include_dir function does not work RHEL7

[nigemar]

Hi, I am trying to configure nrpe to use the configuration files that we drop under include_dir configuration in the nrpe.cfg file.

I have found that on our RHEL7 boxes when we set this configuration as follows:

include_dir=/etc/nagios/nrpe.d

and add the following file:

nrpe_nifi_cluster.cfg

# puppet managed
command[check_nifi_cluster_query]=/usr/local/bin/nifi-cluster-query.sh

When the nagios runs the check, we get an error saying the command 'check_nifi_cluster_query' not defined:

Running the code from nagios

/usr/lib64/nagios/plugins/check_nrpe -H nifi-03.local-p 5666 -t 30 -c check_nifi_cluster_q                                                            uery
NRPE: Command 'check_nifi_cluster_query' not defined

The nrpe versions information is as follows:

Name        : nrpe
Version     : 3.2.1
Release     : 8.el7
Architecture: x86_64
Install Date: Thu 08 Nov 2018 11:03:36 AEST
Group       : Applications/System
Size        : 364786
License     : GPLv2
Signature   : RSA/SHA256, Wed 17 Oct 2018 02:05:05 AEST, Key ID 6a2faea2352c64e5
Source RPM  : nrpe-3.2.1-8.el7.src.rpm
Build Date  : Wed 17 Oct 2018 01:52:50 AEST
Build Host  : buildvm-06.phx2.fedoraproject.org
Relocations : (not relocatable)
Packager    : Fedora Project
Vendor      : Fedora Project
URL         : http://www.nagios.org
Bug URL     : https://bugz.fedoraproject.org/nrpe
Summary     : Host/service/network monitoring agent for Nagios
Description :
Nrpe is a system daemon that will execute various Nagios plugins
locally on behalf of a remote (monitoring) host that uses the
check_nrpe plugin.  Various plugins that can be executed by the
daemon are available at:
http://sourceforge.net/projects/nagiosplug

While we have the same configuration on RHEL 6 server:

/etc/nagios/nrpe.cfg

# Process the include last of all (this will override any check defined above)
include_dir=/etc/nagios/nrpe.d

File listing on RHEL 6

-rw-r--r--. 1 root root  493 May 15 18:15 vmware.cfg
-rw-r--r--. 1 root root  151 Jun  2 12:25 atm.cfg

atm.cfg

command[check_atm_logs]=/etc/nagios/plugins/check_atm_conns.py -l $ARG1$ -s $ARG2$ -n $ARG3$ -w $ARG4$ -c $ARG5$

Result:

OK: (lines: 2000) last connection from IP [xxx.xxx.xxx.xxxx] in subnet [public] at [2019-09-03 10:18:27]

Client server nrpe

Name        : nrpe                         Relocations: (not relocatable)
Version     : 3.2.1                             Vendor: Fedora Project
Release     : 6.el6                         Build Date: Wed 25 Jul 2018 08:59:08 AEST
Install Date: Wed 22 May 2019 16:05:29 AEST      Build Host: buildvm-32.phx2.fedoraproject.org
Group       : Applications/System           Source RPM: nrpe-3.2.1-6.el6.src.rpm
Size        : 366234                           License: GPLv2
Signature   : RSA/8, Wed 25 Jul 2018 09:01:50 AEST, Key ID 3b49df2a0608b895
Packager    : Fedora Project
URL         : http://www.nagios.org
Summary     : Host/service/network monitoring agent for Nagios
Description :
Nrpe is a system daemon that will execute various Nagios plugins
locally on behalf of a remote (monitoring) host that uses the
check_nrpe plugin.  Various plugins that can be executed by the
daemon are available at:
http://sourceforge.net/projects/nagiosplug

[sawolf]

Can you show file permissions for the directory? ls -l -d /etc/nagios/nrpe.d

Are you able to find any messages in your log_file (defaults to /usr/local/nagios/var/nrpe.log)?

[nigemar]

Sure,

Here is the permission set for the host that is failing to find the checks:

total 4
drwxr-xr-x. 2 root root 35 Sep  2 12:45 ./
drwxrwxr-x. 5 root root 68 Sep  2 15:04 ../
-rw-r--r--. 1 root root 89 Sep  2 12:19 nrpe_nifi_cluster.cfg

/etc/nagios/nrpe.d# ls -ld .
drwxr-xr-x. 2 root root 35 Sep  2 12:45 ./

Here is the SELinux contexts applied to the nrpe.cfg and the nrpe_nifi_cluster.cfg

/etc/nagios# ls -lZ /etc/nagios/nrpe.cfg  /etc/nagios/nrpe.d/nrpe_nifi_cluster.cfg
-rw-r--r--. root root system_u:object_r:nrpe_etc_t:s0  /etc/nagios/nrpe.cfg
-rw-r--r--. root root system_u:object_r:nrpe_etc_t:s0  /etc/nagios/nrpe.d/nrpe_nifi_cluster.cfg

Here is the boolean for nagios sudo

/etc/nagios# getsebool -a |grep -i nagios_run_sudo
nagios_run_sudo --> on

Looking at /var/log/messages, this an SELinux issue:

2019-09-04T07:49:29.142982+10:00 enk-nifi-03 nrpe[12711]: Could not open config directory '/etc/nagios/nrpe.d' for reading.
2019-09-04T07:49:29.143497+10:00 enk-nifi-03 nrpe[12711]: Continuing with errors...
2019-09-04T07:49:29.147873+10:00 enk-nifi-03 nrpe[12711]: Starting up daemon
2019-09-04T07:49:29.150269+10:00 enk-nifi-03 nrpe[12711]: Server listening on 0.0.0.0 port 5666.
2019-09-04T07:49:29.150983+10:00 enk-nifi-03 nrpe[12711]: Warning: Daemon is configured to accept command arguments from clients!
2019-09-04T07:49:29.151522+10:00 enk-nifi-03 nrpe[12711]: Listening for connections on port 5666
2019-09-04T07:49:29.152076+10:00 enk-nifi-03 nrpe[12711]: Allowing connections from: xxx.xsx.xsx.xxx, xxx.xsx.xsx.xxx, xxx.xsx.xsx.xxx

Do you know what context needs to be set for this directory and contents?

[nigemar]

I have tried setting the context to use both nrpe_etc_t and nagios_etc_t and both still give the same warning about not being able to read Could not open config directory '/etc/nagios/nrpe.d' for reading.

Do you know what the correct context should be?

[nigemar]

Turns out setting the module context to be: etc_t allows the SELinux to read this correctly.

I am guessing the nrpe_etc_t or nagios_etc_t is broken in terms of system access. Do I need to submit this to red hat or this a policy you have developed?

[sawolf]

Okay, that makes more sense. We don't maintain anything with regard to SELinux. If I remember correctly, this is part of a package distributed by Fedora/EPEL, so I'm not sure if you'd submit to Red Hat or somewhere else.

[nigemar]

Than, I will raise a ticket with EPEL and then link it back to here and vice versa.

Thanks.

[nigemar]

EPEL bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1749156

[mhjacks]

We're working on updating the SELinux policy relative to nagios and NRPE in epel7; this issue should be fixed soon.

[jbeaujour]

Hello, It seems there is the same behaviour on RH8 and 4.0.2-2 and SELinux enabled On RH7 4.0.3-6, it works fine but without SELinux