by participating this behavior.

We need the check_nrpe binairy to parse the escaped characters as literals and make centreon believe that we have already escaped the unsafe chars by adding slashes to each present slash, and add a double qoute at the start and the end to make check_nrpe binary parse the argument correctly. The outcome should look somewhat like this.

If this is the counter you want to check, and lets make it chalanging

\MSExchangeTransport Queues(_total)\Messages Queued For Delivery

Then the service argument for $ARG1$ in my example should look like this inside the Centreon service definition.

!\"\\MSExchangeTransport Queues(_total)\\Messages Queued For Delivery\"!(ARG2)!(ARG3)!

The result will be the following.

I hope this will help you tackle the “Counter” chalanges that Centreon will present when using the NSCLient++ and Check_NRPE commands.

Tools used in this setup

NSClient++ for Windows (32Bit / 64Bit) Using the NRPE option instead of the NS option.
http://nsclient.org/nscp/downloads

NSClient manual for Check_Counter
http://nsclient.org/nscp/wiki/CheckCounter

NSC.Ini file that we used on our remote machines (do add your nagios server IP to the allowed hosts section)
NSC.ini (Rename it by removing the .doc part or simply copy paste its contence)

Check_nrpe Command.
http://www.rpmfind.net/linux/rpm2html/search.php?query=check_nrpe

We’re using the provider Clickatell to send out SMS. To do the delivery, I wrote a PHP CLI (command line) script, which I’ll share here.  We use this script, to make Nagios (or Icinga, for that matter…) notify us via SMS about issues.

Pastebins

I also uploaded the script to pastebin.com and pastebin.ca, where you can “enjoy” the script with “nice” syntax highlighting It’s the same script at both pastebin.

Clickatell Documentation

• http://www.clickatell.com/downloads/http/Clickatell_HTTP.pdf
• View Online thanks to Google: http://docs.google.com/viewer?url=http://www.clickatell.com/downloads/http/Clickatell_HTTP.pdf

Required Parameters

The script REQUIRES the following parameters:

• -t → Phone number of the recipient (“to”).
  The script will strip out any non-digit characters from this parameter. So a good value might be: ‘+41 79 123 45 67′ or ‘41791234567′. The number MUST be specified in international format!
• -u → Clickatell Username
• -p → Clickatell Password
• -i → Clickatell API ID

The script will read the message text from standard input.

Optional Parameters

Additionally, there’s a handfull of OPTIONAL parameters:

• -@ → Scheduled Delivery Time. When should the message be sent?
  If not set, the message is sent “now”. Otherwise, it’ll be sent at (almost…) the given time. Format: Unix Timestamp (eg. 1233133393) or UTC date format (2009-01-30T14:00:00Z)
• -f → Source Address (“from”). Needs to be registered at Clickatell.
• -c → Max. number of concatted msgs to send out. By default, only 1 160char msg is send. If set to 2 or 3, 2x or 3x (160-7) char are allowed. Can be set to a higher value than 3, but shouldn’t.
• -b → Clickatell Callback type. See “5.2.4 Callback URL” of the Clickatell HTTP documentation. 0 = off, 3 = intermediate & final status
• -q → Required SMS Features. See “5.2.8 Required features” of the documentation. needs to incl. 16 if using Alpha (Text) as a “from” (-f) value.
• -x → Max. Credits; how many credits is ONE SMS message allowed to consum?; should be set to 3, to allow every possible SMS

Examples

echo 'Hello World!' | clickatell.php -t '+41 79 123 45 67' -u ClickDoe -p FooBar -i 9876543
clickatell.php -t 41791234567 -u ClickDoe -p FooBar -i 9876543 -@ 2009-12-24T18:00:00Z -f Santa-Claus -b 3 -x 3 -q 16 -c 3 < /tmp/msg

The first command will send the message “Hello World!” to +41 79 123 45 67. Clickatell username is set to ClickDoe and password is FooBar. At clickatell, a HTTP API has been registered and Clickatell assgined the number 9876543 to it.

The 2nd example reads a (possibly long) message from the file /tmp/msg. It’ll send out a maximum of 3x(16o-7) = 459 characters (because of the “-c 3” parameter) from the beginning of the message. The message is going to be send out at Christmas eve (“-@ 2009-12-24T18:00:00Z” ). It’s made to look like it’s from Santa (“-f Santa-Claus” — “Santa-Claus” needs to be registered at Clickatell first). One message can cost up to 3 credits (“-x 3” ) and required features is set to 16 (“-q 16” ), which means that a textual from (“Santa-Claus”) can be used.

Source

As mentioned, check out pastebin.com and pastebin.ca for nicely readable versions of the script.

#! /opt/csw/php5/bin/php
<?php

/*
 * Send SMS notifications using the Clickatell HTTP API Interface
 *
 * Description of command line parameters: see further down...
 *
 * Clickatell HTTP API Documentation:
 * http://www.clickatell.com/downloads/http/Clickatell_HTTP.pdf
 * -> http://docs.google.com/viewer?url=http://www.clickatell.com/downloads/http/Clickatell_HTTP.pdf
 */

// "Enhance" the implode() function to work with associative arrays (eg. array("user" => "john"))
function implode_assoc($array, $inner_glue = '=', $outer_glue = '&') {
 $output = array();
 foreach( $array as $key => $item )
 $output[] = $key . $inner_glue . $item;

 return implode($outer_glue, $output);
}

// Parse command line parameters
$args = getopt('t:u:p:i:@:f:b:c:q:x:');
if (
 ($args == FALSE)
 OR (! isset($args["t"]))
 OR (! isset($args["u"]))
 OR (! isset($args["p"]))
 OR (! isset($args["i"]))
){
 echo "Error! Command line arguments could not be parsed!

 * The script requires the following command line parameters:
 * # -t ['to' SMS Recipient Number - \$CONTACTPAGER\$] #
 * # -u [Clickatell Username] #
 * # -p [Clickatell Password] #
 * # -i [Clickatell API ID] #
 * -@ [Scheduled Delivery Time; When should the message be sent?; Formats: Unix timestamp (1233133393) or UTC date format (2009-01-30T14:00:00Z)]
 * -f ['from' Source Address A valid international format number between 1 and 16 characters long, or an 11 character alphanumeric string.]
 * -b [Clickatell Callback type; see 5.2.4 Callback URL (callback); 0 = off, 3 = intermediate & final status]
 * -c [Max. number of concatted msgs to send out. By default (1), only 1 160char msg is send. If set to 2 or 3, 2x or 3x (160-7) char are allowed]
 * -q [Required SMS Features; see 5.2.8 Required features (req_feat); needs to incl. 16 if using Alpha From]
 * -x [Max. Credits; how many credits is ONE SMS message allowed to consum?; should be set to 3, to allow every possible SMS]

 * Parameters listed with # are REQUIRED; others are optional.

 * The script reads the SMS text from STDIN, ie. invoke it like so:
 *   printf 'Hello\\nWorld!' | " . $_SERVER['SCRIPT_NAME'] . " -u JohnDoe -p FooBar -i 9876543 ...

 * Clickatell HTTP API Documentation:
 * http://www.clickatell.com/downloads/http/Clickatell_HTTP.pdf
 * -> http://docs.google.com/viewer?url=http://www.clickatell.com/downloads/http/Clickatell_HTTP.pdf
";
 exit(1);
}

echo "Welcome - Going to send an SMS....\n";

// "Fetch" parameters from the $args array
define('CLICKATELL_USER', $args['u']);
define('CLICKATELL_PASS', $args['p']);
define('CLICKATELL_API_ID', $args['i']);

// "Sanitize" the number of the recipient - ie. drop any non-digit char
define('TO', preg_replace('/[^[:digit:]]/', '', $args["t"]));

// Set "FROM"
if (isset($args['f'])){ define('FROM', $args['f']); }

// SMS Concatenation
// Maximum number of SMS to send, which makes up 1 msg at the
// receiver. Allows to send SMS messages which are longer than
// 160char
// See 5.2.6 Concatenation (concat)
if (isset($args['c'])){ define('SMS_CONCATS', $args['c']); }

// Callback Value
// See 5.2.4 Callback URL (callback)
//
//    Callback    Message status types returned                Message status code returned
//    value
//    0        No message status returned.
//    1        Returns only intermediate statuses.            002, 003, 011
//    2        Returns only final statuses of a message.        004, 005, 006, 007, 008, 010, 012
//    3        Returns both intermediate and final statuses of a msg.    All except 001
if (isset($args['b'])){ define('CALLBACK_VALUE', $args['b']); }

// Required Features
// See 5.2.8 Required features (req_feat)
//
//    Hex    Decimal    Feature        Description
//    0x0001    1    FEAT_TEXT    Text – set by default.
//    0x0002    2    FEAT_8BIT    8-bit messaging – set by default.
//    0x0004    4    FEAT_UDH    UDH (Binary) - set by default.
//    0x0008    8    FEAT_UCS2    UCS2 / Unicode – set by default.
//    0x0010    16    FEAT_ALPHA    Alpha source address (from parameter).
//    0x0020    32    FEAT_NUMER    Numeric source address (from parameter).
//    0x0200    512    FEAT_FLASH    Flash messaging.
//    0x2000    8192    FEAT_DELIVACK    Delivery acknowledgments.
//    0x4000    16384    FEAT_CONCAT    Concatenation – set by default.
if (isset($args['q'])){ define('REQ_FEAT', $args['q']); }

// Maximum Credits
// This parameter overrides the maximum charge associated with message delivery,
// 5.2.7 Maximum credits (max_credits)
if (isset($args['x'])){ define('MAX_CREDITS', $args['x']); }

// Scheduled Time
// The purpose of this parameter is to allow you to specify when you want a message to be delivered.
// See 5.2.16 Scheduled Time
// Formats:
//     1) Unix timestamp:
//         scheduled_time:1233133393
//     2) UTC date format:
//         scheduled_time:2009-01-30T14:00:00Z
if (isset($args['@'])){ define('SCHEDULED_TIME', $args['@']); }

// Read the to-be sent message from stdin.
$text = file_get_contents('php://stdin');
// Convert UTF-8 chars -> iso-8859-1
$text = utf8_decode($text);
// Only allow $concat_count * (160-7) chars in $text
if (defined('SMS_CONCATS')){
 $text = substr($text, 0, SMS_CONCATS * (160-7));
} else {
 $text = substr($text, 0, 160);
}

// URL to prepend to all outgoing calls
define('BASEURL', "http://api.clickatell.com");

// auth call
$cmd = "auth";
$cmd_parms = array("user" => CLICKATELL_USER, "password" => CLICKATELL_PASS, "api_id" => CLICKATELL_API_ID);
$url = BASEURL . "/http/" . $cmd . "?" . implode_assoc(array_map("urlencode", $cmd_parms));
// do auth call
$ret = file($url);
// split our response. return string is on first line of the data returned
$sess = split(":", $ret[0]);

// Did we get an "OK"? If so, continue with sending the message.
if ($sess[0] == "OK") {
 $sess_id = trim($sess[1]); // remove any whitespace
 $cmd = "sendmsg";
 $cmd_parms = array("session_id" => $sess_id,
 "to" => TO,
 "text" => $text
 );
 if (defined('MAX_CREDITS')){ $cmd_parms['max_credits'] = MAX_CREDITS; }
 if (defined('FROM')){ $cmd_parms['from'] = FROM; }
 if (defined('REQ_FEAT')){ $cmd_parms['req_feat'] = REQ_FEAT; }
 if (defined('CALLBACK_VALUE')){ $cmd_parms['callback'] = CALLBACK_VALUE; }
 if (defined('SMS_CONCATS')){ $cmd_parms['concat'] = SMS_CONCATS; }
 if (defined('SCHEDULED_TIME')){ $cmd_parms['scheduled_time'] = SCHEDULED_TIME; }

 $url = BASEURL . "/http/" . $cmd . "?" . implode_assoc(array_map("urlencode", $cmd_parms));
 // echo 'url: ' . $url . "\n";
 // exit(42);
 // do sendmsg call
 $ret = file($url);
 $send = split(":",$ret[0]);
 if ($send[0] == "ID") {
 echo "success
message ID: ". $send[1] . "\n";
 exit(0);
 } else {
 echo "send message failed: " . $ret[0] . "\n";
 exit(1);
 }
} else {
 echo "Authentication failure: " . $ret[0] . "\n";
 exit(2);
}

// We cannot reach this spot!
echo "ERROR! Impossible program location!";
exit(3);
// EOF //

Enjoy!

#FTW!

How to install Nagios.

SO today I decided to install and test nagios for testing purposes as its being used to monitor various services in the company I’m working in, surprisingly it was really simple…

I started by simply using the synaptic to locate and mark up nagios and click install, it installs apache but it doesn’t connect them.

then you test to see everything is ok by using

sudo nagios3 -v nagios.cfg

where nagios.cfg can be found in /etc/nagios3

the next step is creating nagios user and user group on the http server using

#htpasswd -c htpasswd.users nagios while in /etc/nagios3

which will create the file htpaswd.users which includes a user name and an encrypted password.

use a browser to log on to http://host_ip/nagios3 and you’ll be prompted for credentials, use the user name and password you just created.

you’ll find your self in the nagios interface but have access to nothing

Part 2: modify the configuration files

these files should be modified to reflect the current nagios configuration…to follow the instructions i started with the timeperiods_nagios2.cfg which can be foudn in conf.d directory which includes the time period definitions i just went through them to learn what each of them is, there are basically work hours/nonwork hours/24X7/and never

contacts_nagios2.cfg contains the contact people to recieve the emails

create group nagcmd if it wasn’t already created
then create user nagios
add users nagios and www-data to nagcmd group

grep nagios /etc/group to make sure they were created

i tried to open the http://host_ip/nagios3 and eventhough it opened and all i wasn’t able to view anything recieving It appears as though you do not have permission to view information for any of the hosts you requested… error

so i had to do something

i’m expecting that it has something to do with the htpasswd part

this took a while to solve but i finally found out that the default user name for nagios is infact nagiosadmin rather than nagios, and my installation somehow was inconsistent while file nagios.cfg had the main user as nagios, the cgi.cfg had the main user ans nagios admin. and of course the htpasswd.users had nagios, the solution was modifying the cgi.cfg to match the rest, simply by searching for and replacing nagios admin.

Part 3
now how to configure nagios to listen to services and check, first of all nagios places all the executable files in /usr/lib/nagios/plugins/ these files are used to check the services. you can of course develop your own, but i didnt try that yet.

now you go to /etc/nagios-plugins/config this contain the config files that calls on these executables, you can configure here.

then another important file is hostname_nagios2.cfg which actually contains the monitored services, you define the thresholds here.

Part 4

another important note, to actually allow modifying nagios from the web interface you need to tweak the
nagios.cfg, firts the command_file variable should point to an empty file named anything (and you have to create it) the commands are kept there till the nagios reads them. and then log_external_commands should be set to 1.

#/etc/init.d/nagios3 restart

UPDATE

I restarted the nagios service and for some reason it didn’t start I checked the log to find out that the service wasn’t able to create the cmd file (the one talked about earlier) I deleted the file and tried to restart again and got the same result, obviously the nagios user didnt have write access to that folder, and after chmoding the folder it worked out perfectly.

Yey!

yeah, i have luckily become a tester for the new Nagios XI (eXtended Interface) tool and I thought…. Lets devote a post to this new product!

Well first i was a bit surprised that the new product comes as a VM package meaning that you will download a virtual machine with all the required settings pre-configured for you. When reading various posts on the subject, its all support related, which brings me to the second point. Nope, Nagios XI will not be open source as in “free for download”, but it will be open source as in “your free to develop ontop of the original product”.

Yea i know this will raise allot of questions, but drilling down to the source of this ‘little evil’ it seems that developers need to be payed, so lets blame society for this and not the people developing and releasing the product.

What does it do?
Well the Nagios-Core (which is and stays free for download) monitors network nodes using check_commands that can be utilized by nagios to check for a wide range of network services like; Ping,Oracle,NTP,DHCP,CPU,MEM,DISKSpace.

Using the data the Nagios-Core collects there are a wide range of exsisting GUIs that can make this data visible in many different ways like; headsup-displays,performance-graphs,traffic-lights etc. And allows people to be notified using mail,sms,or other means.

Whats XI?
Well most of the GUIs had a mayor downside, it required a fair amount of know how to get it up and running. You needed to compile allot of tar-bals, install allot different RPMs and next you needed to make all these different things work together using some kind of a unified configuration that could reach 1M lines easily when you wanted all the fancy features.

Nagios-XI primarily makes the nagios tool and its GUI available for non-skilled users that dont have any affinity with linux. Its a VMware image that you can boot easily using a VMware player. Next thing you need to do is configure an IP (with extended manual) and open your explorer. The rest is done from there, pre-configured and working without a hassle.

Next to that the GUI is fully graphical including configuration wizards, custom dashboards (drag-drop style), custom views, custom almost everything. In short, Next, Next, Finish!

Im not sure seasoned engineers like myself would buy this product quickly, most of us would compile, configure, and download a GNU gui and work from there. But i do think there is a large market out there of engineers that dont have the required time, or linux know-how to get up and running. For these people i think Nagios XI will be a welcome alternative!

Rgrds,

Amazon Web Services released it’s  CloudWatch API and many people are using it to gather metrics/information about their servers. This article describes the process used to write a nagios compatible plugin that gathers data from the Amazon CloudWatch API. We decided to write this plugin in a nagios compatible mode because nagios is basically the defacto standard in monitoring return code.

Background

This plugin was written for DartWare’s InterMapper as a probe pack for it’s Free 5 Server Cloud Monitoring solution. More information about DartWare’s monitoring solutions in and out of the cloud can be found at: http://intermapper.com

Almost all network monitoring solutions support nagios compatible scripts including InterMapper. InterMapper is an extremely versatile network and system monitoring solution. This plugin returns all nagios compatible messages and furthermore uses InterMapper formatting when nagios is not specifically set to true.

What do I need to make this plugin work?

The CloudWatch monitoring plugin is written in Python and relies on the BOTO framework. The BOTO framework is included with the download at the bottom of the page.

Examples

The following execution of the CloudWatch Script will give you CPU utilization for a specific InstanceID. The options -w and -c represent the warning and critical thresholds within nagios.

CPUUtilization

The warning and critical thresholds are measured in percent.

./awscloudwatch.py -a <access-key> -s <secrect-key> -i <instance-id> -m CPUUtilization -w 10 -c 70

NetworkIn

The warning and critical thresholds are measured in bytes/sec.

./awscloudwatch.py -a <access-key> -s <secrect-key> -i <instance-id> -m CPUUtilization -w 10000 -c 900000

Results Look Like?

By default all info messages are displayed with InterMapper’s  probe formatting, this allows InterMapper users to track detailed information and make it graphable.

\{ $CPUUtilization := “2.78″ }

To get standard nagios INFO messages just pass “–nagios True”  and the response will look more like:

OK: CPUUtilization is 2.73

What other metrics are supported?

Currently all of CloudWatch metrics can be monitored. Please see the following API document for all available metrics and their data types.

http://docs.amazonwebservices.com/AmazonCloudWatch/latest/DeveloperGuide/arch-AmazonCloudWatch-metricscollected.html

Download The Plugin Now

The CloudWatch plugin can be downloaded by clicking here . To learn more about how InterMapper’s free custom AWS AMI visit here

*THIS POSITION HAS CLOSED.  THANK YOU FOR YOUR INTEREST.*

Our client’s growing their Technical Operations team to meet the demands of their rapidly growing user community, and have a terrific opportunity for a DATA CENTER ADMINISTRATOR with strong attention to detail and excellent communication skills. This position is primarily onsite at local data centers, with occasional onsite work in their Oakland, CA offices, and travel to remote data center locations a few times per year. Our client’s team is small, agile and dedicated.  They value diligence and creativity in scaling our infrastructure while consolidating servers as our usage continues to grow.  We are  looking for the right person for this position – someone who’s ready to dig in on day one, with substantial hands-on experience in data centers and a “can-do” attitude.

RESPONSIBILITIES

As a member of our client’s Technical Operations team, you will have primary responsibility for the daily operations of our SAN JOSE, CA and SAN FRANCISCO, CA co-location data centers. Primarily on site in San Jose, you will be the eyes, ears and hands for our client’s team there – coordinating everything from rack mounting servers, performing routine maintenance and hardware troubleshooting to structured cable design, operating system installs, cross-connect installs, vendor deliveries and physical plant maintenance.

REQUIREMENTS

You must be self-motivated, capable of managing your time well, and work efficiently without close supervision. Meticulous and well-documented work is an absolute must. You should be enthusiastic about hardware and cabling installation, diagnostics, and repair. You will be responding to trouble tickets opened by staff members but will also be expected to proactively identify and resolve problems as you gain familarity with our client’s systems.

• 5 years extensive PC Hardware experience and detailed knowledge of components (x86, x86_64 with a strong preference for white/grey box systems)
• Minimum 5 year hands-on UNIX/Linux experience, including solid knowledge of OS install, configuration, and boot
• Experience working in a 24/7 customer-facing environment
• Experience building & maintaining structured cabling
• Strong experience with host-based storage & RAID
• Strong understanding of ethernet networking & TCP/IP
• Reliable transportation between Oakland, San Jose,  and San Francisco (available as needed, 24/7)
• Be able to lift 50lb to a height of 6ft
• Available for occasional off-hours (24/7) on-site data center support

DESIRED SKILLS

• Experience with Debian or Ubuntu
• Experience with enterprise switches (Cisco, Force10, Arista, Foundry)
• Understanding of Load Balancers
• Familiarity with optical networks
• Scripting in BASH, Perl and/or Python
• System monitoring (Nagios, Cacti, Smokeping)
• Understanding of DHCP, PXE and automated system installs

If you are interested, please send us your resume to tsotelo@mindsource.com.

Required Packages

Make sure you’ve installed the following packages on your Ubuntu installation before continuing.

• Apache 2
• PHP
• GCC compiler and development libraries
• GD development libraries

You can use apt-get to install these packages by running the following commands:

sudo apt-get install apache2

sudo apt-get install libapache2-mod-php5

sudo apt-get install build-essential

With Ubuntu 6.10, install the gd2 library with this command:

sudo apt-get install libgd2-dev

With Ubuntu 7.10, the gd2 library name has changed, so you’ll need to use the following:

sudo apt-get install libgd2-xpm-dev

1) Create Account Information

Become the root user.

sudo -s

Create a new nagios user account and give it a password.

/usr/sbin/useradd -m -s /bin/bash nagios

passwd nagios

On older Ubuntu server editions (6.01 and earlier), you will need to also add a nagios group (it’s not created by default). You should be able to skip this step on desktop, or newer server editions of Ubuntu.

/usr/sbin/groupadd nagios

/usr/sbin/usermod -G nagios nagios

Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.

/usr/sbin/groupadd nagcmd

/usr/sbin/usermod -a -G nagcmd nagios

/usr/sbin/usermod -a -G nagcmd www-data

2) Download Nagios and the Plugins

Create a directory for storing the downloads.

mkdir ~/downloads

cd ~/downloads

Download the source code tarballs of both Nagios and the Nagios plugins (visit http://www.nagios.org/download/ for links to the latest versions). These directions were tested with Nagios 3.1.1 and Nagios Plugins 1.4.11.

wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.0.tar.gz

wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz

3) Compile and Install Nagios

Extract the Nagios source code tarball.

cd ~/downloads

tar xzf nagios-3.2.0.tar.gz

cd nagios-3.2.0

Run the Nagios configure script, passing the name of the group you created earlier like so:

./configure --with-command-group=nagcmd

Compile the Nagios source code.

make all

Install binaries, init script, sample config files and set permissions on the external command directory.

make install

make install-init

make install-config

make install-commandmode

Don’t start Nagios yet – there’s still more that needs to be done…

4) Customize Configuration

Sample configuration files have now been installed in the /usr/local/nagios/etc directory. These sample files should work fine for getting started with Nagios. You’ll need to make just one change before you proceed…

Edit the /usr/local/nagios/etc/objects/contacts.cfg config file with your favorite editor and change the email address associated with the nagiosadmin contact definition to the address you’d like to use for receiving alerts.

vi /usr/local/nagios/etc/objects/contacts.cfg

5) Configure the Web Interface

Install the Nagios web config file in the Apache conf.d directory.

make install-webconf

Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account – you’ll need it later.

htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Restart Apache to make the new settings take effect.

/etc/init.d/apache2 reload

Note: Consider implementing the ehanced CGI security measures described here to ensure that your web authentication credentials are not compromised.

6) Compile and Install the Nagios Plugins

Extract the Nagios plugins source code tarball.

cd ~/downloads

tar xzf nagios-plugins-1.4.11.tar.gz

cd nagios-plugins-1.4.11

Compile and install the plugins.

./configure --with-nagios-user=nagios --with-nagios-group=nagios

make

make install

7) Start Nagios

Configure Nagios to automatically start when the system boots.

ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios

Verify the sample Nagios configuration files.

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

If there are no errors, start Nagios.

/etc/init.d/nagios start

Login to the Web Interface

You should now be able to access the Nagios web interface at the URL below. You’ll be prompted for the username (nagiosadmin) and password you specified earlier.

http://localhost/nagios/

Click on the “Service Detail” navbar link to see details of what’s being monitored on your local machine. It will take a few minutes for Nagios to check all the services associated with your machine, as the checks are spread out over time.

9) Other Modifications

If you want to receive email notifications for Nagios alerts, you need to install the mailx (Postfix) package.

sudo apt-get install mailx

sudo apt-get install postfix

You’ll have to edit the Nagios email notification commands found in /usr/local/nagios/etc/objects/commands.cfg and change any ‘/bin/mail’ references to ‘/usr/bin/mail’. Once you do that you’ll need to restart Nagios to make the configuration changes live.

sudo /etc/init.d/nagios restart

Configuring email notifications is outside the scope of this documentation. Refer to your system documentation, search the web, or look to the Nagios Support Portal or Nagios Community Wiki for specific instructions on configuring your Ubuntu system to send email messages to external addresses.

Aqui ficam dois tutoriais de configuração para o Nagios.
Para aqueles que não sabem o que é, o Nagios é um software opensource de monitorização de serviços e equipamentos de rede. Podendo alertar os administradores sobre problemas nos serviços, bem como problemas dos próprios equipamentos.

1. Download the Nagios Power Supply check for PowerEdge 1850 from Nagios Exchange:

http://exchange.nagios.org/directory/Plugins/Hardware/Server-Hardware/Dell/Check-Dell-server-power-supplies-status/details

wget http://exchange.nagios.org/components/com_mtree/attachment.php?link_id=437&cf_id=24

2.The command line options and instructions on how to implement the check are listed on the plugin site.

3.  For each server, I needed to play with the command line options.  For most servers, the options of -n 2 -c 2 (2 – power supplies and 2 cpus) worked just fine, but for some servers I needed to edit those.  For one server particularly I needed to not provide any options.

4. This got Nagios checks working for all PowerEdge 1850’s.  But we had some 770N,  2650, and 850’s in our environment as well.

5. First make a copy so you can change the OID’s as appropriate.

6. I downloaded the MIB table from Dell for the PowerEdge 850.  From searching through the table I found a PowerSupplyStatus OID of  .1.3.6.1.4.1.674.10892.1.600.12.1.5  I edited the original script and change the powersupply OID from .1.3.6.1.4.674.10892.1.600.12.1.10.1 to .1.3.6.1.4.674.10892.1.600.12.1.5.1

7. Test the script via command line to find the appropriate values for the number of power supplies -n and the number of CPU’s. For some hosts I wasn’t able to enter a CPU value, it only worked with a number for the power supplies.

./check_snmp_dell_powersupply_other.pl -H IPAddress -C CommunityString -n 2

./check_snmp_dell_powersupply_other.pl -H 128.97.154.177 -C Jum73guG -n 1 -c 1

8. Enter into the commands.cfg the correct command definition and edit the powersupply.cfg file to add the service for the new servers.

I have a friend who works for an ISP and a few months back he told me about how he had wrangled Nagios into monitoring their servers and networking equipment. His story piqued my interest, and last night I finally downloaded Nagios, and configured it to monitor my 24×7 Linux host that sits behind my TV providing a number of different services to my internal network. Installing Nagios from source was simple with the instructions at http://www.nagios.org, and within minutes I was up and running. I had a little trouble with setting up auth_digest authentication for apache2 but I think that was mostly because that module wasn’t enabled by default. After I got the main configuration up and running, and I was able to access the web interface, I began to poke around. While I was doing this I got an email notification that my disk space was over 20%. I then thought, wouldn’t this be cool if I could turn this into a push notification?
I already set up a script provided by http://prowl.weks.net/static/prowl.pl, and have that working to notify me when a new TV show is added to my Linux host. I found that the settings for notifications in Nagios were located at /usr/local/nagios/etc/objects/commands.cfg. In the notifications section, I added the following below the two entries for email notifications, which I included:

# ‘notify-host-by-email’ command definition
define command{
command_name notify-host-by-email
command_line /usr/bin/printf “%b” “***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\nHost: $HOSTNAME$\nState: $HOSTSTATE$\nAddress: $HOSTADDRESS$\nInfo: $HOSTOUTPUT$\n\nDate/Time: $LONGDATETIME$\n” | /usr/bin/mail -s “** $NOTIFICATIONTYPE$ Host Alert: $HOSTNAME$ is $HOSTSTATE$ **” $CONTACTEMAIL$
}

# ‘notify-service-by-email’ command definition
define command{
command_name notify-service-by-email
command_line /usr/bin/printf “%b” “***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\n\nService: $SERVICEDESC$\nHost: $HOSTALIAS$\nAddress: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$SERVICEOUTPUT$” | /usr/bin/mail -s “** $NOTIFICATIONTYPE$ Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **” $CONTACTEMAIL$
}

# ‘notify-host-by-prowl’ command definition
define command{
command_name notify-host-by-prowl
command_line /usr/local/bin/prowl.pl -application=”Nagios” -event=”** $NOTIFICATIONTYPE$ Host Alert: $HOSTNAME$ is $HOSTSTATE$ **” -notification=”Host: $HOSTNAME$ State: $HOSTSTATE$ Address: $HOSTADDRESS$ Info: $HOSTOUTPUT$ Date/Time: $LONGDATETIME$” -priority=1 -apikey=THISISWHEREMYAPIKEYWOULDGO
}

# ‘notify-service-by-prowl’ command definition
define command{
command_name notify-service-by-prowl
command_line /usr/local/bin/prowl.pl -application=”Nagios” -event=”** $NOTIFICATIONTYPE$ Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **” -notification=”Host: $HOSTNAME$ State: $HOSTSTATE$ Address: $HOSTADDRESS$ Info: $HOSTOUTPUT$ Date/Time: $LONGDATETIME$” -priority=1 -apikey=THISISWHEREMYAPIKEYWOULDGO
}

So now, when Nagios sends a notification, I get a pop up instantly on my phone that looks something like this:

Nagios iPhone Prowl

Righteous!!