Isolate is a very simple RubyGems sandbox. It provides a way to express and automatically install your project's Gem dependencies.
When Isolate runs, it uses GEM_HOME, GEM_PATH, and a few other tricks to separate your code from the system's RubyGems configuration, leaving it free to run in blissful solitude.
Isolate is very, very, very stupid simple. For a much more full-featured Gem bundler, check out Yehuda Katz and Carl Lerche's Bundler: It does a lot of fancy AOT dependency resolution, supports non-gem (including git) resources, and is probably a better fit for you.
RubyGems 1.3.6 or better, Ruby 1.8.6 or better.
require "rubygems" require "isolate/now"
gem "rails", "2.3.5" gem "aasm", "2.0.0" env :development, :test do gem "sqlite3-ruby", "1.2.5" end env :production do gem "memcached", "0.19.2" end
Try running rake environment. Before anything else happens, Isolate will make sure you have copies of every gem you need (extend the example above to cover all your dependencies). If they're already installed on your system Isolate will use them, otherwise a private copy will be installed under tmp/isolate.
require "rubygems" require "isolate/now"
Construct your Isolate file as above. Be sure to remove any references to Bundler.setup and Bundler.require from config/boot.rb and config/application.rb.
Sinatra, Rack, and Anything Else
There's nothing special about Rails, it's just an easy first example. You can use Isolate with any library or framework by simply putting an Isolate file in the root of your project and requiring isolate/now as early as possible in the startup process.
When you're starting up, Isolate tries to determine its environment by looking at the ISOLATE_ENV, RACK_ENV, and RAILS_ENV env vars. If none are set, it defaults to development.
If you're using Hoe to manage your library, you can use Isolate's Hoe plugin to automatically install your lib's development, runtime, and test dependencies without polluting your system RubyGems, and run your tests/specs in total isolation.
Assuming you have a recent Hoe and isolate's installed, it's as simple as putting:
before the Hoe.spec call in your Rakefile.
If you're not using Hoe, you can use an Isolate.now! block at the top of your Rakefile. See the RDoc for details.
Isolate provides a few useful Rake tasks. If you're requiring isolate/now, you'll get them automatically when you run Rake. If not, you can include them by requiring isolate/rake.
This task shows you the current Isolate settings and gems.
$ rake isolate:env path: tmp/isolate/ruby-1.8 env: development files: Isolate cleanup? true enabled? true install? true multiruby? true system? true verbose? true [all environments] gem rails, = 2.3.5 gem aasm, = 2.0.0 [development, test] gem sqlite3-ruby, = 1.2.5 [production] gem memcached, = 0.19.2
This task allows you to run a subshell or a command in the isolated environment, making any command-line tools available on your PATH.
# run a single command in an isolated subshell $ rake isolate:sh['gem list'] # run a new isolated subshell $ rake isolate:sh
This task lists gems that have a more recent released version than the one you're using.
$ rake isolate:stale aasm (2.0.0 < 2.1.5)
require "isolate/now" is sugar for Isolate.now!, which creates, configures, and activates a singleton version of Isolate's sandbox. Isolate.now! takes a few useful options, and lets you define an entire environment inline without using an external file.
For detailed information on Isolate.now! and the rest of the public API, please see the RDoc.
Not Gonna Happen
Dependency resolution. If this ever becomes a serious problem for us, we'll likely push hard to solve it in RubyGems proper. If you run into these sorts of problems a lot, use Bundler. Or less libraries.
Autorequire. Unlike config.gems or other solutions, Isolate expects you to be a good little Rubyist and manually require the libraries you use.
Support for Git or other SCMs. You're welcome to write an extension that supports 'em, but Isolate itself is focused on packaged, released gems.
$ gem install isolate
#isolate on Freenode
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