rack log format

kernel.rb

module Kernel
  def suppress_warnings
    original_verbosity = $VERBOSE
    $VERBOSE = nil
    result = yield
    $VERBOSE = original_verbosity
    return result
  end
end

rack_commonlogger.rb

module Rack
  class CommonLogger
    Kernel::suppress_warnings do
      # Overriding the original constant
      FORMAT = %{%s - %s [%s] "%s %s%s %s" %d %s %0.4f\n}
    end

    def initialize(app, logger=nil)
      @app = app
      @logger = logger
    end

    def call(env)
      began_at = Time.now
      status, header, body = @app.call(env)
      header = Utils::HeaderHash.new(header)
      log(env, status, header, began_at)
      [status, header, body]
    end

    private
    def log(env, status, header, began_at)
      now = Time.now
      length = extract_content_length(header)

      logger = @logger || env['rack.errors']
      logger.write FORMAT % [
        env['HTTP_X_REAL_IP'] || env['HTTP_X_FORWARDED_FOR'] || env["REMOTE_ADDR"] || "-",
        env["REMOTE_USER"] || "-",
        now.strftime("%d/%m/%Y %H:%M:%S"),
        env["REQUEST_METHOD"],
        env["PATH_INFO"],
        env["QUERY_STRING"].empty? ? "" : "?"+env["QUERY_STRING"],
        env["HTTP_VERSION"],
        status.to_s[0..3],
        length,
        now - began_at ]
    end

    def extract_content_length(headers)
      value = headers['Content-Length'] or return '-'
      value.to_s == '0' ? '-' : value
    end
  end
end