Heroku Ruby Jekyll Buildpack is a fork of Heroku's official Ruby buildpack with added support for generating static Jekyll sites during the build/deployment stage.
With this buildpack you no longer need pre-build the site or commit the _site build directory to your repo. This simplifies the deployment process and keeps the repo clean. All of the standard Ruby tools are maintained in this buildpack, so you can take full advantage of Rack middleware and other useful tools from the Ruby ecosystem.
heroku create --buildpack http://github.com/galois17/heroku-buildpack-ruby-jekyll.git
or add this buildpack to your current app
heroku config:add BUILDPACK_URL=http://github.com/galois17/heroku-buildpack-ruby-jekyll.git
Create a Ruby web app with dependencies managed by Bundler and a Jekyll site. Heroku-Jekyll-Hello-World can be used as a sample starter.
git push heroku master
Watch it "Building jekyll site"
-----> Fetching custom git buildpack... done
-----> Ruby/Rack app detected
-----> Installing dependencies using Bundler version 1.3.0.pre.5
Running: bundle install --without development:test --path vendor/bundle --binstubs vendor/bundle/bin --deployment
Using posix-spawn (0.3.6)
Using albino (1.3.3)
Using fast-stemmer (1.0.0)
Using classifier (1.3.3)
Using daemons (1.1.4)
Using directory_watcher (1.4.1)
Using eventmachine (0.12.10)
Using kramdown (0.13.3)
Using liquid (2.3.0)
Using syntax (1.0.0)
Using maruku (0.6.0)
Using jekyll (0.11.0)
Using rack (1.3.5)
Using rack-contrib (1.1.0)
Using rack-rewrite (1.2.1)
Using thin (1.3.1)
Using bundler (1.3.0.pre.5)
Your bundle is complete! It was installed into ./vendor/bundle
Cleaning up the bundler cache.
Would have removed bundler (1.2.1)
Building jekyll site
Configuration from /tmp/build_2khwpm40t8wev/_config.yml
Building site: . -> ./_site
Successfully generated site: . -> ./_site
-----> Discovering process types
Procfile declares types -> web
Default types for Ruby/Rack -> console, rake
-----> Compiled slug size: 6.1MB
-----> Launching... done, v99
-----> Deploy hooks scheduled, check output in your logs
http://yoursite.herokuapp.com deployed to Heroku
The blog post introducing this buildpack: http://mwmanning.com/2011/11/29/Run-Your-Jekyll-Site-On-Heroku.html.