取自: 
http://faq.serverdiy.org/read.php?tid=71 
CentOS 5 安裝 ROR 
1. 安裝 RubyWorks 
安裝 RubyWorks Repo 
wget 
http://rubyworks.rubyforge.org/public_key.txt 
sudo rpm --import public_key.txt 
wget 
http://rubyworks.rubyforge.org/RubyWorks.repo 
cp RubyWorks.repo /etc/yum.repos.d/ 
用 yum 安裝 RubyWorks 
yum install rubyworks 出現下面一堆東西,按 y 一直裝完就是了 
[root@vmcentos5 ~]# yum install rubyworks 
安裝好 RubyWorks ,他會把 ruby,rubygems,Mongrel,Haproxy,Monit 安裝跟設定好。但是他不會安裝 Rails ,而是 copy 一份 Rails 在 /usr/rails 上面,這其實是很正確的作法,因為他一開始就取向 Production Server,而 Production Server 本來就該將 Rails 版本 Freeze 在 Rails Doc 裡面。 
[root@vmcentos5 ~]# gem i rails -y 
Bulk updating Gem source index for: 
http://gems.rubyforge.org 
ERROR: While executing gem ... (Gem::GemNotFoundException) 
Could not find rails (> 0) in any repository 
[root@vmcentos5 ~]# 
先不管,再往下安裝 
2. 安裝 MySQL 
RubyWorks 好歸好,就是沒有選擇讓我們裝 DB Server,我們這裡就直接用 yum 安裝 MySQL 
yum install mysql-server 
3. 安裝 Ruby MySQL Native Lib 
我發現到 RubyWorks 並不會安裝 Ruby MySQL Native Lib,所以我們得用 gem 安裝,但是又發現 centos 上面安裝 MySQL Gem 會出現這樣的錯誤訊息,網路上也有人在 complian。 
checking for mysql_query() in -lmysqlclient… no 
checking for main() in -lm… yes 
checking for mysql_query() in -lmysqlclient… no 
checking for main() in -lz… yes 
checking for mysql_query() in -lmysqlclient… no 
checking for main() in -lsocket… no 
checking for mysql_query() in -lmysqlclient… no 
checking for main() in -lnsl… yes 
checking for mysql_query() in -lmysqlclient… no 
*** extconf.rb failed *** 
Could not create Makefile due to some reason, probably lack of 
necessary libraries and/or headers. Check the mkmf.log file for more 
details. You may need configuration options. 
Provided configuration options: 
–with-opt-dir 
所以得先 remove MySQL 然後再重新安裝 MySQL 跟 MySQL Development Lib 
yum remove mysql 
yum install mysql 
yum install mysql-devel 
要在 CentOS 安裝 Rails Gem,那就 
gem i rails -y 即可。 
gem install mysql -- --with-mysql-include=/usr/include/mysql/mysql --with-mysql-lib=/usr/lib/mysql/ 
最後那個步驟,會出現 
[root@vmcentos5 ~]# gem install mysql -- --with-mysql-include=/usr/include/mysql/mysql --with-mysql-lib=/usr/lib/mysql/Select which gem to install for your platform (i386-linux) 
1. mysql 2.7.3 (mswin32) 
2. mysql 2.7.1 (mswin32) 
3. mysql 2.7 (ruby) 
4. mysql 2.6 (ruby) 
5. Skip this gem 
6. Cancel installation 
就選 3 最新的 
至於為何這樣,我也不太清楚。能動就好了。