tool for adding required json attributes to add hosts to nagios

update_json_for_nagios.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'json'
require 'pp' if $DEBUG

class UpdateJsonForNagios
  
  KNIFE_CONFIG = "~/work/chef/.chef/knife.rb"

  def initialize(nodename)
    @nodename = nodename
  end
  
  def get_current_json
    @short_json = `/usr/bin/knife node show -c #{KNIFE_CONFIG} -F json #{@nodename}`
    @long_json  = `/usr/bin/knife node show -c #{KNIFE_CONFIG} -F json -l #{@nodename}`
  end
  
  def parse_current_json
    @parsed_json = JSON.parse(@short_json)
  end
  
  def add_required_attributes
    
    # adding "roles" attribute
    run_list = @parsed_json["run_list"]
    run_list = run_list.select {|r| r =~ /role/}
    run_list.map! {|r| r.sub(/role\[(.*)\]/,'\1')}
    @parsed_json["roles"] = %w{base} + run_list
    
    # adding "fqdn", "hostname", and "ipaddress" attributes
    parsed_long_json = JSON.parse(@long_json)
    @parsed_json["fqdn"] = parsed_long_json["automatic"]["fqdn"]
    @parsed_json["hostname"] = parsed_long_json["automatic"]["hostname"]
    @parsed_json["ipaddress"] = parsed_long_json["automatic"]["ipaddress"]

  end
  
  def return_final_json
    if $DEBUG
      pp @parsed_json
    else
      puts @parsed_json.to_json
    end
  end
  
  def run
    get_current_json
    parse_current_json
    add_required_attributes
    return_final_json
  end
end

if $0 == __FILE__
  UpdateJsonForNagios.new(ARGV.shift).run
end