README.md

Most instructions for using Capistrano tell you how to make it restart Phusion Passenger by 'touch'ing the restart.txt file, but this doesn't immediately restart the app - instead the first person to try to use the application will cause it to be restarted, so they will see a delay of at least a few seconds.

This shows how to add a post-deploy task to 'ping' the server, to cause it to restart immediately.

Then add a deploy:ping task to config/deploy.rb and set it to run automatically after deploy:restart. Alternatively you could put it into the deploy:restart task directly.

TODO: Test the response HTTP header of the ping, that it is a 200, and not some other error response (404/500).

deploy.rb

# config/deploy.rb
set :application, 'sampleapp'

#What is an accessible route to hit on the site?
#Note: I have nginx+passenger listening to :8080, our environment has a different web server entrypoint
#Also, our apps get deployed to a sub-uri, with the application_name as its URI 
set :ping_url, "http://localhost:8080/#{fetch(:application)}"

# This is the standard Phusion Passenger restart code. You will probably already
# have something like this (if you have already got Capistrano set up).
namespace :deploy do

  desc 'Restart application'
  task :restart do
    on roles(:app), in: :sequence, wait: 5 do
      # Your restart mechanism here, for example:
      execute "mkdir -p #{release_path.join('tmp')}"
      execute :touch, release_path.join('tmp/restart.txt')
    end
  end

  after :publishing, :restart

  

  desc 'Warm up the application by pinging it, so enduser wont have to wait'
  task :ping do
    on roles(:app), in: :sequence, wait: 5 do
      execute "curl -s -D - #{fetch(:ping_url)} -o /dev/null"
    end
  end

  after :restart, :ping


  after :restart, :clear_cache do
    on roles(:web), in: :groups, limit: 3, wait: 10 do
      # Here we can do anything such as:
      # within release_path do
      #   execute :rake, 'cache:clear'
      # end
    end
  end

end

routes.rb

# config/routes.rb

SampleApp::Application.routes.draw do
  root to: 'application#index'
end