Class: CapistranoUnicorn::CapistranoIntegration

Inherits:
Object
  • Object
show all
Defined in:
lib/capistrano-unicorn/capistrano_integration.rb

Constant Summary collapse

TASKS = 
[
  'unicorn:start',
  'unicorn:stop',
  'unicorn:restart',
  'unicorn:reload', 
  'unicorn:shutdown',
  'unicorn:add_worker',
  'unicorn:remove_worker'
]

Class Method Summary collapse

Class Method Details

.load_into(capistrano_config) ⇒ Object 



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# File 'lib/capistrano-unicorn/capistrano_integration.rb', line 16

def self.load_into(capistrano_config)
  capistrano_config.load do
    before(CapistranoIntegration::TASKS) do
      _cset(:app_env)        { (fetch(:rails_env) rescue 'production') }
      _cset(:unicorn_pid)    { "#{fetch(:current_path)}/tmp/pids/unicorn.pid" }
      _cset(:unicorn_env)    { fetch(:app_env) }
      _cset(:unicorn_bin)    { "unicorn" }
      _cset(:unicorn_bundle) { fetch(:bundle_cmd) rescue 'bundle' }
    end

    # Check if a remote process exists using its pid file
    #
    def remote_process_exists?(pid_file)
      "[ -e #{pid_file} ] && kill -0 `cat #{pid_file}` > /dev/null 2>&1"
    end

    # Stale Unicorn process pid file
    #
    def old_unicorn_pid
      "#{unicorn_pid}.oldbin"
    end

    # Command to check if Unicorn is running
    #
    def unicorn_is_running?
      remote_process_exists?(unicorn_pid)
    end

    # Command to check if stale Unicorn is running
    #
    def old_unicorn_is_running?
      remote_process_exists?(old_unicorn_pid)
    end

    # Get unicorn master process PID (using the shell)
    #
    def get_unicorn_pid(pid_file=unicorn_pid)
      "`cat #{pid_file}`"
    end

    # Get unicorn master (old) process PID
    #
    def get_old_unicorn_pid
      get_unicorn_pid(old_unicorn_pid)
    end

    # Send a signal to a unicorn master processes
    #
    def unicorn_send_signal(signal, pid=get_unicorn_pid)
      "#{try_sudo} kill -s #{signal} #{pid}"
    end

    # Kill Unicorns in multiple ways O_O
    #
    def kill_unicorn(signal)
      script = <<-END
        if #{unicorn_is_running?}; then
          echo "Stopping Unicorn...";
          #{unicorn_send_signal(signal)};
        else
          echo "Unicorn is not running.";
        fi;
      END

      script
    end

    # Start the Unicorn server
    #
    def start_unicorn
      primary_config_path = "#{current_path}/config/unicorn.rb"
      secondary_config_path = "#{current_path}/config/unicorn/#{unicorn_env}.rb"

      script = <<-END
        if [ -e #{primary_config_path} ]; then
          UNICORN_CONFIG_PATH=#{primary_config_path};
        else
          if [ -e #{secondary_config_path} ]; then
            UNICORN_CONFIG_PATH=#{secondary_config_path};
          else
            echo "Config file for \"#{unicorn_env}\" environment was not found at either \"#{primary_config_path}\" or \"#{secondary_config_path}\"";
            exit 1;
          fi;
        fi;

        if [ -e #{unicorn_pid} ]; then
          if kill -0 `cat #{unicorn_pid}` > /dev/null 2>&1; then
            echo "Unicorn is already running!";
            exit 0;
          fi;

          rm #{unicorn_pid};
        fi;

        echo "Starting Unicorn...";
        cd #{current_path} && BUNDLE_GEMFILE=#{current_path}/Gemfile #{unicorn_bundle} exec #{unicorn_bin} -c $UNICORN_CONFIG_PATH -E #{app_env} -D;
      END

      script
    end

    #
    # Unicorn cap tasks
    #
    namespace :unicorn do
      desc 'Start Unicorn master process'
      task :start, :roles => :app, :except => {:no_release => true} do
        run start_unicorn
      end

      desc 'Stop Unicorn'
      task :stop, :roles => :app, :except => {:no_release => true} do
        run kill_unicorn('QUIT')
      end

      desc 'Immediately shutdown Unicorn'
      task :shutdown, :roles => :app, :except => {:no_release => true} do
        run kill_unicorn('TERM')
      end

      desc 'Restart Unicorn'
      task :restart, :roles => :app, :except => {:no_release => true} do
        run <<-END
          if #{unicorn_is_running?}; then
            echo "Restarting Unicorn...";
            #{unicorn_send_signal('USR2')};
          else
            #{start_unicorn}
          fi;

          sleep 2; # in order to wait for the (old) pidfile to show up

          if #{old_unicorn_is_running?}; then
            #{unicorn_send_signal('QUIT', get_old_unicorn_pid)};
          fi;
        END
      end

      desc 'Reload Unicorn'
      task :reload, :roles => :app, :except => {:no_release => true} do
        run <<-END
          if #{unicorn_is_running?}; then
            echo "Reloading Unicorn...";
            #{unicorn_send_signal('HUP')};
          else
            #{start_unicorn}
          fi;
        END
      end

      desc 'Add a new worker'
      task :add_worker, :roles => :app, :except => {:no_release => true} do
        run <<-END
          if #{unicorn_is_running?}; then
            echo "Adding a new Unicorn worker...";
            #{unicorn_send_signal('TTIN')};
          else
            echo "Unicorn is not running.";
          fi;
        END
      end

      desc 'Remove amount of workers'
      task :remove_worker, :roles => :app, :except => {:no_release => true} do
        run <<-END
          if #{unicorn_is_running?}; then
            echo "Removing a Unicorn worker...";
            #{unicorn_send_signal('TTOU')};
          else
            echo "Unicorn is not running.";
          fi;
        END
      end
    end
  end
end