Nagios Support Forum • Alert if a process IS running, rather than if it isn't

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Alert if a process IS running, rather than if it isn't

Posted: Thu Aug 13, 2015 9:27 am

by neworderfac33

Good afternoon,

We are trying to adopt a policy where editing tools such as Notepad or Notepad++ are only installed on and run from a local PC to edit files on remote servers, rather than having them installed on each server.

So, I want my alerts to show when a process IS running, rather than when it isn't.

Here's an example from my Windows.cfg - how do I adapt it to send the alerts when Notepad++ IS running instead?

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define service{
        use                     generic-service
        #host_name              MN2SVWBDT001SD0, MN2SVWBDT001SU0
        hostgroup_name          windows-servers
        service_description     Application - Notepad ++
        check_command           check_nt!PROCSTATE! -d SHOWALL -l Notepad++.exe
        }

Thanks in advance

Pete

Re: Alert if a process IS running, rather than if it isn't

Posted: Thu Aug 13, 2015 9:50 am

by tmcdonald

Yo

https://assets.nagios.com/downloads/nag ... ios-XI.pdf

Works for Core too, you just have to edit the config files instead of using the web configuration interface.

Re: Alert if a process IS running, rather than if it isn't

Posted: Thu Aug 13, 2015 10:55 am

by neworderfac33

Good afternoon - thank you for taking the time to reply!

Code: Select all

define service{
        use                     generic-service
        #host_name              SERVER1, SERVER2
        hostgroup_name          windows-servers
        service_description     Application - Notepad ++
        check_command           check_nt!negate!PROCSTATE! -d SHOWALL -l Notepad++.exe
        }

returned: "check_nt: Could not parse arguments" in the browser.

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define service{
       use                      generic-service
       #host_name               SERVER1, SERVER2
       hostgroup_name           windows-servers
       service_description      Application - Notepad
       check_command            negate!check_nt!PROCSTATE!-d SHOWALL -l Notepad.exe

threw out an error during verify.

Code: Select all

define service{
        use                     generic-service
        #host_name              SERVER1, SERVER2
        hostgroup_name          windows-servers
        service_description     Application - Notepad ++
        check_command           check_nt!PROCSTATE!negate! -d SHOWALL -l Notepad++.exe
        }

returned "No service/process specified" in the browser.

How do I correctly include the negate parameter, please?

Actually, how do I even know whether the negate plugin is installed at all? Is it one that comes with the Nagios Core installation, or does it have to be installed separately?

I'm using Nagios Core within RedHat Enterprise 6.6

Thanks

Pete

Re: Alert if a process IS running, rather than if it isn't

Posted: Thu Aug 13, 2015 12:12 pm

by jolson

The negate parameter must be run in front of the command that you're attempting to run. e.g.

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cd /usr/local/nagios/libexec

Without Negate:

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./check_nrpe -H 127.0.0.1

NRPE v2.15

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echo $?

0

With Negate:

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./negate ./check_nrpe -H 127.0.0.1

NRPE v2.15

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echo $?

2

Your check command_definition should look like this:

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        check_command           negate!check_nt!PROCSTATE! -d SHOWALL -l Notepad++.exe

What happens if you run the following from the command line?

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/usr/local/nagios/libexec/negate /usr/local/nagios/libexec/check_nt -H x.x.x.x -p 12489 -v PROCSTATE -d SHOWALL -l Notepad++.exe

Re: Alert if a process IS running, rather than if it isn't

Posted: Fri Aug 14, 2015 3:25 am

by neworderfac33

Good morning,

In answer to your final question, running from the command line returns:

Notepad++.exe: not running

When attempting to verify my windows.cfg, which includes:

Code: Select all

define service{
        use                     generic-service
        #host_name              MYFIRSTSERVER, MYSECONDSERVER
        hostgroup_name          windows-servers
        service_description     Application - Notepad ++
        check_command           negate!check_nt!PROCSTATE! -d SHOWALL -l notepad++.exe
        }

I get:

Error: Service check command 'negate!check_nt!PROCSTATE! -d SHOWALL -l Notepad++.exe' specified in service 'Application - Notepad ++' for host 'MYSERVER1' not defined anywhere!
Error: Service check command 'negate!check_nt!PROCSTATE! -d SHOWALL -l Notepad++.exe' specified in service 'Application - Notepad ++' for host 'MYSERVER2' not defined anywhere!

Not sure if it was worth my while, but I also tried prefixing the negate command with the full path thus:

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check_command          /usr/local/nagios/libexec/negate!check_nt!PROCSTATE! -d SHOWALL -l Notepad++.exe

but this didn't work either.
I've gone into the /usr/local/nagios/libexec folder and confirmed that negate is there:

-rwxr-xr-x 1 nagios nagios 131089 Jul 23 12:16 negate

Thanks

Pete

Re: Alert if a process IS running, rather than if it isn't

Posted: Fri Aug 14, 2015 10:27 am

by neworderfac33

...oh, and by the way, if anyone takes the trouble to reply to this and they don't get a reply, it's because I'll be on leave next week, with no Internet access.

At least, that's what I'll be telling my 12 year old!

Pete

Re: Alert if a process IS running, rather than if it isn't

Posted: Fri Aug 14, 2015 12:08 pm

by hsmith

Pete, a few things.

I am guessing that you have not made a command for negate. I'll walk you through how I did this:

Open up commands.cfg

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vi /usr/local/nagios/etc/commands.cfg

Add a command for negate, this is mine ( you can do it prettier and nicer, this is just a fast one I wrote up trying to catch you before you took off )

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define command {
       command_name                             negate2
       command_line                             $USER1$/negate $USER1$/$ARG1$
}

I chose to do this with one argument for simplicity's sake.

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define service {
        host_name                       my.pc.name
        service_description             peterooney notepad++ negate test
        use                             generic-service
        check_command                   negate2!/check_nt -H x.x.x.x -p 12489 -s mypassword -v PROCSTATE -d SHOWALL -l "notepad++.exe"!!!!!!!
        }

That way, you can just use negate(negate 2 in my case) and whatever you want to call after it. I could have done this a little bit nicer and separated it out into more arguments, but this gets the job done.

Try this out and let me know if it works for you!

Edit: enjoy your vacation-thing!

Re: Alert if a process IS running, rather than if it isn't

Posted: Mon Aug 24, 2015 3:28 am

by neworderfac33

Good morning, and thanks for your reply!

My commands.cfg is in /usr/local/nagios/etc/objects, which foxed me for a while!

Anyhow, I added this:

Code: Select all

define command {
        command_name    negatepr
        command_line    $USER1$/negate $USER1$/$ARG1$
}

and I amended my windows.cfg as follows:

Code: Select all

define service{
        use                           generic-service
        #host_name              MYFIRSTSERVER, MYSECONDSERVER
        hostgroup_name       windows-servers
        service_description   Application - Notepad++ Version 2
        check_command       negatepr!/check_nt -v PROCSTATE -d SHOWALL -l "Notepad++.exe"!!!!!!!
        }

This throws out: check_nt: You must provide a server address or host name in the browser.

Unfortunately, I don't want to have to specify the server IDs in the service, as in your suggestion, as I prefer to define them all as windows-servers and refer to that instead,

Could you also explain the significance of the exclamation marks at the end of the command, please? If I'm omitting the port and password parameters, do I only need 5 instead of seven?

Thanks

Pete

Re: Alert if a process IS running, rather than if it isn't

Posted: Mon Aug 24, 2015 10:34 am

by jdalrymple

In a check_command directive of a service definition the ! character separates arguments.

peterooney wrote:

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        command_line    $USER1$/negate $USER1$/$ARG1$

...

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        check_command       negatepr!/check_nt -v PROCSTATE -d SHOWALL -l "Notepad++.exe"!!!!!!!

Get rid of your leading / - it's redundant

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        check_command       negatepr!check_nt -v PROCSTATE -d SHOWALL -l "Notepad++.exe"!!!!!!!

peterooney wrote:Unfortunately, I don't want to have to specify the server IDs in the service, as in your suggestion, as I prefer to define them all as windows-servers and refer to that instead,

That's why we have the $HOSTADDRESS$ macro. Just apply your service to whatever host you like and Nagios takes care of the rest.

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        check_command       negatepr!check_nt -H $HOSTADDRESS$ -v PROCSTATE -d SHOWALL -l "Notepad++.exe"!!!!!!!

Also - I've found check_nt to have mixed reliability when not specifying the port:

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        check_command       negatepr!check_nt -H $HOSTADDRESS$ -p 12489 -v PROCSTATE -d SHOWALL -l "Notepad++.exe"!!!!!!!

Have a blast.

Re: Alert if a process IS running, rather than if it isn't

Posted: Mon Aug 24, 2015 10:49 am

by neworderfac33

Thanks for your reply!

I must admit, I'm fast losing faith in my ability to ever get this sorted - I've spent the equivalent of four working days (five including today) trying to get one negate command working and I really am coming to the end of my rope.

My post seems to have become corrupted somehow - my final question was what was the significance of all the trailing exclamation marks on the check_command line - Do they need to be there and do I need seven of them - oh, and does notepad++.exe need to be within double quotes? I have followed the previous poster's instructions to the letter, perhaps without totally understanding them.

On the assumption that I have to create negatepr (or equivalent) in commands.cfg, and that there's no way to achieve what I want without doing so, Is there any reason why the following shouldn't work?

COMMANDS.CFG

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define command {
        command_name    negatepr
        command_line    $USER1$/negate $USER1$/$ARG1$
}

WINDOWS.CFG

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define host{
        use             windows-server
        host_name       FIRSTSERVER
        alias           Dev-Jenkins
        address         88.88.88.88
        hostgroups      windows-servers
}

define host{
        use             windows-server
        host_name       SECONDSERVER
        alias           UAT-Jenkins
        address         99.99.99.99
        hostgroups      windows-servers
        }

define hostgroup{
        hostgroup_name  windows-servers
        alias           Jenkins Test Servers
}

define service{
        use                     generic-service
        #host_name               FIRSTSERVER, SECONDSERVER
        hostgroup_name         windows-servers
        service_description     Application - Notepad++ Version 2
        check_command           negatepr!check_nt -v PROCSTATE -d SHOWALL -l "Notepad++.exe"
        }

At the moment, the browser is returning:

Code: Select all

check_nt: You must provide a server address or host name

Thanks for your help.
Pete