(2009-12-04 Update: This does not work with RHEL 5.4. The mysql ruby gem requires ruby 1.8.6 and RHEL 5.4 only ships with ruby 1.8.5)

Using yum install ruby and mysql. The command below does not list all the required packages, but due to dependencies, the additional packages will be installed (or should be – this is all from memory).

[bm@app3 ~]$ sudo su -
[root@app3 ~]# yum install ruby ruby-devel ruby-libs ruby-irb \
> ruby-rdoc subversion-ruby mysql-server mysql-devel
[....]

Complete the basic configuration of MySQL.
[root@app3 ~]# /sbin/chkconfig mysqld on
[root@app3 ~]# service mysqld start
[root@app3 ~]# mysql_secure_installation


Download and install RubyGems. As of the date this post was written, the latest version is 1.1.1.
[root@app3 ~]# wget http://rubyforge.org/frs/download.php/35284/rubygems-1.1.1.zip
[root@app3 ~]# unzip rubygems-1.1.1.zip
[root@app3 ~]# cd rubygems-1.1.1
[root@app3 rubygems-1.1.1]# ruby setup.rb
[root@app3 ~]# cd ..
[root@app3 ~]# rm -rf rubygems-1.1.1


Now install Rails, Mongrel, the Ruby MySQL interface, Capistrano
[root@app3 ~]# gem install rails --include-dependencies --no-rdoc --no-ri
[root@app3 ~]# gem install mongrel --include-dependencies --no-rdoc --no-ri
[root@app3 ~]# gem install mysql -- --with-mysql-config=/usr/bin/mysql_config
[root@app3 ~]# gem install capistrano --include-dependencies --no-rdoc --no-ri


Phusion’s passenger gem provides a “mod_rails” module for Apache. The installation is very straight forward.
[root@app3 ~]# gem install passenger
[root@app3 ~]# passenger-install-apache2-module


Just follow the on-screen instructions to finish the installation.