module WEBrick::AccessLog

AccessLog provides logging to various files in various formats.

Multiple logs may be written to at the same time:

access_log = [
  [$stderr, WEBrick::AccessLog::COMMON_LOG_FORMAT],
  [$stderr, WEBrick::AccessLog::REFERER_LOG_FORMAT],
]

server = WEBrick::HTTPServer.new :AccessLog => access_log

Custom log formats may be defined. WEBrick::AccessLog provides a subset of the formatting from Apache’s mod_log_config httpd.apache.org/docs/mod/mod_log_config.html#formats. See AccessLog::setup_params for a list of supported options

Constants

AGENT_LOG_FORMAT: User-Agent Log Format
CLF: Short alias for Common Log Format
CLF_TIME_FORMAT: The Common Log Format’s time format
COMBINED_LOG_FORMAT: Combined Log Format
COMMON_LOG_FORMAT: Common Log Format
REFERER_LOG_FORMAT: Referer Log Format

Public Instance Methods

escape (data)

Source

# File vendor/bundle/ruby/3.4.0/gems/webrick-1.9.1/lib/webrick/accesslog.rb, line 151
def escape(data)
  data = data.gsub(/[[:cntrl:]\\]+/) {$&.dump[1...-1]}
  data.untaint if RUBY_VERSION < '2.7'
  data
end

Escapes control characters in data

format (format_string, params)

Source

# File vendor/bundle/ruby/3.4.0/gems/webrick-1.9.1/lib/webrick/accesslog.rb, line 123
def format(format_string, params)
  format_string.gsub(/\%(?:\{(.*?)\})?>?([a-zA-Z%])/){
     param, spec = $1, $2
     case spec[0]
     when ?e, ?i, ?n, ?o
       raise AccessLogError,
         "parameter is required for \"#{spec}\"" unless param
       (param = params[spec][param]) ? escape(param) : "-"
     when ?t
       params[spec].strftime(param || CLF_TIME_FORMAT)
     when ?p
       case param
       when 'remote'
         escape(params["i"].peeraddr[1].to_s)
       else
         escape(params["p"].to_s)
       end
     when ?%
       "%"
     else
       escape(params[spec].to_s)
     end
  }
end

Formats params according to format_string which is described in setup_params.

setup_params (config, req, res)

Source

# File vendor/bundle/ruby/3.4.0/gems/webrick-1.9.1/lib/webrick/accesslog.rb, line 95
def setup_params(config, req, res)
  params = Hash.new("")
  params["a"] = req.peeraddr[3]
  params["b"] = res.sent_size
  params["e"] = ENV
  params["f"] = res.filename || ""
  params["h"] = req.peeraddr[2]
  params["i"] = req
  params["l"] = "-"
  params["m"] = req.request_method
  params["n"] = req.attributes
  params["o"] = res
  params["p"] = req.port
  params["q"] = req.query_string
  params["r"] = req.request_line.sub(/\x0d?\x0a\z/o, '')
  params["s"] = res.status       # won't support "%>s"
  params["t"] = req.request_time
  params["T"] = Time.now - req.request_time
  params["u"] = req.user || "-"
  params["U"] = req.unparsed_uri
  params["v"] = config[:ServerName]
  params
end

This format specification is a subset of mod_log_config of Apache:

%a: Remote IP address
%b: Total response size
%e{variable}: Given variable in ENV
%f: Response filename
%h: Remote host name
%{header}i: Given request header
%l: Remote logname, always “-”
%m: Request method
%{attr}n: Given request attribute from req.attributes
%{header}o: Given response header
%p: Server’s request port
%{format}p: The canonical port of the server serving the request or the actual port or the client’s actual port. Valid formats are canonical, local or remote.
%q: Request query string
%r: First line of the request
%s: Request status
%t: Time the request was received
%T: Time taken to process the request
%u: Remote user from auth
%U: Unparsed URI
%%: Literal %