How do I run Rake tasks within a Ruby script?


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I have a Rakefile with a Rake task that I would normally call from the command line:

rake blog:post Title

I'd like to write a Ruby script that calls that Rake task multiple times, but the only solution I see is shelling out using `` (backticks) or system.

What's the right way to do this?


所有的回答
  • Translate

    from timocracy.com:

    require 'rake'
    require 'rake/rdoctask'
    require 'rake/testtask'
    require 'tasks/rails'
    
    def capture_stdout
      s = StringIO.new
      oldstdout = $stdout
      $stdout = s
      yield
      s.string
    ensure
      $stdout = oldstdout
    end
    
    Rake.application.rake_require '../../lib/tasks/metric_fetcher'
    results = capture_stdout {Rake.application['metric_fetcher'].invoke}
    

  • Translate

    This works with Rake version 10.0.3:

    require 'rake'
    app = Rake.application
    app.init
    # do this as many times as needed
    app.add_import 'some/other/file.rake'
    # this loads the Rakefile and other imports
    app.load_rakefile
    
    app['sometask'].invoke
    

    As knut said, use reenable if you want to invoke multiple times.


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    You can use invoke and reenable to execute the task a second time.

    Your example call rake blog:post Title seems to have a parameter. This parameter can be used as a parameter in invoke:

    Example:

    require 'rake'
    task 'mytask', :title do |tsk, args|
      p "called #{tsk} (#{args[:title]})"
    end
    
    
    
    Rake.application['mytask'].invoke('one')
    Rake.application['mytask'].reenable
    Rake.application['mytask'].invoke('two')
    

    Please replace mytask with blog:post and instead the task definition you can require your rakefile.

    This solution will write the result to stdout - but you did not mention, that you want to suppress output.


    Interesting experiment:

    You can call the reenable also inside the task definition. This allows a task to reenable himself.

    Example:

    require 'rake'
    task 'mytask', :title do |tsk, args|
      p "called #{tsk} (#{args[:title]})"
      tsk.reenable  #<-- HERE
    end
    
    Rake.application['mytask'].invoke('one')
    Rake.application['mytask'].invoke('two')
    

    The result (tested with rake 10.4.2):

    "called mytask (one)"
    "called mytask (two)"
    

  • Translate

    In a script with Rails loaded (e.g. rails runner script.rb)

    def rake(*tasks)
      tasks.each do |task|
        Rake.application[task].tap(&:invoke).tap(&:reenable)
      end
    end
    
    rake('db:migrate', 'cache:clear', 'cache:warmup')