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Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 7:27 am
by WillemDH
Hello,
Is it ok to install a nrpe agent on the Nagios server itself? I would like to check some things, like open files and load / cpu, but I'm not sure this is ok to do with NRPE?
Tx
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 7:59 am
by amybrown
It's already on there as part of the default install.
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 8:18 am
by WillemDH
Yes, I guessed so, but I have some bad experience with monitoring the monitoring server with it's own monitoring system.
The issue I first had was cause by don't blame nrpe parameter..
The other causes all deal with arguments. If you are passing arguments to the remote host through nrpe, the argument usage should
be consistent between the XI service check and the arguments declared in the command directive in the remote host's nrpe.cfg.
Additionally, Check the remote host's nrpe.cfg for the “dont_blame_nrpe” directive.
cat /usr/local/nagios/etc/nrpe.cfg | grep blame
The expected output should be:
dont_blame_nrpe=1
Without this directive set to “1”, arguments will not be accepted for any checks other than those specified in the nrpe.cfg file itself.
But now I get NRPE: Command 'check_xxx' not defined.. I can't find the commands in nrpe.cfg on the Nagios server, but I can't find it iether one a remote Linux server, where it does work..
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 8:25 am
by slansing
The nice thing about checking nagios locally is you do not need an agent, or NRPE to run the plugins since you are not remotely executing them, all you need to do is call the plugins locally.
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 8:53 am
by WillemDH
Sam,
Ok, I get that, but I can't seem to find for example the checks i showed in the screenshot of my post above.
I just noticed nrpe version of the Nagios server is 2.12 and nrpe on the remote Linux server is 2.14. Is this something we should upgrade manually?
grtz
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 9:06 am
by slansing
That is because you are trying to run NRPE checks locally and you probably do not have NRPE.cfg set up to take those commands, if you did want to do that, take a look at one of your remote nrpe.cfg files and copy it's command definitions over but in your case all you have to do is use your local plugins in "/usr/local/nagios/libexec" you do not need to use NRPE to call them.
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 9:35 am
by WillemDH
Sorry if I'm not clear.
But when I check the remote nrpe.cfg file I can't find the commands that do work at this moment. The commands in the above screenshot do work on the server with this nrpe.cfg:
# The following examples use hardcoded command arguments...
#command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10
#command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
#command[check_hda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
#command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z
#command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 150 -c 200
# The following examples allow user-supplied arguments and can
# only be used if the NRPE daemon was compiled with support for
# command arguments *AND* the dont_blame_nrpe directive in this
# config file is set to '1'. This poses a potential security risk, so
# make sure you read the SECURITY file before doing this.
#command[check_users]=/usr/local/nagios/libexec/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/local/nagios/libexec/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/local/nagios/libexec/check_disk -w $ARG1$ -c $ARG2$ -p $ARG3$
#command[check_procs]=/usr/local/nagios/libexec/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$
So I'm doing a check_mem on this remote server, but there seems to be no command?
Re: Monitoring Nagios server with NRPE
Posted: Wed Oct 02, 2013 9:45 am
by abrist
There is a good chance that your nrpe.cfg has a declaration for another config file. Could you post your nrpe.cfg file in entirety (in code wraps)?
Re: Monitoring Nagios server with NRPE
Posted: Thu Oct 03, 2013 1:54 am
by WillemDH
Sure, this is nrpe.cfg from /usr/local/nagios/etc from the remote Linux server:
Code: Select all
#############################################################################
# Sample NRPE Config File
# Written by: Ethan Galstad ([email protected])
#
# Last Modified: 11-23-2007
#
# NOTES:
# This is a sample configuration file for the NRPE daemon. It needs to be
# located on the remote host that is running the NRPE daemon, not the host
# from which the check_nrpe client is being executed.
#############################################################################
# LOG FACILITY
# The syslog facility that should be used for logging purposes.
log_facility=daemon
# PID FILE
# The name of the file in which the NRPE daemon should write it's process ID
# number. The file is only written if the NRPE daemon is started by the root
# user and is running in standalone mode.
pid_file=/var/run/nrpe.pid
# PORT NUMBER
# Port number we should wait for connections on.
# NOTE: This must be a non-priviledged port (i.e. > 1024).
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd
server_port=5666
# SERVER ADDRESS
# Address that nrpe should bind to in case there are more than one interface
# and you do not want nrpe to bind on all interfaces.
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd
#server_address=127.0.0.1
# NRPE USER
# This determines the effective user that the NRPE daemon should run as.
# You can either supply a username or a UID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd
nrpe_user=nagios
# NRPE GROUP
# This determines the effective group that the NRPE daemon should run as.
# You can either supply a group name or a GID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd
nrpe_group=nagios
# ALLOWED HOST ADDRESSES
# This is an optional comma-delimited list of IP address or hostnames
# that are allowed to talk to the NRPE daemon.
#
# Note: The daemon only does rudimentary checking of the client's IP
# address. I would highly recommend adding entries in your /etc/hosts.allow
# file to allow only the specified host to connect to the port
# you are running this daemon on.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd
allowed_hosts=127.0.0.1,<ip address Nagios server>
# COMMAND ARGUMENT PROCESSING
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments to commands that are executed. This option only works
# if the daemon was configured with the --enable-command-args configure script
# option.
#
# *** ENABLING THIS OPTION IS A SECURITY RISK! ***
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow arguments, 1=allow command arguments
dont_blame_nrpe=1
# COMMAND PREFIX
# This option allows you to prefix all commands with a user-defined string.
# A space is automatically added between the specified prefix string and the
# command line from the command definition.
#
# *** THIS EXAMPLE MAY POSE A POTENTIAL SECURITY RISK, SO USE WITH CAUTION! ***
# Usage scenario:
# Execute restricted commmands using sudo. For this to work, you need to add
# the nagios user to your /etc/sudoers. An example entry for alllowing
# execution of the plugins from might be:
#
# nagios ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/
#
# This lets the nagios user run all commands in that directory (and only them)
# without asking for a password. If you do this, make sure you don't give
# random users write access to that directory or its contents!
# command_prefix=/usr/bin/sudo
# DEBUGGING OPTION
# This option determines whether or not debugging messages are logged to the
# syslog facility.
# Values: 0=debugging off, 1=debugging on
debug=0
# COMMAND TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# allow plugins to finish executing before killing them off.
command_timeout=60
# CONNECTION TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# wait for a connection to be established before exiting. This is sometimes
# seen where a network problem stops the SSL being established even though
# all network sessions are connected. This causes the nrpe daemons to
# accumulate, eating system resources. Do not set this too low.
connection_timeout=300
# WEEK RANDOM SEED OPTION
# This directive allows you to use SSL even if your system does not have
# a /dev/random or /dev/urandom (on purpose or because the necessary patches
# were not applied). The random number generator will be seeded from a file
# which is either a file pointed to by the environment valiable $RANDFILE
# or $HOME/.rnd. If neither exists, the pseudo random number generator will
# be initialized and a warning will be issued.
# Values: 0=only seed from /dev/[u]random, 1=also seed from weak randomness
#allow_weak_random_seed=1
# INCLUDE CONFIG FILE
# This directive allows you to include definitions from an external config file.
#include=<somefile.cfg>
# INCLUDE CONFIG DIRECTORY
# This directive allows you to include definitions from config files (with a
# .cfg extension) in one or more directories (with recursion).
#include_dir=<somedirectory>
include_dir=/usr/local/nagios/etc/nrpe
# COMMAND DEFINITIONS
# Command definitions that this daemon will run. Definitions
# are in the following format:
#
# command[<command_name>]=<command_line>
#
# When the daemon receives a request to return the results of <command_name>
# it will execute the command specified by the <command_line> argument.
#
# Unlike Nagios, the command line cannot contain macros - it must be
# typed exactly as it should be executed.
#
#
# Note: Any plugins that are used in the command lines must reside
# on the machine that this daemon is running on! The examples below
# assume that you have plugins installed in a /usr/local/nagios/libexec
# directory. Also note that you will have to modify the definitions below
# to match the argument format the plugins expect. Remember, these are
# examples only!
# The following examples use hardcoded command arguments...
#command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10
#command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
#command[check_hda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/hda1
#command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z
#command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 150 -c 200
# The following examples allow user-supplied arguments and can
# only be used if the NRPE daemon was compiled with support for
# command arguments *AND* the dont_blame_nrpe directive in this
# config file is set to '1'. This poses a potential security risk, so
# make sure you read the SECURITY file before doing this.
#command[check_users]=/usr/local/nagios/libexec/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/local/nagios/libexec/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/local/nagios/libexec/check_disk -w $ARG1$ -c $ARG2$ -p $AR$
#command[check_procs]=/usr/local/nagios/libexec/check_procs -w $ARG1$ -c $ARG2$ -s $$
So as you can see, there is for example no check_mem in the config file. I must be missing something? Like for example check_mem, check_open_files, check_init_service
Re: Monitoring Nagios server with NRPE
Posted: Thu Oct 03, 2013 9:49 am
by lmiltchev
But when I check the remote nrpe.cfg file I can't find the commands that do work at this moment.
Look for a file named "common.cfg" on the remote box. It gets installed by our linux agent installer. You will find most of the commands defined there.
Hope this helps.