Simple Jekyll plugin for creating a CDN url Liquid tag

_config.yml

#cdn
cdnurl: 'https://s3-eu-west-1.amazonaws.com/outoftime/'

cdn_url_tag.rb

module Jekyll
  class CdnUrlTag < Liquid::Tag

    def initialize(tag_name, text, tokens)
      super
      @path = text
    end

    def render(context)
      resolvedPath = ''
      
      # Check if @path is actually a name of a variable or just a textual path.
      if !context[@path].nil?
        resolvedPath = context[@path]
      else 
        resolvedPath = @path
      end
      
      # Strip the leading slash if there's any.
      if resolvedPath.start_with?('/')
        resolvedPath = resolvedPath[1..-1]
      end
      
      "#{context.registers[:site].config['cdnurl']}#{resolvedPath}"
    end
  end
end

Liquid::Template.register_tag('cdn_url', Jekyll::CdnUrlTag)