Installing mod_rails on Ubuntu Hardy

First, install these packages using apt-get or aptitude:

• ruby
• rubygems
• ruby1.8-dev
• build-essential
• apache2-mpm-prefork
• apache2-prefork-dev

Add the following line to /etc/bash.bashrc

export PATH=$PATH:/var/lib/gems/1.8/bin

Install mod_rails (passenger) using gem:

gem update
gem install passenger

Run passenger-install-apache2-module to checks for prerequisites and build the necessary modules. It’s important to note the highlighted output that begins with LoadModule, because we’ll be pasting that directly into an apache configuration file later. If you let the info get away from you, it’s fine to run the install again.

Now it’s time to configure the server. I prefer not to touch the original configuration files, so I create the file /etc/apache2/conf.d/passenger.conf with the information provided by passenger-install-apache2-module. The contents are similar to this:

# DON'T USE THIS. USE THE OUTPUT FROM passenger-install-apache2-module ON YOUR SERVER
LoadModule passenger_module /var/lib/gems/1.8/gems/passenger-2.0.3/ext/apache2/mod_passenger.so
PassengerRoot /var/lib/gems/1.8/gems/passenger-2.0.3
PassengerRuby /usr/bin/ruby1.8

Finally, we need a virtual host configuration for you application. Put this in /etc/apache2/sites-available/sitename. This is very close to the sample provided by passenger-install-apache2-module, but I’ve added the rewrite rule that allows ‘cap deploy:web:[dis|en]able’ to operate.

<VirtualHost *:80>
  ServerName www.yourhost.com
  DocumentRoot /somewhere/public

  RewriteEngine On

  # Check for maintenance file and redirect all requests
  RewriteCond %{DOCUMENT_ROOT}/system/maintenance.html -f
  RewriteCond %{SCRIPT_FILENAME} !maintenance.html
  RewriteRule ^.*$ /system/maintenance.html [L]
</VirtualHost>

Run the commands a2dissite default and a2ensite sitename to turn the site on, and a2enmod rewrite to turn on the rewrite module. Once you restart apache, your application should Just Work™.