Compass "watch" docker container

Based on https://github.com/antonienko/compass-watch-docker-container but using Alpine Linux instead of Ubuntu.

The purpose is to compile sass or scss files using the compass open-source CSS Authoring Framework

Developed as an addition to Docker4Drupal and intended to be left running on your development machine, so every changes to sass sources, CSS will be compiled to the output folder you configure in the config.rb file.

How to use this image

Setup

First, you need to configure your folders in a config.rb file, placed on the sass root folder. Here's an example folder structure, and its corresponding config.rb file.

Folder structure:

/src
  /compass
    /sass
    config.rb
  /app
  /public
    /css

config.rb file:

# Require any additional compass plugins here.

#Folder settings
css_dir = "../public/css"          #where the CSS will saved
sass_dir = "sass"           #where our .scss files are
images_dir = "../public/img"    #the folder with your images

# You can select your preferred output style here (can be overridden via the command line):
output_style = :expanded # After dev :compressed

# To disable debugging comments that display the original location of your selectors. Uncomment:
line_comments = true

# Obviously
preferred_syntax = :scss

Note I was unable to get additional compass plugins to load so I have baked in the ones I required to the Dockerfile

Manual CSS Compilation

docker run -v $(pwd):/src dedavidson/compass-watch compile /src/some-folder/another-folder --force

Watching for sass Changes

Using docker run

docker run -d -v /src:/src dedavidson/compass-watch watch --poll /src/compass

Using docker compose

compass:
  build: dedavidson/compass-watch
  command: watch --poll /src/compass
  volumes:
    - /src:/src