helder/ruby-onbuild repository overview

⁠Docker ruby (onbuild)

Based on helder/ruby⁠ image (adds utf-8 locale to official images), assumes there's a Gemfile (and maybe Gemfile.lock) in current directory.

⁠Basic usage

Let´s say you have the files:

.
└── theme
    ├── Gemfile
    └── Gemfile.lock

Add a theme/Dockerfile with:

FROM helder/ruby-onbuild:2.2

After building, you'll have an image with all your ruby dependencies installed:

docker build -t yourimage theme

⁠Example with docker-compose and compass

Assuming the example above, add something like this to your docker-compose.yml:

compass:
  build: theme
  command: compass watch
  volumes:
    - theme:/app
  working_dir: /app

This will build your ruby dependencies to an image (compass being one of those), set the working directory to where you want to run compass in, and watch for changes.