rails subsite

gistfile1.txt

def config_site(site)
    paths = Rails::Paths::Root.new(Rails.root.join("site_#{site}"))
    paths.add "app",                 eager_load: true, glob: "*"
    paths.add "app/assets",          glob: "*"
    paths.add "app/controllers",     eager_load: true
    paths.add "app/helpers",         eager_load: true
    paths.add "app/models",          eager_load: true
    paths.add "app/mailers",         eager_load: true
    paths.add "app/views"
    paths.add "app/controllers/concerns", eager_load: true
    paths.add "app/models/concerns",      eager_load: true
    paths.add "config/locales",      glob: "*.{rb,yml}"

    ActionController::Base.class_eval do
      self.prepend_view_path paths["app/views"]
    end
    ActionMailer::Base.class_eval do
      self.prepend_view_path paths["app/views"]
    end
    ActiveSupport::Dependencies.autoload_paths.unshift(*(paths.autoload_paths + paths.eager_load + paths.autoload_once).uniq)
    ActiveSupport::Dependencies.autoload_once_paths.unshift(*paths.autoload_once)

    Rails.application.config.i18n.railties_load_path.concat(paths["config/locales"].existent)
    Rails.application.config.assets.paths.unshift(*paths["app/assets"].existent_directories)
    Rails.application.config.assets.precompile += [
      Proc.new { |path, fn|
        fn =~ /site_#{site}\/app\/assets/ && !%w(.js .css).include?(File.extname(path))
     },
     /(?:\/|\\|\A)application\.(css|js)$/
    ]
end

in Rails project

/site_xyz/app/[assets|controllers|models|helpers|views]
/site_xyz/config/locales

in an initializer

config_site('xyz')