Example of Chef hanfler for sending run fails to Pushover (notifications to iPhone and Android) https://pushover.net/

pushover_handler.rb

# cookbook/files/default/pushover_handler.rb

require "net/https"

module MyOrg
  class PushOver < Chef::Handler

    def initialize(config={})
      @config = config
    end

    def report
      return unless run_status.failed?
      return if @config.empty?

      # The Node is available as +node+
      title = "Failed node #{node.name}"
      # +run_status+ is a value object with all of the run status data
      message = run_status.formatted_exception

      url = URI.parse("https://api.pushover.net/1/messages.json")
      req = Net::HTTP::Post.new(url.path)
      req.set_form_data({
        :token => @config[:app_token],
        :user  => @config[:user_key],
        :title => title,
        :message => message,
      })
      https = Net::HTTP.new(url.host, url.port)
      https.use_ssl = true
      # It should be OpenSSL::SSL::VERIFY_PEER, but it wasn't working
      https.verify_mode = OpenSSL::SSL::VERIFY_NONE
      https.start {|http| http.request(req) }

      Chef::Log.info("Myorg::PushOver sending Pushover notification")
    end
  end
end

reports.rb

# cookbook/recipes/reports.rb

pushover_report_path = "#{node['chef_handler']['handler_path']}/pushover_handler.rb"
cookbook_file pushover_report_path

include_recipe "chef_handler::default"

chef_handler 'MyOrg::PushOver' do
  source pushover_report_path
  arguments :app_token => node['myorg']['pushover']['app_token'],
            :user_key => node['myorg']['pushover']['user_key']
  action :enable
end

run_list.json

{
  "run_list": ["recipe[myorg::reports]", "recipe[myorg::foo]"]
}