235 lines
6.9 KiB
Plaintext
235 lines
6.9 KiB
Plaintext
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NRPE README
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** UPDATED DOCUMENTATION!
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For installation instructions and information on the design overview
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of the NRPE addon, please read the PDF documentation that is found in
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this directory: NRPE.pdf
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Purpose
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-------
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The purpose of this addon is to allow you to execute Nagios
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plugins on a remote host in as transparent a manner as possible.
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Contents
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--------
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There are two pieces to this addon:
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1) NRPE - This program runs as a background process on the
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remote host and processes command execution requests
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from the check_nrpe plugin on the Nagios host.
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Upon receiving a plugin request from an authorized
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host, it will execute the command line associated
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with the command name it received and send the
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program output and return code back to the
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check_nrpe plugin
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2) check_nrpe - This is a plugin that is run on the Nagios host
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and is used to contact the NRPE process on remote
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hosts. The plugin requests that a plugin be
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executed on the remote host and wait for the NRPE
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process to execute the plugin and return the result.
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The plugin then uses the output and return code
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from the plugin execution on the remote host for
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its own output and return code.
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Compiling
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---------
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The code is very basic and may not work on your particular
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system without some tweaking. I just haven't put a lot of effort
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into this addond. Most Linux users should be able to compile
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NRPE and the check_nrpe plugin with the following commands...
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./configure
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make all
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The binaries will be located in the src/ directory after you
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run 'make all' and will have to be installed manually somewhere
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on your system.
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NOTE: Since the check_nrpe plugin and nrpe daemon run on different
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machines (the plugin runs on the Nagios host and the daemon
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runs on the remote host), you will have to compile the nrpe
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daemon on the target machine.
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Installing
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----------
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The check_nrpe plugin should be placed on the Nagios host along
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with your other plugins. In most cases, this will be in the
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/usr/local/nagios/libexec directory.
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The nrpe program and the configuration file (nrpe.cfg) should
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be placed somewhere on the remote host. Note that you will also
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have to install some plugins on the remote host if you want to
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make much use of this addon.
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Configuring
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-----------
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Sample config files for the NRPE daemon are located in the
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sample-config/ subdirectory.
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Running Under INETD or XINETD
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-----------------------------
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If you plan on running nrpe under inetd or xinetd and making use
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of TCP wrappers, you need to do the following things:
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1) Add a line to your /etc/services file as follows (modify the port
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number as you see fit)
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nrpe 5666/tcp # NRPE
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2) Add entries for the NRPE daemon to either your inetd or xinetd
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configuration files. Which one your use will depend on which
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superserver is installed on your system. Both methods are described
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below. NOTE: If you run nrpe under inetd or xinetd, the server_port
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and allowed_hosts variables in the nrpe configuration file are
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ignored.
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***** INETD *****
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If your system uses the inetd superserver WITH tcpwrappers, add an
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entry to /etc/inetd.conf as follows:
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nrpe stream tcp nowait <user> /usr/sbin/tcpd <nrpebin> -c <nrpecfg> --inetd
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If your system uses the inetd superserver WITHOUT tcpwrappers, add an
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entry to /etc/inetd.conf as follows:
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nrpe stream tcp nowait <user> <nrpebin> -c <nrpecfg> --inetd
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- Replace <user> with the name of the user that the nrpe server should run as.
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Example: nagios
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- Replace <nrpebin> with the path to the nrpe binary on your system.
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Example: /usr/local/nagios/nrpe
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- Replace <nrpecfg> with the path to the nrpe config file on your system.
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Example: /usr/local/nagios/nrpe.cfg
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***** XINETD *****
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If your system uses xinetd instead of inetd, you'll probably
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want to create a file called 'nrpe' in your /etc/xinetd.d
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directory that contains the following entries:
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# default: on
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# description: NRPE
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service nrpe
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{
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flags = REUSE
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socket_type = stream
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wait = no
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user = <user>
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server = <nrpebin>
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server_args = -c <nrpecfg> --inetd
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log_on_failure += USERID
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disable = no
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only_from = <ipaddress1> <ipaddress2> ...
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}
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- Replace <user> with the name of the user that the nrpe server should run as.
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- Replace <nrpebin> with the path to the nrpe binary on your system.
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- Replace <nrpecfg> with the path to the nrpe config file on your system.
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- Replace the <ipaddress> fields with the IP addresses of hosts which
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are allowed to connect to the NRPE daemon. This only works if xinetd was
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compiled with support for tcpwrappers.
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3) Restart inetd or xinetd will the following command (pick the
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on that is appropriate for your system:
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/etc/rc.d/init.d/inet restart
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/etc/rc.d/init.d/xinetd restart
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OpenBSD users can use the following command to restart inetd:
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kill -HUP `cat /var/run/inet.pid`
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4) Add entries to your /etc/hosts.allow and /etc/hosts.deny
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file to enable TCP wrapper protection for the nrpe service.
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This is optional, although highly recommended.
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Configuring Things On The Nagios Host
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---------------------------------------
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Examples for configuring the nrpe daemon are found in the sample
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nrpe.cfg file included in this distribution. That config file
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resides on the remote host(s) along with the nrpe daemon. The
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check_nrpe plugin gets installed on the Nagios host. In order
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to use the check_nrpe plugin from within Nagios, you'll have
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to define a few things in the host config file. An example
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command definition for the check_nrpe plugin would look like this:
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define command{
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command_name check_nrpe
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command_line /usr/local/nagios/libexec/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
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}
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In any service definitions that use the nrpe plugin/daemon to
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get their results, you would set the service check command portion
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of the definition to something like this (sample service definition
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is simplified for this example):
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define service{
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host_name someremotehost
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service_description someremoteservice
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check_command check_nrpe!yourcommand
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... etc ...
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}
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where "yourcommand" is a name of a command that you define in
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your nrpe.cfg file on the remote host (see the docs in the
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sample nrpe.cfg file for more information).
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Questions?
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If you have questions about this addon, or problems getting things
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working, first try searching the nagios-users mailing list archives.
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Details on searching the list archives can be found at
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http://www.nagios.org
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If all else fails, you can email me and I'll try and respond as
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soon as I get a chance.
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-- Ethan Galstad (nagios@nagios.org)
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