A Virtual Machine for Ruby on Rails Core Development

Introduction

This project automates the setup of a development environment for Ruby on Rails core development. This is the easiest way to build a box with everything ready to start hacking on your pull request, all in an isolated virtual machine.

Requirements

How To Build The Virtual Machine

Building the virtual machine is this easy:

host $ git clone https://github.com/rails/rails-dev-box.git
host $ cd rails-dev-box
host $ vagrant up

That's it.

If the base box is not present that command fetches it first. The setup itself takes about 3 minutes in my MacBook Air. After the installation has finished, you can access the virtual machine with

host $ vagrant ssh
Welcome to Ubuntu 12.04 LTS (GNU/Linux 3.2.0-23-generic-pae i686)
...
vagrant@rails-dev-box:~$

Port 3000 in the host computer is forwarded to port 3000 in the virtual machine. Thus, applications running in the virtual machine can be accessed via localhost:3000 in the host computer.

What's In The Box

Git
RVM
Ruby 2.0.0 (binary RVM install)
Bundler
SQLite3, MySQL, and Postgres
System dependencies for nokogiri, sqlite3, mysql, mysql2, and pg
Databases and users needed to run the Active Record test suite
Node.js for the asset pipeline
Memcached

Recommended Workflow

The recommended workflow is

edit in the host computer and
test within the virtual machine.

Just clone your Rails fork in the very directory of the Rails development box in the host computer:

host $ ls
README.md   Vagrantfile puppet
host $ git clone git@github.com:<your username>/rails.git

Vagrant mounts that very directory as /vagrant within the virtual machine:

vagrant@rails-dev-box:~$ ls /vagrant
puppet  rails  README.md  Vagrantfile

so we are ready to go to edit in the host, and test in the virtual machine.

This workflow is convenient because in the host computer you normally have your editor of choice fine-tuned, Git configured, and SSH keys in place.

Virtual Machine Management

When done just log out with ^D and suspend the virtual machine

host $ vagrant suspend

then, resume to hack again

host $ vagrant resume

Run

host $ vagrant halt

to shutdown the virtual machine, and

host $ vagrant up

to boot it again.

You can find out the state of a virtual machine anytime by invoking

host $ vagrant status

Finally, to completely wipe the virtual machine from the disk destroying all its contents:

host $ vagrant destroy # DANGER: all is gone

Please check the Vagrant documentation for more information on Vagrant.