sample.rb

port = 10051

s = Zabbix::Sender.new 'zabbix-server', port

pp s.send('host', 'key', 'value')
# => {"response"=>"success",
#     "info"=>"Processed 1 Failed 0 Total 1 Seconds spent 0.000042"}

pp s.to('host') {
  send 'key',  'value'
  send 'key1', 'value1'
  send 'key2', 'value2'
}
# => {"response"=>"success",
#     "info"=>"Processed 3 Failed 0 Total 3 Seconds spent 0.000029"}

Zabbix::Sender.send 'host', 'zabbix-server', port do
  send 'key', 'value'
end

zabbix-sender.rb

# -*- coding: utf-8 -*-
require 'socket'
require 'rubygems'
require 'json'
require 'pp'

module Zabbix
  class Sender
    def self.send(host, serv='localhost', port=10051, conf='/etc/zabbix/zabbix_agentd.conf', &blk)
      s = new serv, port, conf
      s.to host, &blk
    end

    def initialize(serv='localhost', port=10051, conf='/etc/zabbix/zabbix_agentd.conf')
      @serv, @port = serv, port
      load_conf conf
    end

    def to(host, &blk)
      raise ArgumentError, "need block" unless block_given?
      begin
        @keep = true
        @data = {}
        instance_eval &blk
        unless @data.empty?
          connect @data.map { |(key, value)|
            { :host => host.to_s, :key => key.to_s, :value => value.to_s }
          }
        end
      ensure
        @keep = @data = nil
      end
    end

    def send(*args)
      return register args if @keep
      host  = args.shift
      key   = args.shift
      value = args.shift
      connect :host => host.to_s, :key => key.to_s, :value => value.to_s
    end

    def register(args)
      key   = args.shift
      value = args.shift
      @data[key] = value
    end

    def connect(data)
      sock = nil
      begin
        sock = TCPSocket.new @serv, @port
        sock.write rawdata(data)
        parse sock.read
      ensure
        sock.close if sock
      end
    end

    def parse(response)
      JSON.parse response[13 .. -1]
    end

    def rawdata(data)
      data = [data] unless data.instance_of? Array
      baggage = {
        :request => 'sender data',
        :data    => data,
      }.to_json
      'ZBXD' + [1, u64le(baggage.bytesize)].flatten.pack("C*") + baggage
    end

    def u64le(integer)
      ary = []
      8.times do |n|
        ary << ((integer >> (n * 8)) & 0xFF)
      end
      ary
    end

    def load_conf(path)
      return unless FileTest.exist? path
      File.open(path, 'rb') do |f|
        f.readlines.each do |line|
          line.gsub!(/#.*$/, '')
          if line =~ /(Server(?:Port)?)\s*=\s*([0-9a-zA-Z\-\_\.]+)\s*/
            key, value = $1, $2
            @serv = value if key == 'Server'
            @port = value if key == 'ServerPort'
          end
        end
      end
    end
  end
end