How do I run a rake task from Capistrano?

Question

I already have a deploy.rb that can deploy my app on my production server.

My app contains a custom rake task (a .rake file in the lib/tasks directory).

I\

Answer 1

Use the capistrano-rake gem

Just install the gem without messing with custom capistrano recipes and execute desired rake tasks on remote servers like this:

cap production invoke:rake TASK=my:rake_task

Full Disclosure: I wrote it

Answer 2

namespace :rake_task do
  task :invoke do
    if ENV['COMMAND'].to_s.strip == ''
      puts "USAGE: cap rake_task:invoke COMMAND='db:migrate'" 
    else
      run "cd #{current_path} && RAILS_ENV=production rake #{ENV['COMMAND']}"
    end
  end                           
end 

Answer 3

Most of it is from above answer with a minor enhancement to run any rake task from capistrano

Run any rake task from capistrano

$ cap rake -s rake_task=$rake_task

# Capfile     
task :rake do
  rake = fetch(:rake, 'rake')
  rails_env = fetch(:rails_env, 'production')

  run "cd '#{current_path}' && #{rake} #{rake_task} RAILS_ENV=#{rails_env}"
end

Answer 4

So I have been working on this. it seams to work well. However you need a formater to really take advantage of the code.

If you don't want to use a formatter just set the log level to to debug mode. These semas to h

SSHKit.config.output_verbosity = Logger::DEBUG

Cap Stuff

namespace :invoke do
  desc 'Run a bash task on a remote server. cap environment invoke:bash[\'ls -la\'] '
  task :bash, :execute do |_task, args|
    on roles(:app), in: :sequence do
      SSHKit.config.format = :supersimple
      execute args[:execute]
    end
  end

  desc 'Run a rake task on a remote server. cap environment invoke:rake[\'db:migrate\'] '
  task :rake, :task do |_task, args|
    on primary :app do
      within current_path do
        with rails_env: fetch(:rails_env) do
          SSHKit.config.format = :supersimple
          rake args[:task]
        end
      end
    end
  end
end

This is the formatter I built to work with the code above. It is based off the :textsimple built into the sshkit but it is not a bad way to invoke custom tasks. Oh this many not works with the newest version of sshkit gem. I know it works with 1.7.1. I say this because the master branch has changed the SSHKit::Command methods that are available.

module SSHKit
  module Formatter
    class SuperSimple < SSHKit::Formatter::Abstract
      def write(obj)
        case obj
        when SSHKit::Command    then write_command(obj)
        when SSHKit::LogMessage then write_log_message(obj)
        end
      end
      alias :<< :write

      private

      def write_command(command)
        unless command.started? && SSHKit.config.output_verbosity == Logger::DEBUG
          original_output << "Running #{String(command)} #{command.host.user ? "as #{command.host.user}@" : "on "}#{command.host}\n"
          if SSHKit.config.output_verbosity == Logger::DEBUG
            original_output << "Command: #{command.to_command}" + "\n"
          end
        end

        unless command.stdout.empty?
          command.stdout.lines.each do |line|
            original_output << line
            original_output << "\n" unless line[-1] == "\n"
          end
        end

        unless command.stderr.empty?
          command.stderr.lines.each do |line|
            original_output << line
            original_output << "\n" unless line[-1] == "\n"
          end
        end

      end

      def write_log_message(log_message)
        original_output << log_message.to_s + "\n"
      end
    end
  end
end

Answer 5

Here's what I put in my deploy.rb to simplify running rake tasks. It's a simple wrapper around capistrano's run() method.

def rake(cmd, options={}, &block)
  command = "cd #{current_release} && /usr/bin/env bundle exec rake #{cmd} RAILS_ENV=#{rails_env}"
  run(command, options, &block)
end

Then I just run any rake task like so:

rake 'app:compile:jammit'

Answer 6

I personally use in production a helper method like this:

def run_rake(task, options={}, &block)
  command = "cd #{latest_release} && /usr/bin/env bundle exec rake #{task}"
  run(command, options, &block)
end

That allows to run rake task similar to using the run (command) method.

---

NOTE: It is similar to what Duke proposed, but I:

• use latest_release instead of current_release - from my experience it is more what you expect when running a rake command;
• follow the naming convention of Rake and Capistrano (instead of: cmd -> task and rake -> run_rake)
• don't set RAILS_ENV=#{rails_env} because the right place to set it is the default_run_options variable. E.g default_run_options[:env] = {'RAILS_ENV' => 'production'} # -> DRY!