Automatic HTTP Basic Authentication In Ruby on Rails

Well, you may want to use HTTP basic auth mechanism of Net::HTTP library.
Basically this is how i would do it:

require 'net/http'

req = Net::HTTP::Post.new(url.path)
req.basic_auth("username","password")
req.body = xml_query # contents the raw query
req.content_type = "application/x-www-form-urlencoded"
req.content_length = xml_query.length

    result = nil
    begin
      timeout(3) do
        _result = Net::HTTP.new(url.host,url.port).start { |http|
http.request(req)}
        result = _result.body
      end
    rescue Timeout::Error
      result = nil
    rescue
      result = nil
    end

But probably you want a much simpler solution, another solution would
be to use SimpleHttp library.

str = SimpleHttp.get URI.parse("http://username:password@www.example.com")

URL:

http://simplehttp.rubyforge.org/