gistfile1.txt

#!/usr/bin/env ruby

require 'net/http'

require 'rubygems'
require 'json'
require 'pp'

### Server Details
@server="198.61.1.1"
@api="/zabbix/api_jsonrpc.php"

### Login Details
@user="user"
@pass="pass"

@json_auth_data ={
  "jsonrpc" => "2.0",
  "method" => "user.login",
  "params" => {"user" => @user,"password" => @pass}, 
  "id" => "1 "
}.to_json

def authenticate
  req = Net::HTTP::Post.new(@api, initheader = {'Content-Type' =>'application/json'})
    req.body = @json_auth_data  
    response = Net::HTTP.new(@server).start {|http| http.request(req) }
    puts "Response #{response.code} #{response.message}:
    #{response.body}"
end

result = authenticate

auth = JSON.parse(result)

auth_token = auth['result']

pp auth_token

##### authenticate response
Response 200 OK:
		{"jsonrpc":"2.0","result":"ca9b9a66466d730b60047aa28b344a26","id":"1 "}

#### ERROR

/Users/fluffheadsr/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/json/common.rb:148:in `initialize': can't convert nil into String (TypeError)
	from /Users/fluffheadsr/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/json/common.rb:148:in `new'
	from /Users/fluffheadsr/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/json/common.rb:148:in `parse'
	from ./registraion.rb:34:in `<main>'