generate_tgz.rb

def generate_tgz(filepath, contents)
  tar = StringIO.new
  Gem::Package::TarWriter.new(tar) do |writer|
    writer.add_file(filepath, 0600) do |f|
      f.write(contents)
    end
  end
  tar.seek(0)
  gz = Zlib::GzipWriter.open("#{filepath}.tar.gz") do |gz|
    gz.write(tar.read)
  end
  tar.close
  "#{filepath}.tar.gz"
end