Several Servers hidden behind single IP

[tkircht]

We have several customers that hide more than one (Windows/NSClient++) server behind one single IP-address. What I usually do in these cases is forward increasing port numbers to those hosts (12489-> HostA, 12490->HostB, 12491->HostC, etc.). On the Nagios side I need to create a service definition for every combination of portnumber and service ( one for CPULOAD at 12489, CPULOAD at 12490, etc.) which tends to fill the service-definitions-file with a bunch of definition entries.

Can anybody stir me towards a better (i.e. more readable and manageable) setup for this problem? I'd love a way to pass the port number to the host definition and use a generic definition for each service. I feel like I could add the port number to the host address (12.34.56.78:1290) but am at a loss on how to parse this in the command definition.

Any ideas for me there?

Thanks for any hints!

Thomas

[tkircht]

I guess I solved it myself - was rather straightforward even. Just in case anyone needs this... Feel free to comment if you see something you don't like...

Parser script:

Code: Select all

  1 #!/bin/bash
  2 # check_parse_nt
  3 # parses socket and executes check_nt
  4 # Thomas Kirchtag 2011
  5
  6 #
  7 FULLADDRESS="${1}"
  8 shift
  9
 10 IPADDRESS="${FULLADDRESS%:*}"
 11 PORTNUMBER="${FULLADDRESS#*:}"
 12 CHECK_NT="/usr/lib/nagios/plugins/check_nt"
 13 $CHECK_NT -H "${IPADDRESS}" -p "${PORTNUMBER}" "$@"

command definitions:

Code: Select all

define command {
  command_name  check-nt-variable
  command_line $USER1$/check_parse_nt $HOSTADDRESS$ -v $ARG1$ $ARG2$
}

define command {
  command_name  check-host-alive-nt-variable
  command_line  $USER1$/check_parse_nt  $HOSTADDRESS$ -v CLIENTVERSION $ARG1$ $ARG2$
}

Host template:

Code: Select all

# Generic NSClient-Host
define host{
        use                             generic-host;
        name                            nsclient-host-variable    ; The name of this host template
        check_command                   check-host-alive-nt-variable!CLIENTVERSION! -p12490 -s Password
        hostgroups                      windows-servers,NSClient-Servers-variable
        register                        0       ; 
        }

Sample host definition:

Code: Select all

define host {
  use nsclient-host-variable;
  host_name 0000-002-IP-W2K8R2-03;
  address  123.45.67.17:12490;
  check_command check-host-alive-nt-variable
}

Service template:

Code: Select all

define service {
    use                             generic-service
    name                            nsclient-service
    notification_interval           0 ; set > 0 if you want to be renotified
    max_check_attempts              3
    register                        0
 }

Sample service definition:

Code: Select all

define service {
        use                             nsclient-service
        hostgroup_name                  NSClient-Firewall-2K8-variable
        service_description             Firewall
        check_command                   check-nt-variable!SERVICESTATE!-l 'MpsSvc'  -s Password 
}

[JenyZ]

I actually found this very helpful....kinda a newbie with php, talk about mind boggling, but am enjoying all the techie language!

[tkircht]

Well, seeing that somebody (Hi Jeny!) is actually reading this I have to admit that I threw that solution into the garbage bin already. The clean way to solve this problem of course uses user-defined macros and good host templates. I now have all my host specific information like port numbers, urls etc in my host definitions and address these macros from within my command.cfg. Just a small sample - tell me if you need more:

Code: Select all

 define host {
   use nsclient-host-variable;
   host_name 0000-002-IP-W2K8R2-03;
   address  12.34.56.17;
   _NSCP_PORT  12490;
   _NSCP_PW  topsecret;
   check_command check-host-alive-nt-variable
   hostgroups +NSClient-AD-2K8,NSClient-Firewall-2K8
 }

Code: Select all

 define command {
   command_name  check-nt-variable
   command_line $USER1$/check_nt -H $HOSTADDRESS$ -p $_HOSTNSCP_PORT$ -s $_HOSTNSCP_PW$ -v $ARG1$ $ARG2$
 }