logger_customizations.rb

# config/initializers/logger_customizations.rb
# Production-only monkeypatches to make our logs awesome

# Monkeypatch 1
# Don't log common poller-style requests, they are just noise
class CustomLogger < Rails::Rack::Logger
  def initialize(app, opts = {})
    @app = app
    @opts = opts
    @opts[:silenced] ||= []
  end

  def call(env)
    # if env['X-SILENCE-LOGGER'] || @opts[:silenced].include?(env['PATH_INFO'])
    if @opts[:silenced].include?(env['PATH_INFO'])
      Rails.logger.silence do
        @app.call(env)
      end
    else
      super(env)
    end
  end
end

silenced_actions = if ::Rails.env.production?
  ["/notifications/unread_count.json", "/video_counts.json"]
else
  []
end
Rails.configuration.middleware.swap Rails::Rack::Logger, CustomLogger, :silenced => silenced_actions


# Monkeypatch round 2
# * add timestamps + loglevel
# * skip "Rendered partial..." lines
module ActiveSupport
  class BufferedLogger
    def add(severity, message = nil, progname = nil, &block)
      return if @level > severity

      # Skip "Rendered..." messages in production
      if message =~ /^Rendered/ && ::Rails.env.production?
        return
      end

      # Add timestamps + severity
      timestamp = DateTime.now.strftime("%Y-%m-%d %H:%M:%S")
      human_severity = {
        0 => "DEBUG",
        1 => "INFO",
        2 => "WARN",
        3 => "ERROR",
        4 => "FATAL"
      }[severity] || "U"

      message = (message || (block && block.call) || progname).to_s
      if message[0] == ?\n
        buffer << "\n"
        auto_flush
        message = message.strip
      end
      prefix = "[#{timestamp} #{human_severity}] " if ::Rails.env.production?
      message = "#{prefix}#{message}\n" unless message[-1] == ?\n
      buffer << message
      auto_flush
      message
    end
  end
end