Ruby applications use Phusion Passenger as an app server. You can run an application by placing the following in an .htaccess file in your ~/www-root/ directory:

PassengerAppType rack
PassengerAppRoot /users/m/y/mynetid/www-root
PassengerRuby /usr/local/bin/ruby24

PassengerAppRoot should be the full path to the directory where your application's Rack startup file is located.

PassengerRuby should be the full path to your preferred version of Ruby and varies by your silk platform version.

Silk platform Ruby version PassengerRuby value
silkv1 1.9 /opt/rh/ruby193/root/usr/bin/ruby
silkv2 1.9 /usr/local/bin/ruby19
silkv2 2.4 /usr/local/bin/ruby24