Ideally this process should be automated via Puppet/Chef, I just haven't gotten around to it.
mkdir .ssh
local> cat .ssh/id_rsa.pub | ssh b@B 'cat >> .ssh/authorized_keys'
ssh-keygen -t rsa
cat .ssh/id_rsa.pub
sudo adduser senthil
sudo vim /etc/sudoers
senthil ALL=(ALL:ALL) ALL
sudo apt-get update
sudo apt-get install build-essential zlib1g-dev tcl8.5 libssl-dev libcurl4-openssl-dev git-core bison libreadline-dev tree haproxy openssl libreadline6 libreadline6-dev curl zlib1g libyaml-dev libsqlite3-0 libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev ncurses-dev automake libtool subversion
wget http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p194.tar.gz
tar xzvf ruby-1.9.3-p194.tar.gz
cd ruby-1.9.3-p194
./configure
make
sudo make install
cd ruby-1.9.3-p194
cd ext/psych
ruby extconf.rb
make
sudo make install
See: https://rubygems.org/pages/download
wget http://production.cf.rubygems.org/rubygems/rubygems-1.8.24.tgz
tar xzvf rubygems-1.8.24.tgz
sudo ruby setup.rb
See: https://rvm.io/rvm/install/
curl -L https://get.rvm.io | bash -s stable --ruby
rvm pkg install readline
rvm pkg install zlib
rvm pkg install openssl
rvm install 1.9.3-head
See: http://docs.mongodb.org/manual/tutorial/install-mongodb-on-debian-or-ubuntu-linux/
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10
sudo vim /etc/apt/sources.list.d/10gen.list
deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen
sudo apt-get update
sudo apt-get install mongodb-10gen
sudo gem install pry pry-debugger bundler