Unable to read output

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RDMaroto
Posts: 72
Joined: Wed Nov 20, 2013 10:54 am

Unable to read output

Post by RDMaroto »

Good morning.

On the Nagios server I execute:

./check_nrpe -H 10.2.25.129
NRPE v2.12

But when I execute the argument -c

[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.129 -c check_swap
NRPE: Unable to read output

My nrpe.cfg is:

Code: Select all

#############################################################################
# Sample NRPE Config File
# Written by: Ethan Galstad (nagios@nagios.org)
#
# 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=nrpe



# 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=nrpe



# 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=10.2.6.173,10.2.24.92,10.31.4.24


# 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/lib64/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=<someotherdirectory>



# 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/lib64/nagios/plugins/check_users -w 5 -c 10
command[check_users]=/usr/lib64/nagios/plugins/check_users -w $ARG1$ -c $ARG2$
command[check_load1]=/usr/lib64/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_load]=/usr/lib64/nagios/plugins/check_load -w $ARG1$ -c $ARG2$
#command[check_disk_root]=/usr/lib64/nagios/plugins/check_disk -l -w 10% -c 5%
command[check_disk_root]=/usr/lib64/nagios/plugins/check_disk -l -w $ARG1$ -c $ARG2$
command[check_swap1]=/usr/lib64/nagios/plugins/check_swap -w 20% -c 10%
command[check_swap]=/usr/lib64/nagios/plugins/check_swap -w $ARG1$ -c $ARG2$
#command[check_zombie_procs]=/usr/lib64/nagios/plugins/check_procs -w 40 -c 100 -s Z
command[check_zombie_procs]=/usr/lib64/nagios/plugins/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$
#command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w 300 -c 350
command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w $ARG1$ -c$ARG2$
#command[check_ssh]=/usr/lib64/nagios/plugins/check_ssh localhost
#command[check_http]=/usr/lib64/nagios/plugins/check_http -H localhost -I localhost

# 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/lib64/nagios/plugins/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/lib64/nagios/plugins/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/lib64/nagios/plugins/check_disk -w $ARG1$ -c $ARG2$ -p $ARG3$
#command[check_procs]=/usr/lib64/nagios/plugins/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$
-------------------------------
In remote machine
rpm -qa | grep openssl
openssl-1.0.1e-16.el6_5.14.x86_64

netstat -nap | grep 5666
(No info could be read for "-p": geteuid()=504 but you should be root.)
tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN -

ps -ef | grep nrpe | grep -v grep
4294967295 2975 1 0 Sep18 ? 00:01:35 nrpe -c /etc/nagios/nrpe.cfg -d

I have read that you can edit the sudoers, but in my case I do not run the commands with sudo

command[check_swap]=sudo /usr/lib64/nagios/plugins/check_swap -w 20% -c 10%

So I think that it should not be editing

Thanks for your time.
Regards
abrist
Red Shirt
Posts: 8334
Joined: Thu Nov 15, 2012 1:20 pm

Re: Unable to read output

Post by abrist »

The nrpe.cfg command specified expects arguments ($ARG1$ and $ARG2$) for the thresholds:

Code: Select all

command[check_swap]=/usr/lib64/nagios/plugins/check_swap -w $ARG1$ -c $ARG2$
In order to correctly invoke this command through nrpe, you need to specify the arguments:

Code: Select all

./check_nrpe -H 10.2.25.129 -c check_swap -w 20 -c 10
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RDMaroto
Posts: 72
Joined: Wed Nov 20, 2013 10:54 am

Re: Unable to read output

Post by RDMaroto »

Thanks for your reply abrist.

But I do not understand it
In my nrpe.cfg I have

command[check_users]=/usr/lib64/nagios/plugins/check_users -w $ARG1$ -c $ARG2$
command[check_load1]=/usr/lib64/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_load]=/usr/lib64/nagios/plugins/check_load -w $ARG1$ -c $ARG2$
#command[check_disk_root]=/usr/lib64/nagios/plugins/check_disk -l -w 10% -c 5%
command[check_disk_root]=/usr/lib64/nagios/plugins/check_disk -l -w $ARG1$ -c $ARG2$
command[check_swap1]=/usr/lib64/nagios/plugins/check_swap -w 20% -c 10%
command[check_swap]=/usr/lib64/nagios/plugins/check_swap -w $ARG1$ -c $ARG2$
#command[check_zombie_procs]=/usr/lib64/nagios/plugins/check_procs -w 40 -c 100 -s Z
command[check_zombie_procs]=/usr/lib64/nagios/plugins/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$
#command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w 300 -c 350
command[check_total_procs]=/usr/lib64/nagios/plugins/check_procs -w $ARG1$ -c$ARG2$
#command[check_ssh]=/usr/lib64/nagios/plugins/check_ssh localhost
#command[check_http]=/usr/lib64/nagios/plugins/check_http -H localhost -I localhost

On the nagios server:

[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.129 -c check_swap -a 20 10
NRPE: Unable to read output
[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.129 -c check_swap1
NRPE: Unable to read output
[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.129 -c check_load1
NRPE: Unable to read output

with another similar machine:

[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.126 -c check_swap1
NRPE: Command 'check_swap1' not defined
[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.126 -c check_swap -a 20 10
SWAP OK - 100% free (16383 MB out of 16383 MB) |swap=16383MB;0;0;0;16383


My problem is that 10.2.25.129 it does not interpret the argument - c

Thanks for your time.
Regards
RDMaroto
Posts: 72
Joined: Wed Nov 20, 2013 10:54 am

Re: Unable to read output

Post by RDMaroto »

with another similar machine:

[admin@sjcnagiosp01 libexec]$ ./check_nrpe -H 10.2.25.126 -c check_swap
check_swap: Warning threshold must be integer or percentage!
Usage:
check_swap [-av] -w <percent_free>% -c <percent_free>%
check_swap [-av] -w <bytes_free> -c <bytes_free>
User avatar
lmiltchev
Former Nagios Staff
Posts: 13587
Joined: Mon May 23, 2011 12:15 pm

Re: Unable to read output

Post by lmiltchev »

OK, let's focus on one nagios server and one client. :) Run the following command on the client (remote machine) and show us the output:

Code: Select all

grep "dont_blame_nrpe=" /usr/local/nagios/etc/nrpe.cfg
Note: Modify the path to the config if you need to.

1. Run the "check_nrpe" command on the nagios server from the command line, and show us the command and the output of it. Example:

Code: Select all

[root@testbox libexec]# ./check_nrpe -H 192.168.x.x -c check_swap_arg -a 20 10
SWAP OK - 99% free (1991 MB out of 2015 MB) |swap=1991MB;403;201;0;2015
2. Run the check locally (on the client) showing the full path to the plugin. Example:

Code: Select all

[root@speedking libexec]# /usr/local/nagios/libexec/check_swap -w 20 -c 10
SWAP OK - 99% free (1991 MB out of 2015 MB) |swap=1991MB;0;0;0;2015
3. Show us the command definition on the client. Example:

Code: Select all

command[check_swap_arg]=/usr/local/nagios/libexec/check_swap $ARG1$ $ARG2$
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RDMaroto
Posts: 72
Joined: Wed Nov 20, 2013 10:54 am

Re: Unable to read output

Post by RDMaroto »

Good morning
Thanks for your reply.

I disable the selinux in my remote machine and It works correctly
Thanks.
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