[Solved] Nagios not sending alerts

[jbruyet]

Hey all, I have Nagios 4.0.6 running on CentOS 6.5. Everything is running smoothly so I decided it was time to implement alerting. Per some instructions I was following I uninstalled sendmail and installed postfix. These are my Nagios alerting configuration settings thus far:

nagios.cfg: notifications_enabled=1
Contact template: notifications_enabled=1
Define host has correct contact_groups
Define host has 15 minute notification_interval

I disabled the NIC on one of my servers for about 23 minutes but I never received an alert. I thought that maybe I messed up the postfix install but I ran the following test and it sent a text message to my phone:

echo "Wuzzup Guy" | mail -s "test email" MyPhone#@vtext.com

I looked at /usr/local/nagios/var/nagios.log and I couldn't find any errors.

So, I think the problem is in Nagios but I don't know where to look. Any ideas, suggestions or recommendations?

Thanks,

Joe B

[Box293]

Let's look at a few logs.

Firstly, sending a test alert can be quickly done this way:

• In the web interface click on a host
  Under host commands click "Send custom host notification"
  Add a comment and click Commit

So you can watch a couple of logs.

Firstly, there is this one:

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tail -f /var/log/messages

Send a test notification and see what appears here.

Also, does anything appear here:

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tail -f /usr/local/nagios/var/nagios.log

[jbruyet]

Well, now I have something to look into:

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Error: Could not open command file '/usr/local/nagios/var/rw/nagios.cmd' for update!

The permissions on the external command file and/or directory may be incorrect. Read the FAQs on how to setup proper permissions.

An error occurred while attempting to commit your command for processing.

Return from whence you came

Thanks,

Joe B

[jbruyet]

The permissions look good to me:

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[root@Nagios rw]# ls -l
total 0
prw-rw---- 1 nagios nagcmd 0 Jul 25 14:16 nagios.cmd
srw-rw---- 1 nagios nagcmd 0 Jul 25 14:16 nagios.qh
[root@Nagios rw]#

Thanks,

Joe B

[sreinhardt]

Let's check your groups, the cgi's will actually get run as the apache\httpd user, so permissions look good but there's more to it.

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grep -Ri 'nag' /etc/passwd
grep -Ri 'nag' /etc/group

[jbruyet]

Hi sreinhardt, here's what I'm seeing in /etc/passwd and /etc/group:

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[root@Nagios jobee]# grep -Ri 'nag' /etc/passwd
nagios:x:501:501::/home/nagios:/bin/bash
[root@Nagios jobee]# grep -Ri 'nag' /etc/group
nagios:x:501:
nagcmd:x:502:nagios
[root@Nagios jobee]#

Thanks,

Joe B

[Box293]

It looks like you need to add the apache user to the nagcmd group:

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usermod -a -G nagcmd apache

[jbruyet]

Thanks Box293, I'm no longer getting the error message. However, I have discovered that I need to make some tweaks in the commands.cfg file. Here's something from /var/log/messages:

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Jul 29 11:28:36 Nagios nagios: wproc:   host=srv-Dictum2; service=(none); contact=JobeePhone
Jul 29 11:28:36 Nagios nagios: wproc:   early_timeout=0; exited_ok=1; wait_status=32512; error_code=0;
Jul 29 11:28:36 Nagios nagios: wproc:   stderr line 01: /bin/sh: /usr/bin/mail: No such file or directory
Jul 29 11:28:36 Nagios nagios: wproc:   stderr line 02: /usr/bin/printf: write error: Broken pipe

I need to add a postfix command so Nagios knows how to send an email. I looked under /usr/bin for postfix and didn't quite find what I was looking for:

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lrwxrwxrwx. 1 root root         31 May  9 16:13 mailq.postfix -> ../../usr/sbin/sendmail.postfix
lrwxrwxrwx. 1 root root         31 May  9 16:13 newaliases.postfix -> ../../usr/sbin/sendmail.postfix
-rwxr-xr-x. 1 root root        262 Feb 20 02:07 rmail.postfix
[root@Nagios bin]# 

I did find a postfix under /usr/sbin but I'm not sure if I should use that command or something else. Suggestions?

[Box293]

Try:

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yum -y install mailx

And see if that works (without tweaking commands.cfg).

[jbruyet]

Bummer:

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updates/primary_db                                                                              | 4.2 MB     00:01
Setting up Install Process
Package mailx-12.4-7.el6.x86_64 already installed and latest version
Nothing to do
[root@Nagios jobee]#

If I were to tweak the commands.cfg file my only question is which postfix link/executable do I use?

Thanks,

Joe B