Installing Ruby on Rails in a Ubuntu/trusty64 Vagrant Box under OS El Capitan

To install Ruby on Rails in a Ubuntu Vagrant Box in a Mac follow the steps below:

1) Download and install vagrant and virtualbox
  - http://www.vagrantup.com/downloads
  - https://www.virtualbox.org/wiki/Downloads

2) Install the Ubuntu box
# vagrant init ubuntu/trusty64

4) Set up the forwarding

# vi Vagrantfile

Add the line in the forwarded port mapping

config.vm.network "forwarded_port", guest: 3000, host: 3030, protocol: 'tcp', auto_correct: true

5) Runing Ubuntu

# vagrant up --provider virtualbox
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Checking if box 'ubuntu/trusty64' is up to date...
==> default: Clearing any previously set forwarded ports...
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
    default: Adapter 1: nat
==> default: Forwarding ports...
    default: 3000 (guest) => 3030 (host) (adapter 1)
    default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
    default: SSH address: 127.0.0.1:2222
    default: SSH username: vagrant
    default: SSH auth method: private key
==> default: Machine booted and ready!
==> default: Checking for guest additions in VM...
    default: The guest additions on this VM do not match the installed version of
    default: VirtualBox! In most cases this is fine, but in rare cases it can
    default: prevent things such as shared folders from working properly. If you see
    default: shared folder errors, please make sure the guest additions within the
    default: virtual machine match the version of VirtualBox you have installed on
    default: your host and reload your VM.
    default: 
    default: Guest Additions Version: 4.3.34
    default: VirtualBox Version: 5.0
==> default: Mounting shared folders...
    default: /vagrant => /Users/sergio/vagrant_boxes
==> default: Machine already provisioned. Run `vagrant provision` or use the `--provision`
==> default: flag to force provisioning. Provisioners marked to run always will still run.


6) Access the virtual machine
# vagrant ssh

Now it's time to install Ruby on Rails. Follow the next steps_
1) Installing dependencies

# cd
# sudo apt-get update
# sudo apt-get install git-core curl zlib1g-dev build-essential libssl-dev libreadline-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt1-dev libcurl4-openssl-dev python-software-properties libffi-dev

2) Installing Ruby dev packages

# sudo apt-get install ruby-all-dev
# sudu updatedb

3) Installing rbenv

# cd
# git clone git://github.com/sstephenson/rbenv.git .rbenv
# echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
# echo 'eval "$(rbenv init -)"' >> ~/.bashrc
# exec $SHELL

# git clone git://github.com/sstephenson/ruby-build.git ~/.rbenv/plugins/ruby-build
# echo 'export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH"' >> ~/.bashrc
# exec $SHELL

# git clone https://github.com/sstephenson/rbenv-gem-rehash.git ~/.rbenv/plugins/rbenv-gem-rehash

# rbenv install 2.2.3
# rbenv global 2.2.3
# ruby -v

4) If you want to avoid installing the packages documentation execute the following commands

# echo "gem: --no-ri --no-rdoc" > ~/.gemrc
# gem install bundler

4) Installing NodeJS

# curl -sL https://deb.nodesource.com/setup_4.x | sudo -E bash -
# sudo apt-get install -y nodejs

5) Installing Rails

# gem install rails -v 4.2.4
# rails -v

6) Set up PostgreSQL

# sudo sh -c "echo 'deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main' > /etc/apt/sources.list.d/pgdg.list"

# wget --quiet -O - http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | sudo apt-key add -

# sudo apt-get update
# sudo apt-get install postgresql-common
# sudo apt-get install postgresql-9.3 libpq-dev

7) Create a PostgrSQL user

# sudo -u postgres createuser INSERT_THE_USERNAME_HERE -s
# sudo -u postgres psql
postgres=# \password INSERT_THE_USERNAME_HERE

Now it is time to check the installation creating a rails application.

1) We will use sqlite in this case

# rails new myapp

If you want to use your PostgreSQL server use instead

# rails new myapp -d postgresql 

2) Go to the new app and create the database

# cd myapp
# rake db:create

3) Run the rails server

# rails s -b 0.0.0.0
=> Booting WEBrick
=> Rails 4.2.4 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2016-01-03 16:53:10] INFO  WEBrick 1.3.1
[2016-01-03 16:53:10] INFO  ruby 1.9.3 (2013-11-22) [x86_64-linux]
[2016-01-03 16:53:10] INFO  WEBrick::HTTPServer#start: pid=1956 port=3000


4) Check the server from your local machine at port 3030: http://127.0.0.1:3030

Hope help!