This is a skeleton to run Rails in docker-compose, based in Quickstart: Compose and Rails, with some goods:

• A volume for gems (https://medium.com/@fbzga/how-to-cache-bundle-install-with-docker-7bed453a5800#.dmu7m9hf9)
• Spring (https://github.com/jonleighton/spring-docker-example)
• A Guardfile that I like to use

Usage

Just checkout and run ./bootstrap.sh

Guard

This is the list of gems needed to run the example Guardfile:

gem 'spring-commands-rspec'
gem 'guard'
gem 'guard-bundler', require: false
gem 'guard-annotate'
gem 'guard-foreman'
gem 'guard-rspec', require: false
gem 'parallel_tests'

After adding these gems you can use the following command for the web service:

command: bundle exec guard --plugin foreman annotate bundler -i