A quick HOWTO on how to install Ruby for Rails on Amazon Linux
Check your Ruby version (bundled in Amazon Linux)
ruby -v
ruby 2.0.0p481 (2014-05-08 revision 45883) [x86_64-linux]
Check your sqlite3 version (bundled with Amazon Linux)
sqlite3 --version
3.7.17 2013-05-20 00:56:22 118a3b35693b134d56ebd780123b7fd6f1497668
Check Rubygems version (bundled with Amazon Linux)
gem -v
2.0.14
Install Rails (this sticks on the command line for a while, be patient. The extra parameters exclude the documentation, which if installed, can melt the CPU on smaller instances whilst compiling)
sudo gem install rails --no-ri --no-rdoc
Check Rails installed
rails --version
Rails 4.1.6
Install gcc (always handy to have)
sudo yum install -y gcc
Install ruby and sqlite development packages
sudo yum install -y ruby-devel sqlite-devel
Install node.js (Rails wants a JS interpreter)
sudo bash
curl -sL https://rpm.nodesource.com/setup | bash -
exit
sudo yum install -y nodejs
Install the sqlite3 and io-console gems
gem install sqlite3 io-console
Make a blank app
mkdir myapp
cd myapp
rails new .
Start it (in the background)
bin/rails s &Hit it
wget -qO- http://localhost:3000
Debug (Rails console)
bin/rails c