ChefEmailOnFailure

#I spent many hours today trying to grok Handlers in Chef, and get a functional email handler in place.
#This is a brain dump of my configuration in the hopes that others find it useful (and to remind myself).

#cd to your repo's cookbooks directory, download the chef_handler cookbook, and un-tarzip
knife cookbook site download chef_handler
tar -xvzf chef_handler.tgz

#create a send_email.rb handler in your default chef_hander handler directory with the below results
#replace EMAILADDRESS, DOMAIN, EMAILSERVER with values for your environment
vi ~/repo/cookbooks/chef_handler/files/default/handlers/send_email.rb
#############################################################################
require 'net/smtp'

module MyEmail
  class SendEmail < Chef::Handler
    def report
      message = "From: Chef <[email protected]>\n"
      message << "To: Me <[email protected]>\n"
      message << "Subject: Chef run failed\n"
      message << "Date: #{Time.now.rfc2822}\n\n"
      message << "Chef run failed on #{node.name}\n\n"
      message << "------------------------------------------------------\n"
      message << "                      EXCEPTION                       \n"
      message << "------------------------------------------------------\n"
      message << "#{run_status.formatted_exception}\n"
      message << "------------------------------------------------------\n"
      message << "                     STACK TRACE                      \n"
      message << "------------------------------------------------------\n"
      # Join the backtrace lines. Coerce to an array just in case.
      message << Array(backtrace).join("\n")

      Net::SMTP.start('EMAILSERVER.DOMAIN.com', 25) do |smtp|
        smtp.send_message message, '[email protected]', '[email protected]'
      end
    end
  end
end
#############################################################################

#in the cookbook in which you'd like to include notifications on failure, modify your default.rb recipe
#to include chef_handler, as well as a definition for your new notification using chef_handler
vi ~/repo/cookbooks/mycookbook/recipes/default.rb
#############################################################################
include_recipe 'chef_handler'

chef_handler "MyEmail::SendEmail" do
   source "#{node['chef_handler']['handler_path']}\\send_email.rb"
   action :nothing
   supports :exception=>true
end.run_action(:enable)
#############################################################################

#upload your cookbooks to Chef server
knife cookbook upload chef_handler
knife cookbook upload mycookbook

#if you'd like to fail your cookbook push for testing purposes, you can use thus Ruby block from the Chef documentation to do that
vi ~/repo/cookbooks/mycookbook/recipes/default.rb
#############################################################################
ruby_block 'fail the run' do
  block do
    fail 'deliberately fail the run'
  end
end
#############################################################################