basic-rails/app/controllers/welcome_controller.rb

class WelcomeController < ApplicationController
  def index
    logger.measure_error "Took too long to complete", min_duration: 3000 do
      logger.debug("Debugging information to aid with problem determination")
      logger.info("Informational message such as request received\nline 2\nline3")
      logger.warn("Warn about something in the system")
      logger.error("An error occurred during processing")
      logger.fatal("Oh no something really bad happened")

      logger.measure_info "Called external interface" do
        sleep 0.1 # Code to call external service ...
      end

      SemanticLogger.tagged(user: "Jack", zip_code: 12345) do
        # All log entries in this block will include the above named tags
        logger.debug("Hello World")
      end

      # raise "exception"
    end
  end
end