Rack::GitSha

Tiny rack application that serves up the currently deployed git commit SHA.

Inspired by https://github.com/site/sha

Add this line to your application's Gemfile:

gem 'rack-git_sha'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rack-git_sha

If your using rails 3.0+ you can mount the app in your routes.rb file.

MyApp::Application.routes.draw do
  mount Rack::GitSha => '/sha'
end

If your using rack then you can map the middleware in your config.ru.

require 'rack/git_sha'

map '/sha' do
  run Rack::GitSha
end

map '/' do
  run lambda { |env| [200, {'Content-Type' => 'text/plain'}, ['Homepage']] }
end

The argument that is given to #new is the path to the current project, it will default to Dir.pwd if none is given.

After restarting your app, visiting /sha should give you the current git revision.

Once you've got your application serving the current SHA you can do some fun stuff from the command line.

cd example-app
curl -s http://app.example.com/sha
git diff $(curl -fsSL http://app.example.com/sha)

This will do a diff against the deployed sha, showing you what is still pending (much like capistrano's cap deploy:pending:diff).

• Does not work with Heroku.

This gem provides a capistrano task to ensure your app has the required REVISION file for Rack::GitSha to work.

To enable the capistrano task add the following line to your Capfile

require 'capistrano/revision'

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request