```ruby
require 'rake'

module Commands
  class Raker
    include Rake::DSL

    def initialize
      load_rake_tasks
    end

    def rake(task = nil, *args)
      task.nil? ? print_rake_tasks : invoke_rake_task(task, *args)
      "Completed"
    rescue SystemExit, RuntimeError => e
      "Failed: #{e.message}"
    end
    
    
    private
      def load_rake_tasks
        Rake::TaskManager.record_task_metadata = true # needed to capture comments from define_task
        load Rails.root.join('Rakefile')
      end
      
      def print_rake_tasks
        Rake.application.options.show_tasks = :tasks
        Rake.application.options.show_task_pattern = Regexp.new('')
        Rake.application.display_tasks_and_comments
      end

      def invoke_rake_task(task, *args)
        Rake::Task[task].invoke(*args)
        Rake.application.tasks.each(&:reenable) # Rake by default only allows tasks to be run once per session
      end
  end
end```

Allow you to set Rake ENV options as part of the call (still missing a way to set rake options like --trace)
user
```ruby
require 'rake'

module Commands
  class Raker
    include Rake::DSL

    def initialize
      load_rake_tasks
    end

    def rake(task = nil)
      task.nil? ? print_rake_tasks : invoke_rake_task(task)
      "Completed"
    rescue SystemExit, RuntimeError => e
      "Failed: #{e.message}"
    end
    
    
    private
      def load_rake_tasks
        Rake::TaskManager.record_task_metadata = true # needed to capture comments from define_task
        load Rails.root.join('Rakefile')
      end
      
      def print_rake_tasks
        Rake.application.options.show_tasks = :tasks
        Rake.application.options.show_task_pattern = Regexp.new('')
        Rake.application.display_tasks_and_comments
      end

      def invoke_rake_task(task)
        task, *options = task.split(" ")

        ARGV.replace options

        # FIXME: Before we can use this, we need a way to reset the options again
        # Rake.application.handle_options

        expose_argv_arguments_via_env { Rake::Task[task].invoke }
        Rake.application.tasks.each(&:reenable) # Rake by default only allows tasks to be run once per session
      ensure
        ARGV.replace([])
      end
      
      def expose_argv_arguments_via_env
        argv_arguments.each { |key, value| ENV[key] = value }
        yield
      ensure
        argv_arguments.keys.each { |key| ENV.delete(key) }
      end
      
      def argv_arguments
        ARGV.each_with_object({}) do |arg, arguments|
          if arg =~ /^(\w+)=(.*)$/
            arguments[$1] = $2
          end
        end
      end
  end
end```
assistant