Capistrano: How to find out which version of your application is currently live

When deploying, Capistrano puts a REVISION file into your application's release directory. It contains the hash of the commit which was deployed.

If you want to know the currently deployed release, simply SSH to a server and view that file.

$ cat /var/www/my-project/current/REVISION
cf8734ece3938fc67262ad5e0d4336f820689307

Capistrano task

When your application is deployed to multiple servers, you probably want to see a result for all of them.
Here is a Capistrano task that checks all servers with the :app role.

namespace :app do

  desc 'Show deployed revision'
  task :revision do
    on roles :app do |host|
      within current_path do
        info "#{host}: #{capture :cat, 'REVISION'}"
      end
    end
  end
  
end

Output looks like this:

$ cap production app:revision
00:00 deploy:revision
      app01.example.com: cf8734ece3938fc67262ad5e0d4336f820689307
      app02.example.com: cf8734ece3938fc67262ad5e0d4336f820689307
      app03.example.com: cf8734ece3938fc67262ad5e0d4336f820689307

Capistrano 2 (legacy)

namespace :app do

  desc 'Show deployed revision'
  task :revision, roles: :app do
    run "cat #{current_path}/REVISION"
  end

end

Further resources

Note that Capistrano also logs each deployment. We have a separate card on finding out user/branch/commit/timestamp for past deployments.

You can also tag deploys, so you can see deployed commits in the git log.