Capistrano-Deploy-Tagger creates and updates certain tags in Git each time you perform a deploy. The first tag defaults to 'inproduction' and is always updated to refer to the revision that was just deployed. The second tag is a timestamp applied to every revision that is deployed to production.
Gemfile gem 'capistrano-deploy-tagger', '~> 2.3.4'
install gem install capistrano-deploy-tagger