Bundling

This page is up to date for Rango 0.2.

Bundling is one of the few things where Rango is actually opinionated. The reason is that bundling is real pain in the ass and the only solution which really works is the Bundler.

How Bundler Works

Installation

When you generate new project, you have file called Gemfile in there. Edit it, and when you are happy with the setup, just run gem bundle (this RubyGems command comes from the Bundler). It will install all the required gems for you into your gems directory.

Runtime

The Bundler create gems/environment.rb file for you. When you load the file, it will setup your $LOAD_PATH variable, so you can use Kernel#require to load your dependencies. Or you can do Bundler.require_env(Rango.environment) and it will load all the dependencies which are specified for current Rango.environment or are shared across all the environments. This is the default implementation, check your init.rb.

NOTE: According to Merb Bundler HOWTO, you shouldn’t use require_as: nil, because it’s not supported in current Bundler anymore. Use gem "shotgun", only: :bundle or only(:bundle) if you don’t want to load it on Bundler.require_env.

RubyGems

Thanks to Bundler and its disable_rubygems method you don’t have to use RubyGems in your runtime. Unfortunately RubyGems are loaded by default in Ruby 1.9, so you have to use ruby1.9 --disable-gems in your shebang. This is the default setup in Rango, so you don’t have to care about it.

Installing from gems/cache

task :bundle do
  exec "gem bundle --cached"
end

It might happen that you want to deploy to server where isn’t bundler installed. Solution is easy, just unpack bundler to gems/bundler and create wrapper script which load this bundler and call Gem::Commands::BundleCommand.new.invoke(*ARGV).

#!/usr/bin/env ruby

$LOAD_PATH.unshift File.expand_path(File.join(File.dirname(__FILE__), "..", "gems/bundler/lib"))

require 'rubygems'
require 'rubygems/command'
require 'bundler'
require 'bundler/commands/bundle_command'

Gem::Commands::BundleCommand.new.invoke(*ARGV)

Bundler and Your Own Software

Very often you develop an application and a few plugins, gems and other things you want to use in this app.

gem "foo", git: url
gem "foo", vendored_at

The second solution is great if you need to put debug statements into your plugin etc, but you must to change it before deployment

Links

- Gem Bundler is the Future
- Using the New Gem Bundler Today
- Using the Rubygems Bundler for Your App