Satya's blog - Rails 3 on Ubuntu with RVM

(See old article http://www.thesatya.com/blog/2011/05/rails3_upgrade.html )

sudo apt-get install git-core curl libmysql-ruby 

sudo apt-get install libmysqlclient-dev libsqlite3-dev

Install rvm from the rvm website, usually with something like:

curl -L get.rvm.io | bash -s stable

also add to your .bashrc or equivalent:

[[ -s ~/.rvm/scripts/rvm ]] && source ~/.rvm/scripts/rvm

Install pre-requisites, and ruby, and set the default ruby:

rvm pkg install zlib
rvm install 1.9.2 #or 1.9.3
rvm default 1.9.2

Then you can put .rvmrc files in your project directory (or a new directory) containing something like:

rvm use ruby-1.9.2-p180@my_gemset_name --create

Then you can set up a Gemfile, and then run:

gem install bundler
bundle install