Redmine

I'm creating a plugin and i'm finding trouble with the REST API
When I use this code:

  class PollsController < ApplicationController
    unloadable

    before_filter :check_if_login_required
    before_filter :verify_authenticity_token
    before_filter :find_project, :authorize, :only => [:index, :vote]#, :print]
    accept_api_auth :index, :vote, :print

    def index
         @project = Project.find(params[:project_id])
         @polls = Poll.all # @project.polls
    end

    def print

        require 'odf-report'
        require 'open-uri'

        @apiKey = User.current.api_key

        url = 'http://redmine.lab.ic.unicamp.br:8080/users.json?key=' + @apiKey
        #url = 'http://www.json-generator.com/api/json/get/cuLKyfYKOG'

        @result = JSON.parse(open(url).read)

        report = ODFReport::Report.new(Rails.root.join('plugins', 'polls', 'ODT', 'test_users.odt')) do |r|
                r.add_section("USUARIO", @result['users']) do |s|
                    s.add_field(:firstname)
                    s.add_field(:lastname)
                end
        end

        send_data report.generate,
            type: 'application/vnd.oasis.opendocument.text',
            disposition: 'attachment',
            filename: 'relatorio_usuarios.odt'

    end

    #private

    def find_project
        @project = Project.find(params[:project_id])
    end
end

I get error 500 internal (TIMEOUT)

and when accessing the same JSON, but outside the server, using this json:
url = 'http://redmine.lab.ic.unicamp.br:8080/users.json?key=' + @apiKey

  url = 'http://www.json-generator.com/api/json/get/cuLKyfYKOG'

it works.

Im using ruby 1.9.3p484, Rails 4.2.3 and redmine 3.0.4

How can I fix it?