Class: SemanticLogger::Appender::Graylog

Inherits:
Subscriber show all
Defined in:
lib/semantic_logger/appender/graylog.rb

Overview

Forward log entries to a Graylog server.

Example:

SemanticLogger.add_appender(
  appender: :graylog,
  url:      'udp://localhost:12201'
)

Notes:

  • trace is not supported by Graylog, so trace level logging will appear as debug in Graylog.

In the Graylog Web UI search screen, it is recommended to include the following fields:

`duration`, `level`, `message`, `metric`, `name`, `tags

Constant Summary collapse

LEVEL_MAP =

Map Semantic Logger levels to Graylog levels

{
  fatal: GELF::FATAL,
  error: GELF::ERROR,
  warn:  GELF::WARN,
  info:  GELF::INFO,
  debug: GELF::DEBUG,
  trace: GELF::DEBUG
}

Instance Attribute Summary collapse

Attributes inherited from Subscriber

#application, #formatter, #host

Attributes inherited from Base

#filter, #name

Instance Method Summary collapse

Methods inherited from Subscriber

#close, #default_formatter, #flush, #level

Methods inherited from Base

#fast_tag, #level, #level=, #measure, #payload, #pop_tags, #push_tags, #silence, #tagged, #tags, #with_payload

Constructor Details

#initialize(options = {}, &block) ⇒ Graylog

Create Graylog log appender.

Options:

url: [String]
  Valid URL to post to.
  Log to UDP Example:
    'udp://localhost:12201'
  Log to TCP Example:
    'tcp://localhost:12201'
  Default: 'udp://localhost:12201'

max_size: [String]
  Max udp packet size. Ignored when protocol is :tcp
  Default: "WAN"

level: [:trace | :debug | :info | :warn | :error | :fatal]
  Override the log level for this appender.
  Default: SemanticLogger.default_level

formatter: [Object|Proc]
  An instance of a class that implements #call, or a Proc to be used to format
  the output from this appender
  Default: Use the built-in formatter (See: #call)

filter: [Regexp|Proc]
  RegExp: Only include log messages where the class name matches the supplied.
  regular expression. All other messages will be ignored.
  Proc: Only include log messages where the supplied Proc returns true
        The Proc must return true or false.

host: [String]
  Name of this host to appear in log messages.
  Default: SemanticLogger.host

application: [String]
  Name of this application to appear in log messages.
  Default: SemanticLogger.application

Raises:

  • (ArgumentError) 


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# File 'lib/semantic_logger/appender/graylog.rb', line 71

def initialize(options = {}, &block)
  options   = options.dup
  @url      = options.delete(:url) || 'udp://localhost:12201'
  @max_size = options.delete(:max_size) || 'WAN'

  uri      = URI.parse(@url)
  @server  = uri.host
  @port    = uri.port
  protocol = uri.scheme.to_sym

  raise(ArgumentError, "Invalid protocol value: #{protocol}. Must be :udp or :tcp") unless [:udp, :tcp].include?(protocol)

  options[:protocol] = protocol == :tcp ? GELF::Protocol::TCP : GELF::Protocol::UDP

  @gelf_options = options
  options       = extract_subscriber_options!(options)

  super(options, &block)
  reopen
end

Instance Attribute Details

#notifier ⇒ Object (readonly)

Returns the value of attribute notifier.



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# File 'lib/semantic_logger/appender/graylog.rb', line 32

def notifier
  @notifier
end

Instance Method Details

#call(log, logger) ⇒ Object

Returns [Hash] of parameters to send



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# File 'lib/semantic_logger/appender/graylog.rb', line 100

def call(log, logger)
  h = log.to_h(host, application)
  h.delete(:time)
  h[:timestamp]     = log.time.utc.to_f
  h[:level]         = logger.map_level(log)
  h[:level_str]     = log.level.to_s
  h[:short_message] = h.delete(:message) if log.message
  h
end

#log(log) ⇒ Object

Forward log messages



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# File 'lib/semantic_logger/appender/graylog.rb', line 111

def log(log)
  return false unless should_log?(log)

  @notifier.notify!(formatter.call(log, self))
  true
end

#map_level(log) ⇒ Object

Returns the Graylog level for the supplied log message



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# File 'lib/semantic_logger/appender/graylog.rb', line 119

def map_level(log)
  LEVEL_MAP[log.level]
end

#reopen ⇒ Object

Re-open after process fork



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# File 'lib/semantic_logger/appender/graylog.rb', line 93

def reopen
  @gelf_options[:facility]        = application
  @notifier                       = GELF::Notifier.new(@server, @port, @max_size, @gelf_options)
  @notifier.collect_file_and_line = false
end