Ruby on Rails 6: using servers.com cloud as CDN for static assets

deploy.rb

# app/config/deploy.rb

# [...]
namespace :deploy do
  # [...]
  
  desc 'Clear previous assets on server'
  task :clear_shared_assets do
    on roles(:app), in: :sequence, wait: 5 do
      as user: fetch(:user) do
        execute :rm, '-rf', "#{shared_path}/public/assets/*"
        execute :touch, "#{shared_path}/public/assets/manifest"
      end
    end
  end

  desc "Publish assets to CDN"
  task :publish_assets do
    on roles(:app), in: :sequence, wait: 5 do
      within release_path do
        execute(:rails, 'runner lib/services/open_stack/sync.rb', "#{shared_path}/public/assets")
      end
    end
  end

  before :compile_assets,   :clear_shared_assets
  after  :compile_assets,   :publish_assets
  # [...]
end

Gemfile

# [...]

gem 'fog-openstack' # driver for OpenStack Swift v2.0
gem 'non-digest-assets' # build assets without digest

# [...]

production.rb

# app/config/environments/production.rb

Rails.application.configure do
  # [...]
  
  # It's magical set of string that worked
  config.action_controller.asset_host = "your.cnamed.domain"

  config.public_file_server.enabled = false
  config.serve_static_assets = false
  config.assets.compile = false

  config.assets.prefix = '/assets'
  config.assets.compress = true
  config.assets.digest = false
  config.assets.gzip = false
  
  # [...]
end

sync.rb

# app/lib/services/open_stack/sync.rb

path = ARGV.last

uploader = Services::OpenStack::Uploader.new(path)
uploader.call

uploader.rb

# app/lib/services/open_stack/uploader.rb
require 'fog/openstack'

module Services
  module OpenStack
    class Uploader
      def initialize(assets_path)
        @connection = Fog::OpenStack::Storage.new({
          :openstack_username      => 123456,
          :openstack_project_name  => 123456,
          :openstack_api_key       => 'qwerty123456',
          :openstack_auth_url      => 'https://[some_url]:5000/v3',
          :connection_options      => {}
        })

        @server_assets_path = assets_path
        @server_assets_list = Dir[File.join(@server_assets_path, "**/*")].select do |f|
          # If not directory & not *.gz & without digest (need gem 'non-digest-assets')
          File.file?(f) && !f.end_with?('.gz') && !f.match?(/-[0-9a-z]{64}/)
        end
        
        # Bucket/directory (In the Rails is very hard to change default /assets directory)
        @cdn_root_path = 'static/assets'
        @cdn_root_dir  = @connection.directories.create :key => @cdn_root_path
      end

      def upload! server_file_path
        server_file_path_ary   = server_file_path.split('/')
        server_assets_path_ary = @server_assets_path.split('/')

        cdn_file_path = (server_file_path_ary - server_assets_path_ary).join('/')
        @cdn_root_dir.files.create :key => cdn_file_path, :body => File.read(server_file_path)
      end

      def call
        @server_assets_list.each do |item|
          upload! item
          puts "Uploaded: #{item}"
        end
      end

    end
  end
end