Using open-uri Ruby library to open http websites is really easy:

begin
  io_thing = open(self.check_url.to_s)
  io_thing.status[0] == '200'
rescue Exception => e
  false
end

Things get itchy when we want to visit a HTTPS (SSL) self-signed website. Some of them have them corrupted (or expired). Open-uri raises an exception when it occures one of them. To skip certificates testing and get the page we need to turn off certificates verification:

module OpenSSL
  module SSL
    remove_const :VERIFY_PEER
  end
end
OpenSSL::SSL::VERIFY_PEER = OpenSSL::SSL::VERIFY_NONE

However remember to do this carefully, because this can we a security thread to your software.