check_nwc_health command for Icinga 2

nwc_health.conf

object CheckCommand "nwc_health" {
  import "plugin-check-command"

  command = [ "/etc/icinga2/plugins/check_nwc_health" ]

  arguments = {
    "-H" = "$nwc_address$"
    "--community" = "$snmp_community$"
    "--protocol" = "$snmp_protocol$"
    "--mode" = "$nwc_mode$"
    "--warning" = "$nwc_warning$"
    "--critical" = "$nwc_critical$"
    "--name" = "$nwc_name$"
  }

  vars.snmp_community = "public"
  vars.nwc_address = "$address$"
  vars.nwc_timeout = 15
  vars.snmp_protocol = "2c"
}

nwc_health_demo.conf

object Host "core-switch" {
  import "generic-host"
  address = "127.0.0.1"

  vars.snmp_community = "mysecretpublic"

  vars.interfaces["GigabitEthernet0/1"] = {
    description = "Management"
  }
  vars.interfaces["GigabitEthernet0/2"] = {
    description = "Uplink 1"
  }
  vars.interfaces["GigabitEthernet0/3"] = {
    description = "Uplink 2"
  }
  vars.interfaces["Port-Channel1"] = {
    description = "Main Uplink"
  }
}

apply Service "if-status" for (if_name => config in host.vars.interfaces) {
  import "generic-service"

  name = "interface " + if_name + " status"
  notes = config.description

  command = "nwc_health"
  
  vars.nwc_mode = "interface-status"
  vars.nwc_name = if_name
}