I installed Redmine v0.9.4 on a 32-bit CentOS 5.5 box. The following versions were used:

* Ruby v1.8.7
* RubyGems 1.3.7
* Rails v2.3.5
* Passenger v2.2.14

You'll need a MySQL database ready, so set it up and make a note of the username and password. There are quite a few steps involved, so let's go!

## Pre-Flight

    yum install httpd-devel openssl-devel zlib-devel gcc gcc-c++ curl-devel expat-devel gettext-devel ImageMagick ImageMagick-devel mysql-devel

You *may* have issues with `mysql-devel`. In this case,

    yum remove mysql
    yum install mysql mysql-devel mysql-server

## Step 1: Compile and Install Ruby

The FTP site is at <ftp://ftp.ruby-lang.org//pub/ruby/1.8/>

    wget ftp://ftp.ruby-lang.org//pub/ruby/1.8/ruby-1.8.7.tar.gz
    tar -xzvf ruby-1.8.7.tar.gz
    sudo ./configure --enable-shared --enable-pthread
    make
    make install

The weird thing is that you now have to tell Ruby about `zlibs` and re-compile. In the compilation folder:

    cd ext/zlib
    ruby extconf.rb --with-zlib-include=/usr/include --with-zlib-lib=/usr/lib
    cd ../../
    sudo make
    sudo make install

Test this:

    [root@pdb-d rubygems-1.3.7]# ruby --version
    ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-linux]

## Step 2: Install [RubyGems](http://rubygems.org/pages/download)

    wget http://production.cf.rubygems.org/rubygems/rubygems-1.3.7.tgz
    sudo tar xzvf rubygems-1.3.7.tgz
    cd rubygems-1.3.7
    sudo ruby setup.rb

Now check with:

    [root@pdb-d rubygems-1.3.7]# gem -v
    1.3.7

## Step 3: Install Rails

Note the version! Redmine requires Rails 2.3.5. So:

    gem install rails -v=2.3.5

## Step 4: Install the MySQL gem

    gem install mysql -- --with-mysql-config=/usr/bin/mysql_config

## Step 5: Install Passenger

Any Rails application can use a bunch of servers. [Mongrel](http://rubyforge.org/projects/mongrel/) is an example; it runs completely independent of Apache. [Passenger](http://www.modrails.com/) runs Rails apps on top of Apache (as a module) is amazing w.r.t. the simplicity of its setup and debugging.

    gem install passenger
    passenger-install-apache2-module

Now add an `httpd` directive called `/etc/httpd/conf.d/passenger.conf`. Here are the contents:

    LoadModule passenger_module /usr/local/lib/ruby/gems/1.8/gems/passenger-2.2.14/ext/apache2/mod_passenger.so
    PassengerRoot /usr/local/lib/ruby/gems/1.8/gems/passenger-2.2.14
    PassengerRuby /usr/local/bin/ruby

Restart the `httpd` service.

## Step 6: Install Redmine

I'm choosing to install Redmine in `/opt`.

    svn checkout http://redmine.rubyforge.org/svn/tags/0.9.3/ /opt/redmine
    chmod 777 /opt/redmine/files

* Configure `/opt/redmine/config/database.yml` to reflect your
    database parameters.
* Configure `/opt/redmine/config/email.yml` to reflect your
    email parameters.

## Tell Passenger to run Redmine!

AFAIK, any Rails app will have a `public` folder that 'kickstarts' the application (again, don't know anything about this; seems like it to me.) I created a `/opt/redmine/public/.htaccess` file and added this:

    PassengerAppRoot /opt/redmine

Now I just symlinked the `/opt/redmine/public` to my Apache root, restarted `httpd`, and was good to go at <http://localhost/redmine>

    ln -s /opt/redmine/public /var/www/html/redmine

## Sources

* [Installing Rails on CentOS
    5](http://www.catapult-creative.com/2009/02/04/installing-rails-on-centos-5/)
* [Deploying a Rails Application with
    Passenger](http://wiki.ocssolutions.com/Deploying_a_Rails_Application_With_Passenger)