Question about service variables/macros

[ocolin]

Hello all, newbie here.

I am trying to use Nagios CORE to monitor OSPF and BGP in order to detect failures in redundant fiber and wireless links (which can't be detected by pinging). I have written some scripts to do this, however there is one issue I am running into. Some of the devices have different community strings or telnet (yes very old device) passwords. Right now I have to create a new service for each host to account for the varying passwords, etc. I doubt this is the correct way to do it.

Is it possible for me to store a community string with the host that can be passed to the service so that I can have just one service that can send a different community string for each host that uses the service?

Also, not sure if my wording is easy to understand, so if not, let me know and I can try to clarify. Thanks!

[jdalrymple]

I believe you're looking for custom object variables:

http://nagios.sourceforge.net/docs/3_0/ ... tvars.html

Is that right?

[ocolin]

Thank you jdalrymple. That is exactly what I am looking for.

However I am not sure how to get the host customer variable into a macro for the service. For example:

Code: Select all

define host {
        host_name             test.hostname.com
        alias                      Test Switch 1
        display_name         test.hostname.com
        address                  127.0.0.1
        parents                  Main_switch
        use                        router_template
        _COMMUNITY           mycommunitystring
        register                  1
}

Code: Select all

define service {
        host_name                       test.hostname.com
        service_description          Check OSPF on Vyatta
        display_name                   vyatta_ospf
        use                                  ospf_template
        check_command              check_vyatta_ospf!$_HOSTCOMMUNITY$
        register                        1
}

It's sending a literal string of '$_HOSTCOMMUNITY$' instead of the macro value. Clearly I am just formatting it incorrectly, but I am having a hard time telling how I could be formatting it in the service definition so that the service definition knows to use the macro from the host that is associated with the service definition. Any ideas on where I might be going wrong?

[jdalrymple]

That syntax looks proper to me ocolin, and works in my environment:

Code: Select all

define command{
        command_name    check_dummy
        command_line    $USER1$/check_dummy $ARG1$ $ARG2$
        }

Code: Select all

define host{
        use                     linux-server
        host_name               localhost
        alias                   localhost
        address                 127.0.0.1
        _COMMUNITY              bar
        }

Code: Select all

define service{
        service_description             foobar
        use                             local-service
        host_name                       localhost
        check_command                   check_dummy!0!$_HOSTCOMMUNITY$
        }

Maybe check for awkward whitespaces and such?

[ocolin]

Thank you again for your time. I am confused about one thing and it may be why I am having trouble. In your example, the macro in the service check_command is "$_HOSTFOO$", while the variable in the host is "_COMMUNITY".

I don't understand how it knows to replace $_HOSTFOO$ with the value of _COMMUNITY. I would have expected that the check_command would need to be "check_dummy!0!$_HOSTCOMMUNITY".

I mine instead of displaying 'bar' it displays '$' (I set the script to output the argument for the community string. I am going to set it back up and check for white spaces, but am just confused about how those variables and macros connect to each other in yours. Thanks!!

[jdalrymple]

Oh wow, I apologize for that. You were the victim of me editing code, then editing posts with edited code. I wanted to make sure that my check would work just the same using the exact syntax you used so I made some adjustments on the fly. I'll fix it to what it looks like in a working configuration. I guess to clarify - I'm now using the same exact syntax you're using and it's working for me.

What version of Nagios are you using?

[ocolin]

I re-entered it in the config files and now it's working. I must have had some kind of white-space something that I just could not see. Thank you again so much!