check_nrpe!check_load command failed

[mishomor]

Here it comes

#############################################################################
# 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=184.x.x.x



# 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=127.0.0.1,54.x.x.x



# 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



# 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/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/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 $ARG3$

[slansing]

Aha! There is the problem, see, near the bottom your nrpe.cfg file shows it's internal command definitions, these are what nagios talks to, to get NRPE to execute remote plugins, such as check_load. Try your Nagios check command without anything after -a specified, including -a itself. Since there are no argument slots defined in the NRPE.cfg the nagios command we are running is throwing extra nonsense at the remote NRPE that it expects it to pass. Which is not the case since a -w and -c are already stated as hard code, which we can change later. Lets first make sure this works.

[mishomor]

Aha! There is the problem, see, near the bottom your nrpe.cfg file shows it's internal command definitions, these are what nagios talks to, to get NRPE to execute remote plugins, such as check_load. Try your Nagios check command without anything after -a specified, including -a itself. Since there are no argument slots defined in the NRPE.cfg the nagios command we are running is throwing extra nonsense at the remote NRPE that it expects it to pass. Which is not the case since a -w and -c are already stated as hard code, which we can change later. Lets first make sure this works.

--With -a
# /usr/local/nagios/libexec/check_nrpe -H test -c check_load -a
/usr/local/nagios/libexec/check_nrpe: option requires an argument -- 'a'

--without a
# /usr/local/nagios/libexec/check_nrpe -H test -c check_load
NRPE: Unable to read output

[mishomor]

Since we enabled dont_blame_nrpe=1, shouldn't we uncomment last set of commands and comment section above?

[slansing]

You could do so, but I would change:

Code: Select all

command[check_load]=/usr/local/nagios/libexec/check_load -w $ARG1$ -c $ARG2$

To:

Code: Select all

command[check_load]=/usr/local/nagios/libexec/check_load $ARG2$

Since in nagios you are passing -w -c values in ARG2.

If you call the check_load plugin locally on the remote host what is returned?:

Code: Select all

/usr/local/nagios/libexec/check_load

[mishomor]

I changed command as suggested and got same error
#/usr/local/nagios/libexec/check_nrpe -H test -c check_load
NRPE: Unable to read output

Client log
Sep 27 22:50:42 test xinetd[21286]: xinetd Version 2.3.14 started with libwrap loadavg labeled-networking options compiled in.
Sep 27 22:50:42 test xinetd[21286]: Started working: 1 available service
Sep 27 22:50:49 test xinetd[21286]: START: nrpe pid=21288 from=54.x.x.x
Sep 27 22:50:49 test xinetd[21286]: EXIT: nrpe status=0 pid=21288 duration=0(sec)

Check load on nagios host
# /usr/local/nagios/libexec/check_load
check_load: Could not parse arguments
Usage:
check_load [-r] -w WLOAD1,WLOAD5,WLOAD15 -c CLOAD1,CLOAD5,CLOAD15

There is no check_load on client, is that how it should be?

[lmiltchev]

You need to change the command definition on the client box to:

Code: Select all

command[check_load]=/usr/local/nagios/libexec/check_load $ARG1$

Restart the daemon, so that changes can take effect.

Next, test your check by running from the nagios server:

Code: Select all

./check_nrpe -H <client_ip> -c check_load -a 'w 15,10,5 -c 30,20,10'

Hope this helps.

[mishomor]

You need to change the command definition on the client box to:

Code: Select all

command[check_load]=/usr/local/nagios/libexec/check_load $ARG1$

Restart the daemon, so that changes can take effect.

Next, test your check by running from the nagios server:

Code: Select all

./check_nrpe -H <client_ip> -c check_load -a 'w 15,10,5 -c 30,20,10'

Hope this helps.

I just updated the line and restarted xinetd. I am still getting
NRPE: Unable to read output

Did you stumbled on bug or something? Maybe I should flip back to v.3.

[slansing]

There needs to be a dash before the w for warning threshold like so:

Code: Select all

'-w 15,10,5 -c 30,20,10'

[mishomor]

There needs to be a dash before the w for warning threshold like so:

Code: Select all

'-w 15,10,5 -c 30,20,10'

Nope, same error again.
$ ./check_nrpe -H test -c check_load -a '-w 15,10,5 -c 30,20,10'
NRPE: Unable to read output