How to Write Capistrano Task for Non Rails

Because capistrano is so powerful, sometimes, we want to use it with other things other than Rails. Here is a quick example.

I want to get a single command line output on my remote host e.g. free -m

  • Install capistrano

      $ vi Gemfile

      source 'https://rubygems.org'
      gem 'capistrano', '~> 2.15'

  $ bundle install

  • Generate capistrano

      $ capify .

  • Create a task

      $ vi config/deploy.rb

      set :application, "my-app-ios"

      set :user, "chawarong.s"
      set :host, "my.example.com"

      role :web, "#{host}"                          # Your HTTP server, Apache/etc
      role :app, "#{host}"

      namespace :monitor do
        task :free do
          output = capture "free -m"
          puts output

        end
      end

  • Run it

      $ cap monitor:free
    * 2014-01-09 15:36:47 executing `monitor:free'
    * executing "free -m"
      servers: ["my.example.com"]
      [my.example.com] executing command
      command finished in 376ms
               total       used       free     shared    buffers     cached
  Mem:          2003       1845        158          0        183        984
  -/+ buffers/cache:        677       1326
  Swap:          507          0        507



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