What you need:

Fedora Core 4 installed
Apache httpd 2.0.54 installed
Connection to Internet
Access to root Login (otherwise you will just end up frustrating yourself)

I am using Plesk 8.0.1 to manage my domains. So some of the configuration settings will be specific to that. But it will also work on a simple Linux Box just as well.

Now that we have established what we need, lets get cracking.

Installing Ruby, Gems and Rails:

The Ruby RPM should come by default with your Fedora Core install. So to install Ruby, simply execute the following as root:

yum install ruby
yum install ruby-devel
yum install rdoc
yum install irb

mkdir /var/www/downloads
cd /var/www/downloads
wget <a href="http://rubyforge.org/frs/download.php/11289/rubygems-0.9.0.tgz">http://rubyforge.org/frs/download.php/11289/rubygems-0.9.0.tgz</a>
tar xvf rubygems-0.9.0.tgz
cd rubygems-0.9.0
ruby setup.rb

cd ..
rm ruby* -drf

gem install rails --include-dependencies

Now that you are done with Ruby, Gems and Rails, next bit is to download latest SCGI source and build the mod_scgi.so Apache module.

Firstly, you will need the Apache httpd Development stuff.

yum install httpd-devel
cd /var/www/downloads
wget <a href="http://www.mems-exchange.org/software/scgi/scgi-1.10.tar.gz">http://www.mems-exchange.org/software/scgi/scgi-1.10.tar.gz</a>
tar xvf scgi-1.10.tar.gz
cd scgi-1.10/apache2
apxs -i -c mod_scgi.c

Next, copy the mod_scgi.so file into your Apache modules directory.

After this, you will need the mod_scgi.so module to be loaded. For this, add the following to your Apache httpd.conf:

LoadModule scgi_module modules/mod_scgi.so

Before we can make use of the Apache SCGI module, we will need to install the SCGI gem.

Before that, install the following 2 gems:

• cmdparse 2.0.0 or greater
• highline 1.0.1 or greater

cd /var/www/downloads
wget <a href="http://www.zedshaw.com/downloads/scgi_rails/scgi_rails-0.4.3.gem">http://www.zedshaw.com/downloads/scgi_rails/scgi_rails-0.4.3.gem</a>
gem install scgi_rails-0.4.3.gem

All the installations are done. Now, lets create a rails application and make it available over the internet.

rails myapp
cd myapp
scgi_ctrl config
<provide a password for configuration>

httpd.conf VirtualHost example configuration:

<VirtualHost your-ip:80>
    AddDefaultCharset utf-8
    ServerName <a href="http://www.yourdomain">www.yourdomain</a>
    DocumentRoot /your-switchtower-root/current/public
    ErrorDocument 500 /500.html
    ErrorDocument 404 /404.html
    # handle all requests throug SCGI
    SCGIMount /myapp 127.0.0.1:9999
    # matches locations with a dot following at least one more characters, that is, things like   *,html, *.css, *.js, which should be delivered directly from the filesystem
    <LocationMatch \..+$>
        # don't handle those with SCGI
        SCGIHandler Off
    </LocationMatch>
    <Directory /your-switchtower-root/current/public/>
        Options +FollowSymLinks
        AllowOverride All
        Order allow,deny
        allow from all
    </Directory>
</VirtualHost>

Your public/.htaccess file should look like:

Options +FollowSymLinks +ExecCGI

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ /rails/dispatch.cgi/$1 [QSA,L]

ErrorDocument 500 "<h2>Application error</h2>Rails application failed to start properly" 

We are now ready to show off our rails app to the world.

Start SCGI.

cd myapp
nohup scgi_ctrl start &

Time to restart Apache so that the new configuration becomes available. Execute the following as root:

apachectl restart

Visit the URL of your site and you should see the welcome screen. Next, visit URL/myapp and the rails app should be available there.

I spent many sleepless frustrating nights to eventually get it all working. Hope the above configuration saves a lot of people from same amount of frustration.

FYI, the latest version of SCGI (1.11) appears to be located here – the MEMS site appears out-of-date.

Original topic at PuneRuby
Ashish Kulkarni – ashish@sapforbusiness.com
Blog

See Also:

• HowToConfigureRailsOnWindowsApacheSCGI