class LtsvLoggerFormatter

A logger formatter for logging in ltsv format.

This is a sub class of ::Logger::Formatter. So you can use ::Logger's formatter as follows.

logger = ::Logger.new(STDOUT)
logger.formatter = ::LtsvLoggerFormatter.new
logger.info(key: 'value') # => level:INFO time:2017-03-19T01:47:50.280705 key:value

Constants

VERSION

Attributes

progname_key[RW]

severity_key[RW]

time_key[RW]

Public Class Methods

new(datetime_format: '%Y-%m-%dT%H:%M:%S.%6N', severity_key: :level, time_key: :time, progname_key: :progname, filter: nil) click to toggle source

Initialize formatter.

@param [String] datetime_format Optional, datetime format string. Default is '%Y-%m-%dT%H:%M:%S.%6N'. @param [Symbol] severity_key Optional, key for severity. Default is :level. @param [Symbol] time_key Optional, key for time. Default is :time. @param [Symbol] progname_key Optional, key for progname. Default is :progname. @param [Object] filter Optional, object which responds to filter, e.g. ActionDispatch::Http::ParameterFilter.

This object used to filter parameter in hash such as 'password'.

Calls superclass method

# File lib/ltsv_logger_formatter.rb, line 25
def initialize(datetime_format: '%Y-%m-%dT%H:%M:%S.%6N',
               severity_key: :level, time_key: :time, progname_key: :progname, filter: nil)
  super()
  self.datetime_format = datetime_format
  @severity_key = severity_key
  @time_key = time_key
  @progname_key = progname_key
  @filter = filter
end

Public Instance Methods

call(severity, time, progname, data) click to toggle source

Return formatted string using arguments.

This method is expected to call by ::Logger

@param [String] severity @param [Time] time @param [String] progname @param [Hash, Exception, Object] data Data for logging,

If data is Exception, then #message, #class and #backtrace is logged,
or else if data can be respond to #to_hash, then #to_hash result is logged,
or else #to_s result is logged with :message key.
Hash, String, Exception or Object respond_to :to_hash can be used.

# File lib/ltsv_logger_formatter.rb, line 47
def call(severity, time, progname, data)
  log_data = { @severity_key => severity, @time_key => format_datetime(time) }
  if progname
    log_data[@progname_key] = progname
  end
  log_data.merge!(format_data(data))
  ::LTSV.dump(log_data) + "\n"
end

Private Instance Methods

format_data(data) click to toggle source

# File lib/ltsv_logger_formatter.rb, line 58
def format_data(data)
  if data.is_a? Exception
    return { message: data.message, class: data.class, backtrace: Array(data.backtrace).join('\n') }
  end
  return { message: data.to_s } unless data.respond_to?(:to_hash)

  @filter ? @filter.filter(data.to_hash) : data.to_hash
end