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Nagios Service Output Displays Random Numbers

Posted: Tue Jun 06, 2017 10:25 am
by tps27
Hey everyone!

I created a command on my nagios server to check hardware installed on remote hosts. The command_line is just: inxi -Fx

I installed inxi on the remote server, and the command runs in the service, providing the correct output. The issue is that the output included random number 12s.

For example, here is a line: 12System: 12Host ... 12Kernel 4.8.0-36-generic x86_64

Any suggestions on how to filter this out would be greatly appreciated!

Re: Nagios Service Output Displays Random Numbers

Posted: Tue Jun 06, 2017 2:41 pm
by dwhitfield
Can you post the script you are using, or a link to it? Thanks!

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 9:59 am
by tps27
Sure
commands.cfg:
# 'check_hardware_installed' command definition
define command{
command_name check_hardware_installed
command_line inxi -Fx
}

servers/host.cfg:
define host {
use linux-server
host_name host
alias Nagios Client 1
address IP
max_check_attempts 5
check_period 24x7
notification_interval 30
notification_period 24x7
}

define service {
use generic-service
host_name host
service_description PING
check_command check_ping!100.0,20%!500.0,60%
}

define service {
use generic-service
host_name host
service_description Hardware Check
check_command check_hardware_installed
}

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 11:10 am
by dwhitfield
What you've shown doesn't make a lot of sense. Are you using NRPE or NCPA or something else? Is the issue present when you also run the command locally to Nagios?

What version of Core are you using? Was it compiled from source or installed from distro repos? On what OS/version is nagios running? cat /etc/*-release may be of use.

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 11:17 am
by mcapra
Also, is inxi a command that refers to a Nagios plugin? Nagios isn't very good at taking arbitrary input from system commands (ipconfig, df -h, etc). It is very good at taking input from scripts that write to stdout and use unix error codes, though. Here's the guidelines for Nagios plugins in general:
https://nagios-plugins.org/doc/guidelines.html

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 11:20 am
by dwhitfield
Thanks @mcapra!

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 12:06 pm
by tps27
@dwhitfield I am using NRPE to run the inxi -Fx command on a remote host. I am using Nagios Core 4.2.0 on Ubuntu 16.04.2.

@mcapra Is just a package installed on Ubuntu. It is running via the command line. Are you recommending I create a script to run the command?

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 1:33 pm
by dwhitfield
Please show us the check_nrpe command you are running for Core along with the output.

Also, please show us the full output when you run inxi on the remote machine.

Please post your nrpe.cfg from the remote machine. Is the remote machine also Ubuntu 16.04.02?

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 2:39 pm
by tps27
Yes, the remote machine is also Ubuntu is also 16.04.2

Contents of nrpe.cfg file on remote machine:

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/nagios/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=10.105.42.157



# 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. Network addresses with a bit mask
# (i.e. 192.168.1.0/24) are also supported. Hostname wildcards are not currently 
# supported.
#
# 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=127.0.0.1,10.105.42.224
 


# 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=0



# BASH COMMAND SUBTITUTION
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments that contain bash command substitutions of the form
# $(...).  This option only works if the daemon was configured with both 
# the --enable-command-args and --enable-bash-command-substitution configure 
# script options.
#
# *** ENABLING THIS OPTION IS A HIGH SECURITY RISK! *** 
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow bash command substitutions, 
#         1=allow bash command substitutions

allow_bash_command_substitution=0



# 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=<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/lib/nagios/plugins/check_users -w 5 -c 10
command[check_load]=/usr/lib/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_hda1]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /dev/sda1
command[check_zombie_procs]=/usr/lib/nagios/plugins/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/lib/nagios/plugins/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/lib/nagios/plugins/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/lib/nagios/plugins/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/lib/nagios/plugins/check_disk -w $ARG1$ -c $ARG2$ -p $ARG3$
#command[check_procs]=/usr/lib/nagios/plugins/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$

#
# local configuration:
#	if you'd prefer, you can instead place directives here
include=/etc/nagios/nrpe_local.cfg

# 
# you can place your config snipplets into nrpe.d/
# only snipplets ending in .cfg will get included
include_dir=/etc/nagios/nrpe.d/
The output of inxi -Fx run from command line in the remote machine is:

Code: Select all

System:    Host: tim-SensuClient Kernel: 4.8.0-52-generic x86_64 (64 bit gcc: 5.4.0)
           Desktop: Unity 7.4.0 (Gtk 3.18.9-1ubuntu3.3)
           Distro: Ubuntu 16.04 xenial
Machine:   System: innotek (portable) product: VirtualBox v: 1.2
           Mobo: Oracle model: VirtualBox v: 1.2
           Bios: innotek v: VirtualBox date: 12/01/2006
CPU:       Single core Intel Core i7-3740QM (-UP-) cache: 6144 KB
           flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3) bmips: 5387 speed: 2693 MHz (max)
Graphics:  Card: InnoTek Systemberatung VirtualBox Graphics Adapter
           bus-ID: 00:02.0
           Display Server: X.Org 1.18.4 drivers: (unloaded: fbdev,vesa)
           Resolution: [email protected]
           GLX Renderer: Gallium 0.4 on llvmpipe (LLVM 3.8, 256 bits)
           GLX Version: 3.0 Mesa 12.0.6 Direct Rendering: Yes
Audio:     Card Intel 82801AA AC'97 Audio Controller
           driver: snd_intel8x0 ports: d100 d200 bus-ID: 00:05.0
           Sound: Advanced Linux Sound Architecture v: k4.8.0-52-generic
Network:   Card: Intel 82540EM Gigabit Ethernet Controller
           driver: e1000 v: 7.3.21-k8-NAPI port: d010 bus-ID: 00:03.0
           IF: enp0s3 state: up speed: 1000 Mbps duplex: full
           mac: 08:00:27:d4:26:d6
Drives:    HDD Total Size: 107.4GB (12.7% used)
           ID-1: /dev/sda model: VBOX_HARDDISK size: 107.4GB
Partition: ID-1: / size: 91G used: 5.3G (7%) fs: ext4 dev: /dev/sda1
           ID-2: swap-1 size: 8.49GB used: 0.00GB (0%) fs: swap dev: /dev/sda5
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   None detected - is lm-sensors installed and configured?
Info:      Processes: 165 Uptime: 5 min Memory: 907.5/7887.4MB
           Init: systemd runlevel: 5 Gcc sys: 5.4.0
           Client: Shell (bash 4.3.481) inxi: 2.2.35 

Re: Nagios Service Output Displays Random Numbers

Posted: Wed Jun 07, 2017 2:44 pm
by hsmith
NRPE might be running the command/script as a different user than you're running it as. The best thing you could do to troubleshoot is make sure you're running it as whatever NRPE is set up to run it as.

Edit: Looks like it's running as the 'nagios' user as indicated in your posted config file. Try to su to nagios and then run it.