Installing ruby-build, ruby, unicorn, bundling and running a rails app on a server

foo.sh

#sudo as necessary

#First, install ruby-build to /opt/ruby-build
git clone git://github.com/sstephenson/ruby-build.git /opt/ruby-build

#it's a good idea to make sure you have these installed before compiling ruby
#apt-get install libssl-dev libreadline6-dev zlib1g-dev

#All ruby installations/versions are going to live in /opt/rubies
mkdir /opt/rubies

#Install version 1.9.3-p392
/opt/ruby-build/bin/ruby-build 1.9.3-p392 /opt/rubies/1.9.3-p392

#You could install another one that will have different gems
/opt/ruby-build/bin/ruby-build 1.9.3-p392 /opt/rubies/myotherversion

#Or a different version
/opt/ruby-build/bin/ruby-build rbx-2.0.0 /opt/rubies/rubinius-2.0.0


#For the one you're going to run the rails app with, install the bundler gem
/opt/rubies/1.9.3-p392/bin/gem install bundler

cd /rails/app #Where your rails app lives
#Tell bundler to install the necessary gems. These will be installed only for the ruby version specified
/opt/rubies/1.9.3-p392/bin/ruby /opt/rubies/1.9.3-p392/bin/bundle #--without test,development

#Install unicorn if it's not part of the gemfile
/opt/rubies/1.9.3-p392/bin/gem install unicorn

#Run the rails app using unicorn
/opt/rubies/1.9.3-p392/bin/ruby /opt/rubies/1.9.3-p392/bin/unicorn -Eproduction -p3456 config.ru

railsapp.conf

#Upstart config

description "Rails w/Unicorn"

start on runlevel [2345]
stop on runlevel [016]

setuid webuser
setgid webuser

chdir /rails/app

respawn
exec /opt/rubies/1.9.3-p392/bin/ruby /opt/rubies/1.9.3-p392/bin/unicorn -Eproduction -p3456 /rails/app/config.ru