Spinning up a new Rails app

So people have been attempting to get a Rails app up and running recently. I also have some apps in development on Rails 3, so I've been experiencing some of the same problems many others have.

The other night, I worked with sferik to start porting merb-admin over to Rails. Because this process involved being on edge Rails, we got the process honed to a very simple, small, repeatable process.

The Steps

Step 1: Check out Rails

$ git clone git://github.com/rails/rails.git

Step 2: Generate a new app

$ ruby rails/railties/bin/rails new_app
$ cd new_app

Step 3: Edit the app's Gemfile

# Add to the top
directory "/path/to/rails", :glob => "{*/,}*.gemspec"  
git "git://github.com/rails/arel.git"  
git "git://github.com/rails/rack.git"  

Step 4: Bundle

$ gem bundle

Done

Everything should now work: script/server, script/console, etc.

If you want to check your copy of Rails into your app, you can copy it into the app and then change your Gemfile to point to the relative location.

For instance, if you copy it into vendor/rails, you can make the first line of the Gemfile directory "vendor/rails", :glob => => "{/,}.gemspec". You'll want to run gem bundle again after changing the Gemfile, of course.