This library is called apache_configuration_maker. It is supposed to create a valid httpd.conf file. For now, it will generate a valid httpd.conf file only for my own needs, but I am willing to adapt it to fit to your needs, if you are specific in what you want to see in this library.
Gemfile gem 'apache_configuration_maker', '~> 0.0.3'
install gem install apache_configuration_maker -v 0.0.3