Rails tagged logger with user id

tag_logger.rb

#
# This Tag logger adds users that to the request example:
#   2017-02-08 15:07:13.227 [fyi]  [ce3cfbef-792d-4606-b8d4-927cd526fe7f] Completed 200 OK in 4355ms

module WardenTaggedLogger
  def self.extract_user_id_from_request(req)
    session_key = Rails.application.config.session_options[:key]
    session_data = req.cookie_jar.encrypted[session_key]
    if session_data.present? && session_data.has_key?('warden.user.user.key')
      session_data['warden.user.user.key'][0][0]
    else
      "guest"
    end
  end
end

Rails.configuration.log_tags = [
  ->(req){
    WardenTaggedLogger.extract_user_id_from_request(req)
  }
]