How to pass arguments to Capistrano 3 tasks in deploy.rb

Question

Here is an tutorial how to pass parameters to an capistrano 3 task.

namespace :task do
  desc 'Execute the specific cmd task'
  task :invoke, :command do |task, args|
    on roles(:app) do
      execute :cmd, args[:command]
    end
  end
end

Can executed with:

$ cap staging "task:invoke[arg]"

How can i use this in my deploy.rb? The following does not work.

before :started, "task:invoke[arg]"

Answer 1

Not sure about before/after, but with Capistrano 3 you can always use the rake syntax and call task from within another task:

Rake::Task["mynamespace:mytask"].invoke(arg)

Answer 2

You can use invoke method:

before :started, :second_param do
  invoke 'task:invoke', 'arg'
end

Also one thing which might be helpful, capistrano and rake allowing to execute task only first time, this might be common issue for task with parameters, cause you may reuse it with different value. To allow doing it you need to re-enable the task:

namespace :task do
  desc 'Execute the specific cmd task'
  task :invoke, :command do |task, args|
    on roles(:app) do
      execute :cmd, args[:command]
      task.reenable                # <--------- this how to re-enable it
    end
  end
end