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2014-11-20T21:43:21Z

Die Seite wurde neu angelegt: „== Nagios == === Aktivieren von External Commands === Nagios 3 is not configured to look for external commands in the default configuration as a security featur…“

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== Nagios ==
=== Aktivieren von External Commands ===
Nagios 3 is not configured to look for external commands in the
default configuration as a security feature. To enable external
commands, you need to allow the web server write access to the
nagios command pipe. the simplest way of doing this is to
set check_external_commands=1 in your nagios configuration,
and then change the permissions in a way which will be maintained
across package upgrades (otherwise dpkg will overwrite your
permission changes). The following is the recommended approach:

- activate external command checks in the nagios configuration. this
can be done by setting check_external_commands=1 in the file
/etc/nagios3/nagios.cfg.

sed -i "s/check_external_commands=0/check_external_commands=1/" /etc/nagios3/nagios.cfg

- perform the following commands to change directory permissions and
to make the changes permanent:

/etc/init.d/nagios3 stop
dpkg-statoverride --update --add nagios www-data 2710 /var/lib/nagios3/rw
dpkg-statoverride --update --add nagios nagios 751 /var/lib/nagios3
/etc/init.d/nagios3 start

This is done by intention and will not fixed. See also #538828 for more informations.

=== Mails Benachichtigungen Limitieren ===
If you want to receive only 1 mail, it's easy. Set the
notification_interval to 0. But if you want 2, I guess you might achieve
this using escalation and setting notification_interval to 0.
Defining escalation with first_notification 2, and last_notification 2,
it should work.

I must admit I haven't tried it though.

== Nagios Grapher ==
== Nagios Troubleshoot ==
=== External Command Error===

ERROR:

Error: Could not stat() command file '/var/lib/nagios3/rw/nagios.cmd'!

Lösung:

chmod g+x /var/lib/nagios3/rw

vi /etc/nagios3/nagios.cfg

check_external_commands=1

vi /etc/group

nagios:x:118:www-data

Quell:

I have run into this problem the last three times I have set up Nagios, and every time I fix it, I forget to document the process. So here's the documentation. The first few points are covered in the official Nagios documentation that comes with your package. The later points are not, and have more to do with OS configuration.

My configuration:

Debian 5.3
Nagios 3

Configure nagios.cfg

Make sure you have something like this in /etc/nagios3/nagios.cfg:

# EXTERNAL COMMAND OPTION
# Values: 0 = disable commands, 1 = enable commands

check_external_commands=1

# EXTERNAL COMMAND CHECK INTERVAL
# NOTE: Setting this value to -1 causes Nagios to check the external
# command file as often as possible.

command_check_interval=15s
#command_check_interval=-1

# EXTERNAL COMMAND FILE
command_file=/var/lib/nagios3/rw/nagios.cmd

You will need to restart Nagios for these settings to be loaded.
Configure cgi.cfg

Next, edit the /etc/nagios3/cgi.cfg file and check the following:

# SYSTEM/PROCESS COMMAND ACCESS
authorized_for_system_commands=nagiosadmin

# ... Other stuff cut

# GLOBAL HOST/SERVICE COMMAND ACCESS
authorized_for_all_service_commands=nagiosadmin
authorized_for_all_host_commands=nagiosadmin

This enables the user nagiosadmin to submit commands. You can check out the in-file documentation for setting up multiple users.

Restart Apache2 after you have done this.
Add www-data to the Nagios Group

Next, make sure that the user www-data is in the group nagios. You can check on this in /etc/group.
Set the Permissions

This last item is the tricky one. You need to set the correct permissions for the command pipe file (this is the file set in nagios.cfg). Nagios uses this pipe to pass data from the CGI to the backend daemon.

This file is located in /var/lib/nagios3/rw/nagios.cmd.

By default, it should have the following permissions:

# ls -l /var/lib/nagios3/rw/nagios.cmd
prw-rw---- 1 nagios nagios 0 2010-01-13 10:17 /var/lib/nagios3/rw/nagios.cmd

Notice that the group ownership is nagios. That's why you added www-data to the nagios group above.

But even with these permissions, you may (will?) still get an error. The reason for this is that the parent directory, rw, does not allow any user but nagios to access its contents:

# ls -lh /var/lib/nagios3
total 92K
-rw-r--r-- 1 nagios nagios 33K 2010-01-04 17:06 objects.precache
-rw------- 1 nagios www-data 48K 2010-01-13 10:17 retention.dat
drwx------ 2 nagios www-data 4.0K 2010-01-13 10:17 rw
drwxr-x--- 3 nagios nagios 4.0K 2010-01-04 16:00 spool

All you need to do to fix this is add the execute bit (x) to the rw directory:

# chmod g+x /var/lib/nagios3/rw

Now any member of the nagios group (including www-data) should be able to access the contents of the rw directory.

At this point, you should be able to execute Nagios Service Commands through the web interface. (If not, try doing a stop/start of nagios and try again).

===Command not defined ===
'''Problem:'''
You monitor a remote server with Nagios or Icinga and see the following errors in your Nagios/Icinga web interface:

NRPE: Command 'check_all_disks' not defined
NRPE: Command 'check_mysql_cmdlinecred' not defined
NRPE: Command 'check_procs' not defined

'''Lösung:'''

vi /etc/nagios/nrpe.cfg

... and add command definitions for each service check that gives and error (e.g. check_procs):

[...]
command[check_procs]=/usr/lib/nagios/plugins/check_procs -w 250 -c 400
command[check_all_disks]=/usr/lib/nagios/plugins/check_disk -w '20%' -c '10%' -e
command[check_mysql_cmdlinecred]=/usr/lib/nagios/plugins/check_mysql -H localhost -u 'nagios' -p 'howtoforge'
[...]

Save the file and restart the NRPE server:

/etc/init.d/nagios-nrpe-server restart

== Links ==
* http://nagios.manubulon.com/traduction/docs14en/templatetricks.html
* http://www.nagios-wiki.de/nagios/howtos/nagiosgrapher
* http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=571801
* http://osdir.com/ml/network.nagios.plugins/2008-05/msg00070.html

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Thomas: Die Seite wurde neu angelegt: „== Nagios == === Aktivieren von External Commands === Nagios 3 is not configured to look for external commands in the default configuration as a security featur…“