I am using apache passenger to deploy rails application.
I have followed each and every step clearly and everything works fine. No error message in deployment.
Make sure that your vhost lives somewhere in /etc/apache2/sites-available, and then make sure to add it to apache, either by using the a2ensite command, or by manually symlinking /etc/apache2/sites-enabled/your_vhost_name_here to whatever you called the site.
Possible commands to enable the site (use either one):
sudo a2ensite your_vhost_name
sudo ln -s /etc/apache2/sites-available/your_vhost_name /etc/apache2/sites-enabled
After you've done this, make sure to reload apache, by running the following command:
sudo service apache2 restart