deploy.rb

require File.join(File.dirname(__FILE__), 'deploy/nginx')
require File.join(File.dirname(__FILE__), 'deploy/log')

default_run_options[:pty] = true
set :ssh_options, { :forward_agent => true }

set :application, "appname"
set :repository,  "git@giturl"

set :scm, :git
set :user, "deploy"
set :deploy_to, "/var/applications/appname"
set :rails_env, "production"
set :branch, "master"

server "appname.com", :web, :app, :db, :primary => true

namespace :deploy do
  desc "Deploy the MFer"
  task :default do
    update
    restart
    cleanup
  end

  desc "Setup a GitHub-style deployment."
  task :setup, :except => { :no_release => true } do
    run "git clone #{repository} #{current_path}"
    update
    run "mkdir -p #{current_path}/tmp/sockets && mkdir -p #{current_path}/tmp/pids"
    db.setup
    migrate
    db.seed
    start
    cleanup
    nginx.start
  end
  
  desc "Update the deployed code."
  task :update_code, :except => { :no_release => true } do
    #run "cd #{current_path}; git fetch origin; git reset --hard #{branch}"
    run "cd #{current_path}; git reset --hard; git pull origin master"
  end
  
  desc "Deploy and run migrations"
  task :migrations, :except => { :no_release => true } do
    update
    migrate
    restart
    cleanup
  end
  
  desc "Run pending migrations on already deployed code"
  task :migrate, :only => {:primary => true}, :except => { :no_release => true } do
    run "cd #{current_path}; RAILS_ENV=#{rails_env} bundle exec rake db:migrate"
  end   
  
  task :symlink, :roles => :app, :except => { :no_release => true } do
    #nothing yet - only exists to wipe out symlink task from super
  end
  
  namespace :db do 
      
    desc "Seed the database on already deployed code"
    task :seed, :only => {:primary => true}, :except => { :no_release => true } do
      run "cd #{current_path}; RAILS_ENV=#{rails_env} bundle exec rake db:seed"
    end     
  
    desc "Setup application schema"
    task :setup do
      run "cd #{current_path}; RAILS_ENV=#{rails_env} bundle exec rake db:create"  
    end
    
    desc "Wipe tables then rerun all migrations and seed database"
    task :remigrate, :only => {:primary => true}, :except => { :no_release => true } do
      run "cd #{current_path}; RAILS_ENV=#{rails_env} bundle exec rake db:remigrate"
    end    
  end
  
  namespace :rollback do
    desc "Rollback"
    task :default, :except => { :no_release => true } do
      code
    end
    
    desc "Rollback a single commit."
    task :code, :except => { :no_release => true } do
      set :branch, "HEAD^"
      default
    end
  end
  
  task :cleanup, :roles => :app, :except => { :no_release => true } do
    # nothing yet
  end    

  # override default tasks to make capistrano happy
  desc "Start unicorn"
  task :start, :roles => :app do
    run "cd #{current_path} && bundle exec unicorn -c #{current_path}/config/unicorn.rb -E #{rails_env} -D"
  end

  desc "Kick unicorn"
  task :restart, :roles => :app do
    run "kill -USR2 `cat #{current_path}/tmp/pids/unicorn.pid`"
  end

  desc "Kill a unicorn"
  task :stop, :roles => :app do
    run "kill -QUIT `cat #{current_path}/tmp/pids/unicorn.pid`"
  end
end

namespace :restore do
  task :db, :roles => :db do
    # from http://www.thegeekstuff.com/2009/01/how-to-backup-and-restore-postgres-database-using-pg_dump-and-psql/
    # 
    # psql -U {user-name} -d {desintation_db}-f {dumpfilename.sql}
  end
end

namespace :backup do
  desc "Backup the database"
  task :db, :roles => :db do
    run "mkdir -p #{current_path}/backups"
    run "cd #{current_path}; pg_dump -U #{user} #{application}_production -f backups/#{Time.now.utc.strftime('%Y%m%d%H%M%S')}.sql"
  end

  desc "Backup the database and download the script"
  task :download, :roles => :app do
    db
    timestamp = Time.now.utc.strftime('%Y%m%d%H%M%S') 
    run "mkdir -p backups"
    run "cd #{current_path}; tar -cvzpf #{timestamp}_backup.tar.gz backups"
    get "#{current_path}/#{timestamp}_backup.tar.gz", "#{timestamp}_backup.tar.gz"
  end
end

namespace :assets do
  task :precompile, :roles => :web do
    run "cd #{current_path}; RAILS_ENV=#{rails_env} bundle exec rake assets:precompile"
  end
  
  task :clean, :roles => :web do
    run "cd #{current_path}; RAILS_ENV=#{rails_env} bundle exec rake assets:clean"
  end
end

namespace :bundler do
  task :bundle_new_release, :roles => :app do
    run "cd #{current_path} && bundle install --deployment --quiet --without development test cucumber"
  end
end
  
after 'deploy:update_code', 'bundler:bundle_new_release'
after 'deploy:update_code', 'assets:precompile'

log.rb

Capistrano::Configuration.instance.load do
  namespace :log do
    desc "Tail all application log files"
    task :tail, :roles => :app do
      run "tail -f #{current_path}/log/*.log" do |channel, stream, data|
        puts "#{channel[:host]}: #{data}"
        break if stream == :err
      end
    end
  end
end

nginx.rb

Capistrano::Configuration.instance.load do
  namespace :nginx do
    desc "Restart nginx"
    task :restart, :roles => :app , :except => { :no_release => true } do
      sudo "/etc/init.d/nginx restart"
    end
    
    desc "Stop nginx"
    task :stop, :roles => :app , :except => { :no_release => true } do
      sudo "/etc/init.d/nginx stop"
    end
    
    desc "Start nginx"
    task :start, :roles => :app , :except => { :no_release => true } do
      sudo "/etc/init.d/nginx start"
    end

    desc "Show nginx status"
    task :status, :roles => :app , :except => { :no_release => true } do
      sudo "/etc/init.d/nginx status"
    end
  end
end