Capistrano::Stopwatch

Capistrano::Stopwatch is a gem to measure the execution time of each Capistrano tasks. Capistrano::Stopwatch requires Capistrano v3 or above.

Add this line to your application's Gemfile:

gem 'capistrano-stopwatch'

And then execute:

$ bundle

Or install it yourself as:

$ gem install capistrano-stopwatch

Takes four simple steps to run Capistrano::Stopwatch on your environment.

# Capfile
require 'capistrano-stopwatch'

Right now, you need to manually specify tasks you want to measure execution time. All you need to do is just call measure_duration method in config/deploy.rb and hand it name of tasks.

# config/deploy.rb
['deploy:starting', 'deploy:updating'].each do |n|
  measure_duration(n)
end

Specify when to run stopwatch:finish task and execute finish_stopwatch lambda function. Usually, it is safe to run stopwatch:finish after the very last task in your Capistrano deploy flow.

# config/deploy.rb
after 'test:stop', 'stopwatch:finish'

Override finish_stopwatch and specify how to handle the output, which is a hash of task name and execution time. By default, finish_stopwatch simply prints the output to stdout.

# config/deploy.rb
set :finish_stopwatch, lambda { |durations|
  File.open("durations.json", "w") {|f| f.puts(durations.to_json) }
}

# Capfile
require 'capistrano-stopwatch'

# config/deploy.rb
require 'json'

set :finish_stopwatch, lambda { |durations|
  File.open("durations.json", "w") {|f| f.puts(durations.to_json) }
  puts durations
}

namespace :example do
  task :first do
    run_locally do
      info 'Running first task'
      sleep 1
    end
  end

  task :second do
    run_locally do
      info 'Running second task'
      sleep 2
    end
  end

  task :third do
    run_locally do
      info 'Running third task'
      sleep 3
    end
  end
end

['example:first', 'example:second', 'example:third'].each do |task|
  measure_duration(task)
end

after 'example:third', 'stopwatch:finish'

$ bundle ex cap development example:first example:second example:third
00:00 example:first
      Running first task
00:01 example:second
      Running second task
00:03 example:third
      Running third task
00:06 stopwatch:finish
      Finishing stopwatch
{"example:first"=>1.001629, "example:second"=>2.002746, "example:third"=>3.004129}

$ cat durations.json
{"example:first":1.001246,"example:second":2.004474,"example:third":3.00379}

AWS CloudWatch Logs Insights might be another good option to gether information about task execution time, even though you need to set how to parse Capistrano logs.

Bug reports and pull requests are welcome on GitHub at https://github.com/shuheiktgw/capistrano-stopwatch. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the Capistrano::Stopwatch project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.