apachectl -M
    passenger_module (shared)

    tail conf/httpd.conf
    LoadModule passenger_module /opt/passenger-3.0.21/ext/apache2/mod_passenger.so
    PassengerRoot /opt/passenger-3.0.21
    PassengerRuby /usr/bin/ruby

    cat conf.d/passenger.conf
       <VirtualHost *:80>
          ServerName puppet-master-1-agent-18.example.com
          DocumentRoot /var/www/html/riemann-dash/lib/riemann/dash/public
          <Directory /var/www/html/riemann-dash/lib/riemann/dash/public>
             # This relaxes Apache security settings.
             AllowOverride all
             # MultiViews must be turned off.
             Options -MultiViews
          </Directory>
       </VirtualHost>

    ls /var/www/html/
    riemann-dash