Cliente de formulario de login simple con mechanize

client.rb

require 'rubygems'
require 'mechanize'

a = Mechanize.new
a.agent.http.verify_mode = OpenSSL::SSL::VERIFY_NONE
a.get('http://sau/module.php/core/authenticate.php?as=sau') do |login_page|
  
  # Submit the login form
  my_page = login_page.form_with(:name => 'f') do |f|
    f.username  = '******@grammata.es'
    f.password  = '******'
  end.submit
end