Nagios SNMP Plugins
			 ===================

What is it?
-----------

These are two plugins to be used with Nagios. They should still work
with NetSaint, but as this is now really ancient, I don't support
Netsaint any longer. You also need the Net SNMP Daemon in a reasonable
new version.

Nagios:   	http://www.nagios.org/
Net-SNMPD: 	http://www.net-snmp.org/


Who wrote it?
-------------

These programs are (C) 2002-2008 by
Henning P. Schmiedehausen

(C) 2010-2013 Elan Ruusamäe <glen@delfi.ee>

Distributed under GNU GENERAL PUBLIC LICENSE v2
(See file COPYING in the distribution).


Where to get it?
----------------

Homepage: https://github.com/glensc/nagios-snmp-plugins
Release downloads: https://github.com/glensc/nagios-snmp-plugins/releases

Acknowlegdements & Thanks
-------------------------

Elan Ruusamäe <glen at pld-linux.org>
   - enhanced reporting for the check_snmp_proc plugin. Also
     the only patch I ever got from a distribution vendor. :-)

Jose Pedro Oliveira <jpo at di.uminho.pt>

   - for maintaining the Fedora Extras RPM; I rolled a number of
   things from that spec file back into the "official" one.

Oliver Faenger <oliver.faenger at cityweb.de>
   - representing many many people who reported and sent me patches
     for the gcc4 compilation issue.

Mark Janssen <maniac at maniac.nl>
   - patch that displays the checked devices and processes

Henning P. Schmiedehausen
   - original code author


All the Linux distributions who included that little hack into their
package lists. BTW: I'd appreciate if you drop me a quick line when
you include nagios-snmp-plugins into a distribution. So far I know of:

- Fedora 7
- Fedora Extras
- PLD Linux


What can these plugins do?
--------------------------

NET-SNMP gives you an unique feature: It makes checks for running
processes and/or disk size configurable in the SNMP daemon and
queryable via SNMP. So you can do

proc  syslogd
proc  klogd

disk  /    5%
disk  /usr 10%


in your snmpd.local.conf and have the snmp daemon check that you
always have free space on your root and usr file system and that you
have syslogd and klogd processes running.

Querying this from a monitoring tool however, is very cumbersome. You
need to check what disks are there, then query error status.

These two plugins does all the work for you.


Where do the plugins run?
-------------------------

Well, on Linux. :-) That's where I wrote them. They should compile on
any other *x like Operating system, too. If you get them to compile,
please let me know.

I compiled and tested these plugins on

RedHat Linux 9
Fedora Core 1
Fedora Core 3
Fedora Core 4
Fedora Core 5
Fedora Core 6
RedHat Enterprise Linux 3
RedHat Enterprise Linux 4
RedHat Enterprise Linux 5
CentOS 5

using various nagios versions between 1.2 and 2.9.

Users reported success on various SuSE Linux and SLES
versions. Compilation on *BSD seems to be possible if you have a GNU
getline library.


How do I build and install?
---------------------------

- Unpack the distribution.

- Run

    aclocal
    autoheader
    automake --add-missing
    autoconf
    ./configure
    make

  or simply

    ./build.sh

- you should now have two binaries:  check_snmp_disk and check_snmp_proc

- copy them into your Nagios plugins directory.


How do I configure the plugins?
-------------------------------

Using Nagios there are two ways to configure the plugins:

The old way:

- add the following two lines to your /etc/nagios/command.cfg:

command[check_snmp_disk]=/usr/lib/nagios/plugins/check_snmp_disk -H $HOSTADDRESS$ -C $ARG1$
command[check_snmp_proc]=/usr/lib/nagios/plugins/check_snmp_proc -H $HOSTADDRESS$ -C $ARG1$

  Replace /usr/lib/nagios/plugins/ with the directory where you copied
  the binaries!

The new way:

- add the following lines to your /etc/nagios/checkcommands.cfg

# 'check_snmp_disk' command definition
define command	{
	command_name	check_snmp_disk
	command_line	$USER1$/check_snmp_disk -H $ARG1$ -C $USER3$
}


# 'check_snmp_proc' command definition
define command	{
	command_name	check_snmp_proc
	command_line	$USER1$/check_snmp_proc -H $ARG1$ -C $USER3$
}

- The Community password should be defined in your resources.cfg If you don't use
  $USER3$, adjust the definition above.


How do I use the plugins?
-------------------------

First, select something to check. You find a detailed description in
man snmpd.conf(5).

I, e.g. use (in /etc/snmpd/snmpd.local.conf under RedHat/Fedora):

#
# SNMP checked disks
#
disk	/		5%
disk	/usr		5%
disk	/var		10%
disk	/boot		1%
disk	/mnt/disk0	10%
#
# SNMP checked Processes
#
proc	crond
proc	ntpd
proc	sshd
proc	syslogd
proc	klogd

Which assures that all my disks do not fill up and that I have the
most important processes running on my boxes.

You need a configured snmpd with at least a read community configured.

Now try your configuration: Run the disk plugin manually:

check_snmp_disk -H <host to check> -C <community>

It should report either

"Checked <xxx> disks."  and a return code of 0 if everything is fine
(<xxx> should be the number of disks configured in the snmp.local.conf
file),

or

"<diskname>: less than <xxx>% free (= <yyy>%) (<devicename>)" and a
return code of 2 if there is a problem (diskname and devicename depend
on the disk, <xxx> is the threshold configured and <yyy> is the actual
free space).


The same testing can be done with the check_snmp_proc plugin.

Now configure your monitor program to monitor a host (in hosts.cfg):

The old way:

service[myhost]=DISK;0;24x7;3;5;1;admins;120;24x7;1;1;0;;check_snmp_disk!<community>
service[myhost]=PROC;0;24x7;3;5;1;admins;120;24x7;1;1;0;;check_snmp_proc!<community>

where <community is your read-community from above) and you're
set. The ";0;24x7;3;5;1;admins;120;24x7;1;1;0;;" parameters should be
of course your very own configuration. :-)

The new way:

# Service definition
define service	{
	use				generic-service

	host_name			myhost
	service_description		Disk Space
	check_command			check_snmp_disk!myhost
}

# Service definition
define service	{
	use				generic-service

	host_name			myhost
	service_description		Running processes
	check_command			check_snmp_proc!myhost
}

Of course you should replace "myhost" with your host.


What is left to do?
-------------------

- Hard/Soft Thresholds

- If multiple failures occur, only the first is reported
  (Nagios restriction) and every further error only when the
  first is fixed.


Release History
---------------

see NEWS FILE