What a capistrano-notifier notifier could look like

statsd.rb

require 'capistrano/notifier/base'
require 'statsd-instrument'

class Capistrano::Notifier::StatsD
  include Capistrano::Notifier::Base
  name :statsd
  description 'Notifies StatsD of a deploy'

  # The base module takes this method and loads it in as a task of the
  # current capistrano instance
  def notify
    # 'get' here could be a shortcut to capistrano's get (or is it fetch?) that prepends notify_#{name},
    # then in your deploy.rb you do `set :notify_statsd_host, '10.0.0.1'`
    StatsD.host = get :host # get :notify_statsd_host
    # ... and so on, or read from config/stats.yml ...
    StastD.increment(get :key) # get :notify_statsd_key => #{application}.deploy.#{stage}
  end

  # do whatever you want in the rest of the class
end
# produces =>
desc 'Notifies StatsD of a deploy'
namespace :deploy do
  namespace :notify do
    task :statsd do
      # ... eval notify ...
    end
  end
end
after 'deploy', 'deploy:notify:statsd'